1397 Commits

Author SHA1 Message Date
Linus Torvalds
b39667abcd TTY/Serial changes for 6.4-rc1
Here is the big set of tty/serial driver updates for 6.4-rc1.
 
 Nothing major, just lots of tiny, constant, forward development.  This
 includes:
   - obligatory n_gsm updates and feature additions
   - 8250_em driver updates
   - sh-sci driver updates
   - dts cleanups and updates
   - general cleanups and improvements by Ilpo and Jiri
   - other small serial driver core fixes and driver updates
 
 All of these have been in linux-next for a while with no reported
 problems.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty / serial updates from Greg KH:
 "Here is the big set of tty/serial driver updates for 6.4-rc1.

  Nothing major, just lots of tiny, constant, forward development. This
  includes:

   - obligatory n_gsm updates and feature additions

   - 8250_em driver updates

   - sh-sci driver updates

   - dts cleanups and updates

   - general cleanups and improvements by Ilpo and Jiri

   - other small serial driver core fixes and driver updates

  All of these have been in linux-next for a while with no reported
  problems"

* tag 'tty-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (87 commits)
  n_gsm: Use array_index_nospec() with index that comes from userspace
  tty: vt: drop checks for undefined VT_SINGLE_DRIVER
  tty: vt: distribute EXPORT_SYMBOL()
  tty: vt: simplify some cases in tioclinux()
  tty: vt: reformat tioclinux()
  tty: serial: sh-sci: Fix end of transmission on SCI
  tty: serial: sh-sci: Add support for tx end interrupt handling
  tty: serial: sh-sci: Fix TE setting on SCI IP
  tty: serial: sh-sci: Add RZ/G2L SCIFA DMA rx support
  tty: serial: sh-sci: Add RZ/G2L SCIFA DMA tx support
  serial: max310x: fix IO data corruption in batched operations
  serial: core: Disable uart_start() on uart_remove_one_port()
  serial: 8250: Reinit port->pm on port specific driver unbind
  serial: 8250: Add missing wakeup event reporting
  tty: serial: fsl_lpuart: use UARTMODIR register bits for lpuart32 platform
  tty: serial: fsl_lpuart: adjust buffer length to the intended size
  serial: fix TIOCSRS485 locking
  serial: make SiFive serial drivers depend on ARCH_ symbols
  tty: synclink_gt: don't allocate and pass dummy flags
  tty: serial: simplify qcom_geni_serial_send_chunk_fifo()
  ...
2023-04-27 11:46:26 -07:00
Rafael J. Wysocki
21fc506cf5 Merge branches 'acpi-bus', 'acpi-video' and 'acpi-misc'
Merge ACPI bus type driver changes, ACPI backlight driver updates and a
series of cleanups related to of.h for 6.4-rc1:

 - Ensure that ACPI notify handlers are not running after removal and
   clean up code in acpi_sb_notify() (Rafael Wysocki).

 - Remove register_backlight_delay module option and code and remove
   quirks for false-positive backlight control support advertised on
   desktop boards (Hans de Goede).

 - Replace irqdomain.h include with struct declarations in ACPI headers
   and update several pieces of code previously including of.h
   implicitly through those headers (Rob Herring).

* acpi-bus:
  ACPI: bus: Ensure that notify handlers are not running after removal
  ACPI: bus: Add missing braces to acpi_sb_notify()

* acpi-video:
  ACPI: video: Remove desktops without backlight DMI quirks
  ACPI: video: Remove register_backlight_delay module option and code

* acpi-misc:
  ACPI: Replace irqdomain.h include with struct declarations
  fpga: lattice-sysconfig-spi: Add explicit include for of.h
  tpm: atmel: Add explicit include for of.h
  virtio-mmio: Add explicit include for of.h
  pata: ixp4xx: Add explicit include for of.h
  ata: pata_macio: Add explicit include of irqdomain.h
  serial: 8250_tegra: Add explicit include for of.h
  net: rfkill-gpio: Add explicit include for of.h
  staging: iio: resolver: ad2s1210: Add explicit include for of.h
  iio: adc: ad7292: Add explicit include for of.h
2023-04-24 18:01:57 +02:00
Tony Lindgren
04e82793f0 serial: 8250: Reinit port->pm on port specific driver unbind
When we unbind a serial port hardware specific 8250 driver, the generic
serial8250 driver takes over the port. After that we see an oops about 10
seconds later. This can produce the following at least on some TI SoCs:

Unhandled fault: imprecise external abort (0x1406)
Internal error: : 1406 [#1] SMP ARM

Turns out that we may still have the serial port hardware specific driver
port->pm in use, and serial8250_pm() tries to call it after the port
specific driver is gone:

serial8250_pm [8250_base] from uart_change_pm+0x54/0x8c [serial_base]
uart_change_pm [serial_base] from uart_hangup+0x154/0x198 [serial_base]
uart_hangup [serial_base] from __tty_hangup.part.0+0x328/0x37c
__tty_hangup.part.0 from disassociate_ctty+0x154/0x20c
disassociate_ctty from do_exit+0x744/0xaac
do_exit from do_group_exit+0x40/0x8c
do_group_exit from __wake_up_parent+0x0/0x1c

Let's fix the issue by calling serial8250_set_defaults() in
serial8250_unregister_port(). This will set the port back to using
the serial8250 default functions, and sets the port->pm to point to
serial8250_pm.

Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20230418101407.12403-1-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-20 13:43:41 +02:00
Florian Fainelli
0ba9e3a13c serial: 8250: Add missing wakeup event reporting
An 8250 UART configured as a wake-up source would not have reported
itself through sysfs as being the source of wake-up, correct that.

Fixes: b3b708fa2780 ("wake up from a serial port")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20230414170241.2016255-1-f.fainelli@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-20 13:43:09 +02:00
Greg Kroah-Hartman
039535ecf1 Merge 6.3-rc6 into tty-next
We need the tty/serial fixes in here for testing.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-10 08:51:09 +02:00
Rob Herring
933c9f1905 serial: 8250_tegra: Add explicit include for of.h
With linux/acpi.h no longer implicitly including of.h, add an explicit
include of of.h to fix the following error:

drivers/tty/serial/8250/8250_tegra.c:68:15: error: implicit declaration of function 'of_alias_get_id' [-Werror=implicit-function-declaration]

Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2023-04-06 20:36:27 +02:00
Ilpo Järvinen
90b8596ac4 serial: 8250: Prevent starting up DMA Rx on THRI interrupt
Hans de Goede reported Bluetooth adapters (HCIs) connected over an UART
connection failed due corrupted Rx payload. The problem was narrowed
down to DMA Rx starting on UART_IIR_THRI interrupt. The problem occurs
despite LSR having DR bit set, which is precondition for attempting to
start DMA Rx in the first place.

From a debug patch:
[x.807834] 8250irq: iir=cc lsr+saved=60 received=0/15 ier=0f dma_t/rx/err=0/0/0
[x.808676] 8250irq: iir=c2 lsr+saved=61 received=0/0 ier=0f dma_t/rx/err=0/0/0
[x.808776] 8250irq: iir=cc lsr+saved=60 received=1/12 ier=0d dma_t/rx/err=0/1/0
[x.808870] Bluetooth: hci0: Frame reassembly failed (-84)

In the debug snippet, received field indicates 1 byte was transferred
over DMA and 12 bytes after that with the non-DMA Rx. The sole byte DMA
handled was corrupted (gets zeroed) which leads to the HCI failure.

This problem became apparent after commit e8ffbb71f783 ("serial: 8250:
use THRE & __stop_tx also with DMA") changed Tx stop behavior. Tx stop
is now triggered from a THRI interrupt.

Despite that this problem looks like a HW bug, this fix is not adding
UART_BUG_xx flag to the driver beucase it seems useful in general to
avoid starting DMA when there are only a few bytes to transfer.
Skipping DMA for small transfers avoids the extra overhead DMA incurs.

Thus, don't setup DMA Rx on UART_IIR_THRI but leave it to a subsequent
interrupt which has Rx a related IIR value.

By returning false from handle_rx_dma(), the DMA vs non-DMA decision is
postponed until either UART_IIR_RDI (FIFO threshold worth of bytes
awaiting) or UART_IIR_TIMEOUT (inter-character timeout) triggers at a
later time which allows better to discern whether the number of bytes
warrants starting DMA or not.

Reported-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Fixes: e8ffbb71f783 ("serial: 8250: use THRE & __stop_tx also with DMA")
Cc: stable@vger.kernel.org
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230317103034.12881-1-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-29 10:59:11 +02:00
Ilpo Järvinen
146a37e05d serial: 8250: Fix serial8250_tx_empty() race with DMA Tx
There's a potential race before THRE/TEMT deasserts when DMA Tx is
starting up (or the next batch of continuous Tx is being submitted).
This can lead to misdetecting Tx empty condition.

It is entirely normal for THRE/TEMT to be set for some time after the
DMA Tx had been setup in serial8250_tx_dma(). As Tx side is definitely
not empty at that point, it seems incorrect for serial8250_tx_empty()
claim Tx is empty.

Fix the race by also checking in serial8250_tx_empty() whether there's
DMA Tx active.

Note: This fix only addresses in-kernel race mainly to make using
TCSADRAIN/FLUSH robust. Userspace can still cause other races but they
seem userspace concurrency control problems.

Fixes: 9ee4b83e51f74 ("serial: 8250: Add support for dmaengine")
Cc: stable@vger.kernel.org
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230317113318.31327-3-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-29 10:55:53 +02:00
Greg Kroah-Hartman
f16a70c047 Merge 6.3-rc3 into tty-next
We need the tty/serial fixes in here and it resolves a merge conflict
with:
	drivers/tty/serial/8250/8250_em.c

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-20 09:14:37 +01:00
Doug Berger
15ac1122fd serial: 8250_bcm7271: Fix arbitration handling
The arbitration of the UART DMA is mishandled for a few
exceptional cases when probing and releasing the driver.

It is possible that the DMA register spaces are not defined in
device tree for an instance of the driver, so attempts to access
the registers in brcmuart_arbitration() would use NULL pointers.

It is also possible for the probe function to return an error
while still holding the UART DMA. This would prevent the UART
DMA from being claimed by an instance that could use it.

These errors are addressed by only releasing the UART DMA if it
is held by this instance (i.e. priv->dma_enabled == 1) and
directing early error paths in probe to this common release_dma
handling.

Fixes: 41a469482de2 ("serial: 8250: Add new 8250-core based Broadcom STB driver")
Signed-off-by: Doug Berger <opendmb@gmail.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20230309190224.687380-1-opendmb@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-17 15:01:52 +01:00
Biju Das
b22ea7df56 serial: 8250_em: Add serial8250_em_{reg_update(),out_helper()}
As per RZ/V2M hardware manual(Rev.1.30 Jun, 2022), UART IP has a
restriction as mentioned below.

40.6.1 Point for Caution when Changing the Register Settings:

When changing the settings of the following registers, a PRESETn master
reset or FIFO reset + SW reset (FCR[2],FCR[1], HCR0[7]) must be input to
re-initialize them.

Target Registers: FCR, LCR, MCR, DLL, DLM, HCR0.

Add serial8250_em_reg_update() and serial8250_em_serial_out_helper() to
handle this restriction. serial8250_em_serial_out_helper() is identical to
previous serial8250_em_serial_out() except that UART_FCR macro is removed
from serial8250_em_serial_out_helper() as it is now handled by serial8250_
em_serial_out().

DLL/DLM register can be updated only by setting LCR[7]. So the
updation of LCR[7] will perform reset for DLL/DLM register changes.

EMMA mobile has the same register set as RZ/V2M and this patch is tested on
EMEV2 board. So, there is no harm in applying the same restriction here as
well as the HW manual for EMMA mobile is not updated for a long time.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20230227114152.22265-8-biju.das.jz@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-09 17:21:54 +01:00
Biju Das
59d6558fb5 serial: 8250_em: Use pseudo offset for UART_FCR
UART_FCR shares the same offset with UART_IIR. We cannot use UART_FCR
in serial8250_em_serial_in() as it overlaps with UART_IIR.

Define UART_FCR_EM macro with a high value to avoid overlapping
with existing UART_* register defines and define another macro
UART_FCR_EM_HW for the real offset.

Use these macros in serial8250_em_serial{_in/_out} function to
read/write FCR register.

Suggested-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20230227114152.22265-7-biju.das.jz@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-09 17:21:54 +01:00
Biju Das
7eada8a122 serial: 8250_em: Use devm_clk_get_enabled()
Simplify clk handling in probe() by replacing devm_clk_get()->devm_
clk_get_enabled(). This replaces the usage of clk_prepare_enable/clk_
disable_unprepare() in probe()/remove(). After that sclk is no
longer required in struct serial8250_em_priv and is replaced by a
local variable sclk in probe().

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20230227114152.22265-6-biju.das.jz@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-09 17:21:54 +01:00
Biju Das
54769d8656 serial: 8250_em: Add missing break statement
Add missing break statement in serial8250_em_serial_out().

Suggested-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20230227114152.22265-5-biju.das.jz@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-09 17:21:54 +01:00
Biju Das
e335354d23 serial: 8250_em: Drop unused header file
Drop unused header file slab.h from the driver.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20230227114152.22265-4-biju.das.jz@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-09 17:21:54 +01:00
Biju Das
6b5f1e2e22 serial: 8250_em: Simplify probe()
Simplify probe() by using dev_err_probe() instead of dev_err() and
add a local variable 'dev' to replace '&pdev->dev'.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20230227114152.22265-3-biju.das.jz@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-09 17:21:54 +01:00
Biju Das
302a22a4fa serial: 8250_em: Fix UART port type
As per HW manual for  EMEV2 "R19UH0040EJ0400 Rev.4.00", the UART
IP found on EMMA mobile SoC is Register-compatible with the
general-purpose 16750 UART chip. Fix UART port type as 16750 and
enable 64-bytes fifo support.

Fixes: 22886ee96895 ("serial8250-em: Emma Mobile UART driver V2")
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20230227114152.22265-2-biju.das.jz@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-09 17:21:52 +01:00
Kumaravel Thiagarajan
5d943b5d69 serial: 8250_pci1xxxx: Disable SERIAL_8250_PCI1XXXX config by default
Commit 32bb477fa7bf ("serial: 8250_pci1xxxx: Add driver for quad-uart
support") made the SERIAL_8250_PCI1XXXX driver enabled when SERIAL_8250
is enabled, disable it as this driver does not need to be enabled by
default

Fixes: 32bb477fa7bf ("serial: 8250_pci1xxxx: Add driver for quad-uart support")
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/lkml/CAHk-=whhFCeeuo6vTEmNSx6S-KKkugxgzN_W5Z6v-9yH9gc3Zw@mail.gmail.com/
Signed-off-by: Kumaravel Thiagarajan <kumaravel.thiagarajan@microchip.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20230305145124.13444-1-kumaravel.thiagarajan@microchip.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-09 17:08:15 +01:00
Johan Hovold
6e01f9a594 serial: 8250_fsl: fix handle_irq locking
The 8250 handle_irq callback is not just called from the interrupt
handler but also from a timer callback when polling (e.g. for ports
without an interrupt line). Consequently the callback must explicitly
disable interrupts to avoid a potential deadlock with another interrupt
in polled mode.

Fix up the two paths in the freescale callback that failed to re-enable
interrupts when polling.

Fixes: 853a9ae29e97 ("serial: 8250: fix handle_irq locking")
Cc: stable@vger.kernel.org	# 5.13
Reported-by: Dan Carpenter <error27@gmail.com>
Link: https://lore.kernel.org/r/Y/xYzqp4ogmOF5t0@kili
Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20230227085046.24282-1-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-09 17:08:05 +01:00
Biju Das
32e293be73 serial: 8250_em: Fix UART port type
As per HW manual for  EMEV2 "R19UH0040EJ0400 Rev.4.00", the UART
IP found on EMMA mobile SoC is Register-compatible with the
general-purpose 16750 UART chip. Fix UART port type as 16750 and
enable 64-bytes fifo support.

Fixes: 22886ee96895 ("serial8250-em: Emma Mobile UART driver V2")
Cc: stable@vger.kernel.org
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20230227114152.22265-2-biju.das.jz@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-09 17:07:05 +01:00
Randy Dunlap
f8086d1a65 serial: 8250: ASPEED_VUART: select REGMAP instead of depending on it
REGMAP is a hidden (not user visible) symbol. Users cannot set it
directly thru "make *config", so drivers should select it instead of
depending on it if they need it.

Consistently using "select" or "depends on" can also help reduce
Kconfig circular dependency issues.

Therefore, change the use of "depends on REGMAP" to "select REGMAP".

Fixes: 8d310c9107a2 ("drivers/tty/serial/8250: Make Aspeed VUART SIRQ polarity configurable")
Cc: stable <stable@kernel.org>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Oskar Senft <osk@google.com>
Cc: linux-serial@vger.kernel.org
Link: https://lore.kernel.org/r/20230226053953.4681-9-rdunlap@infradead.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-09 17:06:49 +01:00
Kumaravel Thiagarajan
8cf31a99d3 serial: 8250_pci1xxxx: Add power management functions to quad-uart driver
pci1xxxx's quad-uart function has the capability to wake up UART
from suspend state. Enable wakeup before entering into suspend and
disable wakeup on resume.

Co-developed-by: Tharun Kumar P <tharunkumar.pasumarthi@microchip.com>
Signed-off-by: Tharun Kumar P <tharunkumar.pasumarthi@microchip.com>
Signed-off-by: Kumaravel Thiagarajan <kumaravel.thiagarajan@microchip.com>
Link: https://lore.kernel.org/r/20230207164814.3104605-5-kumaravel.thiagarajan@microchip.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-08 13:10:15 +01:00
Kumaravel Thiagarajan
08cedda0b3 serial: 8250_pci1xxxx: Add RS485 support to quad-uart driver
pci1xxxx uart supports RS485 mode of operation in the hardware with
auto-direction control with configurable delay for releasing RTS after
the transmission. This patch adds support for the RS485 mode.

Co-developed-by: Tharun Kumar P <tharunkumar.pasumarthi@microchip.com>
Signed-off-by: Tharun Kumar P <tharunkumar.pasumarthi@microchip.com>
Signed-off-by: Kumaravel Thiagarajan <kumaravel.thiagarajan@microchip.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230207164814.3104605-4-kumaravel.thiagarajan@microchip.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-08 13:10:15 +01:00
Kumaravel Thiagarajan
32bb477fa7 serial: 8250_pci1xxxx: Add driver for quad-uart support
pci1xxxx is a PCIe switch with a multi-function endpoint on one of
its downstream ports. Quad-uart is one of the functions in the
multi-function endpoint. This driver loads for the quad-uart and
enumerates single or multiple instances of uart based on the PCIe
subsystem device ID.

Co-developed-by: Tharun Kumar P <tharunkumar.pasumarthi@microchip.com>
Signed-off-by: Tharun Kumar P <tharunkumar.pasumarthi@microchip.com>
Signed-off-by: Kumaravel Thiagarajan <kumaravel.thiagarajan@microchip.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230207164814.3104605-3-kumaravel.thiagarajan@microchip.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-08 13:10:15 +01:00
Kumaravel Thiagarajan
0348386dab serial: 8250_pci: Add serial8250_pci_setup_port definition in 8250_pcilib.c
Move implementation of setup_port func() to serial8250_pci_setup_port.

Co-developed-by: Tharun Kumar P <tharunkumar.pasumarthi@microchip.com>
Signed-off-by: Tharun Kumar P <tharunkumar.pasumarthi@microchip.com>
Signed-off-by: Kumaravel Thiagarajan <kumaravel.thiagarajan@microchip.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230207164814.3104605-2-kumaravel.thiagarajan@microchip.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-08 13:10:15 +01:00
Greg Kroah-Hartman
f6b2ce79b5 Merge 6.2-rc7 into tty-next
We need the tty/serial fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-06 10:48:49 +01:00
Uwe Kleine-König
fbe7e38f3e serial: 8250: Fix mismerge regarding serial_lsr_in()
The relevant history introducing serial_lsr_in() looks as follows:

	$ git log --graph --oneline --boundary 9fafe733514b..df36f3e3fbb7 -- drivers/tty/serial/8250/8250_port.c
	*   df36f3e3fbb7 Merge tag 'v5.19-rc3' into tty-next
	|\
	| * be03b0651ffd serial: 8250: Store to lsr_save_flags after lsr read
	* | ...
	* | bdb70c424df1 serial: 8250: Create serial_lsr_in()
	* | ce338e4477cf serial: 8250: Store to lsr_save_flags after lsr read
	* | ...
	|/
	o 9fafe733514b tty: remove CMSPAR ifdefs

So the patch "serial: 8250: Store to lsr_save_flags after lsr read" was
introduced twice and in one branch it was followed up by commit
bdb70c424df1 ("serial: 8250: Create serial_lsr_in()") which moved
explicit lsr_saved_flags handling into a new function serial_lsr_in().
When the two branches were merged in commit df36f3e3fbb7, we got both,
serial_lsr_in() and the explicit lsr_saved_flags handling.

So drop the explicit lsr_saved_flags handling.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230202104501.264686-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-02 14:58:21 +01:00
Ilpo Järvinen
57e9af7831 serial: 8250_dma: Fix DMA Rx rearm race
As DMA Rx can be completed from two places, it is possible that DMA Rx
completes before DMA completion callback had a chance to complete it.
Once the previous DMA Rx has been completed, a new one can be started
on the next UART interrupt. The following race is possible
(uart_unlock_and_check_sysrq_irqrestore() replaced with
spin_unlock_irqrestore() for simplicity/clarity):

CPU0					CPU1
					dma_rx_complete()
serial8250_handle_irq()
  spin_lock_irqsave(&port->lock)
  handle_rx_dma()
    serial8250_rx_dma_flush()
      __dma_rx_complete()
        dma->rx_running = 0
        // Complete DMA Rx
  spin_unlock_irqrestore(&port->lock)

serial8250_handle_irq()
  spin_lock_irqsave(&port->lock)
  handle_rx_dma()
    serial8250_rx_dma()
      dma->rx_running = 1
      // Setup a new DMA Rx
  spin_unlock_irqrestore(&port->lock)

					  spin_lock_irqsave(&port->lock)
					  // sees dma->rx_running = 1
					  __dma_rx_complete()
					    dma->rx_running = 0
					    // Incorrectly complete
					    // running DMA Rx

This race seems somewhat theoretical to occur for real but handle it
correctly regardless. Check what is the DMA status before complething
anything in __dma_rx_complete().

Reported-by: Gilles BULOZ <gilles.buloz@kontron.com>
Tested-by: Gilles BULOZ <gilles.buloz@kontron.com>
Fixes: 9ee4b83e51f7 ("serial: 8250: Add support for dmaengine")
Cc: stable@vger.kernel.org
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230130114841.25749-3-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-31 11:15:16 +01:00
Ilpo Järvinen
31352811e1 serial: 8250_dma: Fix DMA Rx completion race
__dma_rx_complete() is called from two places:
  - Through the DMA completion callback dma_rx_complete()
  - From serial8250_rx_dma_flush() after IIR_RLSI or IIR_RX_TIMEOUT
The former does not hold port's lock during __dma_rx_complete() which
allows these two to race and potentially insert the same data twice.

Extend port's lock coverage in dma_rx_complete() to prevent the race
and check if the DMA Rx is still pending completion before calling
into __dma_rx_complete().

Reported-by: Gilles BULOZ <gilles.buloz@kontron.com>
Tested-by: Gilles BULOZ <gilles.buloz@kontron.com>
Fixes: 9ee4b83e51f7 ("serial: 8250: Add support for dmaengine")
Cc: stable@vger.kernel.org
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230130114841.25749-2-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-31 11:15:16 +01:00
Greg Kroah-Hartman
7a6aa989f2 Merge 6.2-rc5 into tty-next
We need the serial/tty changes into this branch as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-22 12:55:13 +01:00
Matthew Howell
14ee78d593 serial: exar: Add support for Sealevel 7xxxC serial cards
Add support for Sealevel 7xxxC serial cards.

This patch:
* Adds IDs to recognize 7xxxC cards from Sealevel Systems.
* Updates exar_pci_probe() to set nr_ports to last two bytes of primary
  dev ID for these cards.

Signed-off-by: Matthew Howell <matthew.howell@sealevel.com>
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/r/alpine.DEB.2.21.2301191440010.22558@tstest-VirtualBox
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-20 13:38:38 +01:00
Matthew Gerlach
e34a79d0b3 tty: serial: 8250: add DFL bus driver for Altera 16550.
Add a Device Feature List (DFL) bus driver for the Altera
16550 implementation of UART.

Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Marco Pagani <marpagan@redhat.com>
Link: https://lore.kernel.org/r/20230115151447.1353428-5-matthew.gerlach@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-19 16:07:40 +01:00
Ilpo Järvinen
8573b2ebce serial: 8250_early: Convert literals to use defines
Use existing defines for the serial register values in 8250_early.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20221125130509.8482-7-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-19 15:01:20 +01:00
Ilpo Järvinen
afd216ca17 serial: 8250: Define IIR 64 byte bit & cleanup related code
16750 indicates 64 bytes FIFO with a IIR bit. Add define for it and
make related code more obvious.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20221125130509.8482-6-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-19 15:01:20 +01:00
Ilpo Järvinen
3398cc4f2b serial: 8250: Add IIR FIFOs enabled field properly
Don't use magic literals & comments but define a real field instead
for UART_IIR_FIFO_ENABLED and name also the values.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20221125130509.8482-5-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-19 15:01:20 +01:00
Ilpo Järvinen
67a9aee781 serial: 8250: Cleanup MCR literals
Use proper names from MCR bits.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20221125130509.8482-4-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-19 15:01:20 +01:00
Ilpo Järvinen
d9c1d3cbde serial: 8250: Name MSR literals
Add UART_MSR_STATUS_BITS for CD, RI, DSR & CTS. Use names for the
literal.

Don't make the define for combined flags part of UAPI.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20221125130509.8482-3-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-19 15:01:19 +01:00
Ilpo Järvinen
ef460db2a7 serial: 8250: Use defined IER bits
Instead of literal 0x0f, add a define for enabling all IER bits the
8250 driver is interested in.

Don't make the define for combined flags part of UAPI.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20221125130509.8482-2-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-19 15:01:19 +01:00
Linus Torvalds
dd6f9b17cd TTY/Serial driver changes for 6.2-rc1
Here is the "big" set of tty/serial driver changes for 6.2-rc1.
 
 As in previous kernel releases, nothing big here at all, just some small
 incremental serial/tty layer cleanups and some individual driver
 additions and fixes.  Highlights are:
   - serial helper macros from Jiri Slaby to reduce the amount of
     duplicated code in serial drivers
   - api cleanups and consolidations from Ilpo Järvinen in lots of serial
     drivers
   - the usual set of n_gsm fixes from Daniel Starke as that code gets
     exercised more
   - TIOCSTI is finally able to be disabled if requested (security
     hardening feature from Kees Cook)
   - fsl_lpuart driver fixes and features added
   - other small serial driver additions and fixes
 
 All of these have been in linux-next for a while with no reported
 problems.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver updates from Greg KH:
 "Here is the "big" set of tty/serial driver changes for 6.2-rc1.

  As in previous kernel releases, nothing big here at all, just some
  small incremental serial/tty layer cleanups and some individual driver
  additions and fixes. Highlights are:

   - serial helper macros from Jiri Slaby to reduce the amount of
     duplicated code in serial drivers

   - api cleanups and consolidations from Ilpo Järvinen in lots of
     serial drivers

   - the usual set of n_gsm fixes from Daniel Starke as that code gets
     exercised more

   - TIOCSTI is finally able to be disabled if requested (security
     hardening feature from Kees Cook)

   - fsl_lpuart driver fixes and features added

   - other small serial driver additions and fixes

  All of these have been in linux-next for a while with no reported
  problems"

* tag 'tty-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (97 commits)
  serial: atmel: don't stop the transmitter when doing PIO
  serial: atmel: cleanup atmel_start+stop_tx()
  tty: serial: fsl_lpuart: switch to new dmaengine_terminate_* API
  serial: sunsab: Fix error handling in sunsab_init()
  serial: altera_uart: fix locking in polling mode
  serial: pch: Fix PCI device refcount leak in pch_request_dma()
  tty: serial: fsl_lpuart: Use pm_ptr() to avoid need to make pm __maybe_unused
  tty: serial: fsl_lpuart: Add runtime pm support
  tty: serial: fsl_lpuart: enable wakeup source for lpuart
  serdev: Replace poll loop by readx_poll_timeout() macro
  tty: synclink_gt: unwind actions in error path of net device open
  serial: stm32: move dma_request_chan() before clk_prepare_enable()
  dt-bindings: serial: xlnx,opb-uartlite: Drop 'contains' from 'xlnx,use-parity'
  serial: pl011: Do not clear RX FIFO & RX interrupt in unthrottle.
  serial: amba-pl011: avoid SBSA UART accessing DMACR register
  tty: serial: altera_jtaguart: remove struct altera_jtaguart
  tty: serial: altera_jtaguart: use uart_port::read_status_mask
  tty: serial: altera_jtaguart: remove unused altera_jtaguart::sigs
  tty: serial: altera_jtaguart: remove flag from altera_jtaguart_rx_chars()
  n_tty: Rename tail to old_tail in n_tty_read()
  ...
2022-12-16 03:31:56 -08:00
Linus Torvalds
98d0052d0d printk changes for 6.2
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Merge tag 'printk-for-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

Pull printk updates from Petr Mladek:

 - Add NMI-safe SRCU reader API. It uses atomic_inc() instead of
   this_cpu_inc() on strong load-store architectures.

 - Introduce new console_list_lock to synchronize a manipulation of the
   list of registered consoles and their flags.

   This is a first step in removing the big-kernel-lock-like behavior of
   console_lock(). This semaphore still serializes console->write()
   calbacks against:

      - each other. It primary prevents potential races between early
        and proper console drivers using the same device.

      - suspend()/resume() callbacks and init() operations in some
        drivers.

      - various other operations in the tty/vt and framebufer
        susbsystems. It is likely that console_lock() serializes even
        operations that are not directly conflicting with the
        console->write() callbacks here. This is the most complicated
        big-kernel-lock aspect of the console_lock() that will be hard
        to untangle.

 - Introduce new console_srcu lock that is used to safely iterate and
   access the registered console drivers under SRCU read lock.

   This is a prerequisite for introducing atomic console drivers and
   console kthreads. It will reduce the complexity of serialization
   against normal consoles and console_lock(). Also it should remove the
   risk of deadlock during critical situations, like Oops or panic, when
   only atomic consoles are registered.

 - Check whether the console is registered instead of enabled on many
   locations. It was a historical leftover.

 - Cleanly force a preferred console in xenfb code instead of a dirty
   hack.

 - A lot of code and comment clean ups and improvements.

* tag 'printk-for-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: (47 commits)
  printk: htmldocs: add missing description
  tty: serial: sh-sci: use setup() callback for early console
  printk: relieve console_lock of list synchronization duties
  tty: serial: kgdboc: use console_list_lock to trap exit
  tty: serial: kgdboc: synchronize tty_find_polling_driver() and register_console()
  tty: serial: kgdboc: use console_list_lock for list traversal
  tty: serial: kgdboc: use srcu console list iterator
  proc: consoles: use console_list_lock for list iteration
  tty: tty_io: use console_list_lock for list synchronization
  printk, xen: fbfront: create/use safe function for forcing preferred
  netconsole: avoid CON_ENABLED misuse to track registration
  usb: early: xhci-dbc: use console_is_registered()
  tty: serial: xilinx_uartps: use console_is_registered()
  tty: serial: samsung_tty: use console_is_registered()
  tty: serial: pic32_uart: use console_is_registered()
  tty: serial: earlycon: use console_is_registered()
  tty: hvc: use console_is_registered()
  efi: earlycon: use console_is_registered()
  tty: nfcon: use console_is_registered()
  serial_core: replace uart_console_enabled() with uart_console_registered()
  ...
2022-12-12 09:01:36 -08:00
John Ogness
452b9b2475 serial_core: replace uart_console_enabled() with uart_console_registered()
All users of uart_console_enabled() really want to know if a console
is registered. It is not reliable to check for CON_ENABLED in order
to identify if a console is registered. Use console_is_registered()
instead.

A _locked() variant is provided because uart_set_options() is always
called with the console_list_lock held and must check if a console
is registered in order to synchronize with kgdboc.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-23-john.ogness@linutronix.de
2022-12-02 11:25:01 +01:00
Greg Kroah-Hartman
42a62da0ae Merge 6.1-rc6 into tty-next
We need the tty/serial fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-22 17:38:38 +01:00
Linus Torvalds
09389357e9 TTY/Serial driver fixes for 6.1-rc6
Here are a number of small tty and serial driver fixes for 6.1-rc6.
 They all resolve reported problems:
 	- kernel doc build problems with the -rc1 serial driver
 	  documentation update
 	- n_gsm reported problems
 	- imx serial driver missing callback
 	- lots of tiny 8250 driver fixes for reported issues.
 
 All of these have been in linux-next for over a week with no reported
 problems.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-6.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver fixes from Greg KH:
 "Here are a number of small tty and serial driver fixes for 6.1-rc6.
  They all resolve reported problems:

   - kernel doc build problems with the -rc1 serial driver documentation
     update

   - n_gsm reported problems

   - imx serial driver missing callback

   - lots of tiny 8250 driver fixes for reported issues.

  All of these have been in linux-next for over a week with no reported
  problems"

* tag 'tty-6.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  docs/driver-api/miscellaneous: Remove kernel-doc of serial_core.c
  serial: 8250: Flush DMA Rx on RLSI
  serial: 8250_lpss: Use 16B DMA burst with Elkhart Lake
  serial: 8250_lpss: Configure DMA also w/o DMA filter
  serial: 8250: Fall back to non-DMA Rx if IIR_RDI occurs
  tty: n_gsm: fix sleep-in-atomic-context bug in gsm_control_send
  Revert "tty: n_gsm: replace kicktimer with delayed_work"
  Revert "tty: n_gsm: avoid call of sleeping functions from atomic context"
  serial: imx: Add missing .thaw_noirq hook
  tty: serial: fsl_lpuart: don't break the on-going transfer when global reset
  serial: 8250: omap: Flush PM QOS work on remove
  serial: 8250: omap: Fix unpaired pm_runtime_put_sync() in omap8250_remove()
  serial: 8250_omap: remove wait loop from Errata i202 workaround
  serial: 8250: omap: Fix missing PM runtime calls for omap8250_set_mctrl()
  serial: 8250: 8250_omap: Avoid RS485 RTS glitch on ->set_termios()
2022-11-18 10:59:52 -08:00
Ilpo Järvinen
1980860e0c serial: 8250: Flush DMA Rx on RLSI
Returning true from handle_rx_dma() without flushing DMA first creates
a data ordering hazard. If DMA Rx has handled any character at the
point when RLSI occurs, the non-DMA path handles any pending characters
jumping them ahead of those characters that are pending under DMA.

Fixes: 75df022b5f89 ("serial: 8250_dma: Fix RX handling")
Cc: <stable@vger.kernel.org>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20221108121952.5497-5-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-09 13:04:39 +01:00
Ilpo Järvinen
7090abd6ad serial: 8250_lpss: Use 16B DMA burst with Elkhart Lake
Configure DMA to use 16B burst size with Elkhart Lake. This makes the
bus use more efficient and works around an issue which occurs with the
previously used 1B.

The fix was initially developed by Srikanth Thokala and Aman Kumar.
This together with the previous config change is the cleaned up version
of the original fix.

Fixes: 0a9410b981e9 ("serial: 8250_lpss: Enable DMA on Intel Elkhart Lake")
Cc: <stable@vger.kernel.org> # serial: 8250_lpss: Configure DMA also w/o DMA filter
Reported-by: Wentong Wu <wentong.wu@intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20221108121952.5497-4-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-09 13:04:39 +01:00
Ilpo Järvinen
1bfcbe5805 serial: 8250_lpss: Configure DMA also w/o DMA filter
If the platform doesn't use DMA device filter (as is the case with
Elkhart Lake), whole lpss8250_dma_setup() setup is skipped. This
results in skipping also *_maxburst setup which is undesirable.
Refactor lpss8250_dma_setup() to configure DMA even if filter is not
setup.

Cc: stable <stable@kernel.org>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20221108121952.5497-3-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-09 13:04:39 +01:00
Ilpo Järvinen
a931237cbe serial: 8250: Fall back to non-DMA Rx if IIR_RDI occurs
DW UART sometimes triggers IIR_RDI during DMA Rx when IIR_RX_TIMEOUT
should have been triggered instead. Since IIR_RDI has higher priority
than IIR_RX_TIMEOUT, this causes the Rx to hang into interrupt loop.
The problem seems to occur at least with some combinations of
small-sized transfers (I've reproduced the problem on Elkhart Lake PSE
UARTs).

If there's already an on-going Rx DMA and IIR_RDI triggers, fall
graciously back to non-DMA Rx. That is, behave as if IIR_RX_TIMEOUT had
occurred.

8250_omap already considers IIR_RDI similar to this change so its
nothing unheard of.

Fixes: 75df022b5f89 ("serial: 8250_dma: Fix RX handling")
Cc: <stable@vger.kernel.org>
Co-developed-by: Srikanth Thokala <srikanth.thokala@intel.com>
Signed-off-by: Srikanth Thokala <srikanth.thokala@intel.com>
Co-developed-by: Aman Kumar <aman.kumar@intel.com>
Signed-off-by: Aman Kumar <aman.kumar@intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20221108121952.5497-2-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-09 13:04:39 +01:00
Lukas Wunner
d85bf51058 serial: 8250: 8250_omap: Fix calculation of RS485 delays
Commit 801954d1210a ("serial: 8250: 8250_omap: Support native RS485")
calculates RS485 delays from the baudrate.  The baudrate is generated
with either a 16x or 13x divisor.  The divisor is set in the Mode
Definition Register 1 (MDR1).

The commit erroneously assumes that the register stores the divisor as
a bitmask and uses a logical AND to differentiate between 16x and 13x
divisors.  However the divisor is really stored as a 3-bit mode
(see lines 363ff in include/uapi/linux/serial_reg.h).

The logical AND operation is performed with UART_OMAP_MDR1_16X_MODE,
which is defined as 0x0 and hence yields false.  So the commit always
assumes a 13x divisor.  Fix by using an equal comparison.  This works
because we never set any of the other 5 bits in the register.  (They
pertain to IrDA mode, which is not supported by the driver).

Fixes: 801954d1210a ("serial: 8250: 8250_omap: Support native RS485")
Link: https://lore.kernel.org/linux-serial/202211070440.8hWunFUN-lkp@intel.com/
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/7d5b04da13d89b8708b9543a0b125f2b6062a77b.1667977259.git.lukas@wunner.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-09 13:03:55 +01:00
Yuan Can
6a3ff85891 serial: 8250_bcm7271: Fix error handling in brcmuart_init()
A problem about 8250_bcm7271 create debugfs failed is triggered with the
following log given:

 [  324.516635] debugfs: Directory 'bcm7271-uart' with parent '/' already present!

The reason is that brcmuart_init() returns platform_driver_register()
directly without checking its return value, if platform_driver_register()
failed, it returns without destroy the newly created debugfs, resulting
the debugfs of 8250_bcm7271 can never be created later.

 brcmuart_init()
   debugfs_create_dir() # create debugfs directory
   platform_driver_register()
     driver_register()
       bus_add_driver()
         priv = kzalloc(...) # OOM happened
   # return without destroy debugfs directory

Fix by removing debugfs when platform_driver_register() returns error.

Fixes: 41a469482de2 ("serial: 8250: Add new 8250-core based Broadcom STB driver")
Signed-off-by: Yuan Can <yuancan@huawei.com>
Link: https://lore.kernel.org/r/20221109072110.117291-2-yuancan@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-09 13:03:43 +01:00
Ilpo Järvinen
56dc5074cb serial: 8250_dma: Rearm DMA Rx if more data is pending
When DMA Rx completes, the current behavior is to just exit the DMA
completion handler without future actions. If the transfer is still
on-going, UART will trigger an interrupt and that eventually rearms the
DMA Rx. The extra interrupt round-trip has an inherent latency cost
that increases the risk of FIFO overrun. In such situations, the
latency margin tends to already be less due to FIFO not being empty.

Add check into DMA Rx completion handler to detect if LSR has DR (Data
Ready) still set. DR indicates there will be more characters pending
and DMA Rx can be rearmed right away to handle them.

Cc: Gilles BULOZ <gilles.buloz@kontron.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20221107102126.56481-1-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-09 13:03:35 +01:00