4422 Commits

Author SHA1 Message Date
Robert Hancock
c64fda48a3 i2c: xiic: Don't try to handle more interrupt events after error
[ Upstream commit cb6e45c9a0ad9e0f8664fd06db0227d185dc76ab ]

In xiic_process, it is possible that error events such as arbitration
lost or TX error can be raised in conjunction with other interrupt flags
such as TX FIFO empty or bus not busy. Error events result in the
controller being reset and the error returned to the calling request,
but the function could potentially try to keep handling the other
events, such as by writing more messages into the TX FIFO. Since the
transaction has already failed, this is not helpful and will just cause
issues.

This problem has been present ever since:

commit 7f9906bd7f72 ("i2c: xiic: Service all interrupts in isr")

which allowed non-error events to be handled after errors, but became
more obvious after:

commit 743e227a8959 ("i2c: xiic: Defer xiic_wakeup() and
__xiic_start_xfer() in xiic_process()")

which reworked the code to add a WARN_ON which triggers if both the
xfer_more and wakeup_req flags were set, since this combination is
not supposed to happen, but was occurring in this scenario.

Skip further interrupt handling after error flags are detected to avoid
this problem.

Fixes: 7f9906bd7f72 ("i2c: xiic: Service all interrupts in isr")
Signed-off-by: Robert Hancock <robert.hancock@calian.com>
Acked-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-27 08:37:24 +02:00
Marek Vasut
696e470e91 i2c: xiic: Defer xiic_wakeup() and __xiic_start_xfer() in xiic_process()
[ Upstream commit 743e227a895923c37a333eb2ebf3e391f00c406d ]

The __xiic_start_xfer() manipulates the interrupt flags, xiic_wakeup()
may result in return from xiic_xfer() early. Defer both to the end of
the xiic_process() interrupt thread, so that they are executed after
all the other interrupt bits handling completed and once it completely
safe to perform changes to the interrupt bits in the hardware.

Signed-off-by: Marek Vasut <marex@denx.de>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Stable-dep-of: cb6e45c9a0ad ("i2c: xiic: Don't try to handle more interrupt events after error")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-27 08:37:24 +02:00
Clark Wang
dffd25725e i2c: imx-lpi2c: fix type char overflow issue when calculating the clock cycle
[ Upstream commit e69b9bc170c6d93ee375a5cbfd15f74c0fb59bdd ]

Claim clkhi and clklo as integer type to avoid possible calculation
errors caused by data overflow.

Fixes: a55fa9d0e42e ("i2c: imx-lpi2c: add low power i2c bus driver")
Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Signed-off-by: Carlos Song <carlos.song@nxp.com>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-06-28 10:18:42 +02:00
Uwe Kleine-König
0360652bf6 i2c: sprd: Delete i2c adapter in .remove's error path
[ Upstream commit ca0aa17f2db3468fd017038d23a78e17388e2f67 ]

If pm runtime resume fails the .remove callback used to exit early. This
resulted in an error message by the driver core but the device gets
removed anyhow. This lets the registered i2c adapter stay around with an
unbound parent device.

So only skip clk disabling if resume failed, but do delete the adapter.

Fixes: 8b9ec0719834 ("i2c: Add Spreadtrum I2C controller driver")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-06-14 10:59:58 +02:00
Kees Cook
0638dcc7e7 treewide: Remove uninitialized_var() usage
commit 3f649ab728cda8038259d8f14492fe400fbab911 upstream.

Using uninitialized_var() is dangerous as it papers over real bugs[1]
(or can in the future), and suppresses unrelated compiler warnings
(e.g. "unused variable"). If the compiler thinks it is uninitialized,
either simply initialize the variable or make compiler changes.

In preparation for removing[2] the[3] macro[4], remove all remaining
needless uses with the following script:

git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \
	xargs perl -pi -e \
		's/\buninitialized_var\(([^\)]+)\)/\1/g;
		 s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;'

drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid
pathological white-space.

No outstanding warnings were found building allmodconfig with GCC 9.3.0
for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64,
alpha, and m68k.

[1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/
[2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/
[3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/
[4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/

Reviewed-by: Leon Romanovsky <leonro@mellanox.com> # drivers/infiniband and mlx4/mlx5
Acked-by: Jason Gunthorpe <jgg@mellanox.com> # IB
Acked-by: Kalle Valo <kvalo@codeaurora.org> # wireless drivers
Reviewed-by: Chao Yu <yuchao0@huawei.com> # erofs
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-06-09 10:29:01 +02:00
Reid Tonking
5d1f14beab i2c: omap: Fix standard mode false ACK readings
commit c770657bd2611b077ec1e7b1fe6aa92f249399bd upstream.

Using standard mode, rare false ACK responses were appearing with
i2cdetect tool. This was happening due to NACK interrupt triggering
ISR thread before register access interrupt was ready. Removing the
NACK interrupt's ability to trigger ISR thread lets register access
ready interrupt do this instead.

Cc: <stable@vger.kernel.org> # v3.7+
Fixes: 3b2f8f82dad7 ("i2c: omap: switch to threaded IRQ support")
Signed-off-by: Reid Tonking <reidt@ti.com>
Acked-by: Vignesh Raghavendra <vigneshr@ti.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-17 11:35:33 +02:00
Gregor Herburger
70ca826d3d i2c: ocores: generate stop condition after timeout in polling mode
[ Upstream commit f8160d3b35fc94491bb0cb974dbda310ef96c0e2 ]

In polling mode, no stop condition is generated after a timeout. This
causes SCL to remain low and thereby block the bus. If this happens
during a transfer it can cause slaves to misinterpret the subsequent
transfer and return wrong values.

To solve this, pass the ETIMEDOUT error up from ocores_process_polling()
instead of setting STATE_ERROR directly. The caller is adjusted to call
ocores_process_timeout() on error both in polling and in IRQ mode, which
will set STATE_ERROR and generate a stop condition.

Fixes: 69c8c0c0efa8 ("i2c: ocores: add polling interface")
Signed-off-by: Gregor Herburger <gregor.herburger@tq-group.com>
Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
Acked-by: Peter Korsgaard <peter@korsgaard.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Federico Vaga <federico.vaga@cern.ch>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-04-20 12:07:37 +02:00
Alexander Stein
02a78e6539 i2c: imx-lpi2c: clean rx/tx buffers upon new message
[ Upstream commit 987dd36c0141f6ab9f0fbf14d6b2ec3342dedb2f ]

When start sending a new message clear the Rx & Tx buffer pointers in
order to avoid using stale pointers.

Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Tested-by: Emanuele Ghidoli <emanuele.ghidoli@toradex.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-04-20 12:07:36 +02:00
Wei Chen
f8cbad984b i2c: xgene-slimpro: Fix out-of-bounds bug in xgene_slimpro_i2c_xfer()
commit 92fbb6d1296f81f41f65effd7f5f8c0f74943d15 upstream.

The data->block[0] variable comes from user and is a number between
0-255. Without proper check, the variable may be very large to cause
an out-of-bounds when performing memcpy in slimpro_i2c_blkwr.

Fix this bug by checking the value of writelen.

Fixes: f6505fbabc42 ("i2c: add SLIMpro I2C device driver on APM X-Gene platform")
Signed-off-by: Wei Chen <harperchen1110@gmail.com>
Cc: stable@vger.kernel.org
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-05 11:16:41 +02:00
Alexander Stein
283fdc5cfb i2c: imx-lpi2c: check only for enabled interrupt flags
[ Upstream commit 1c7885004567e8951d65a983be095f254dd20bef ]

When reading from I2C, the Tx watermark is set to 0. Unfortunately the
TDF (transmit data flag) is enabled when Tx FIFO entries is equal or less
than watermark. So it is set in every case, hence the reset default of 1.
This results in the MSR_RDF _and_ MSR_TDF flags to be set thus trying
to send Tx data on a read message.
Mask the IRQ status to filter for wanted flags only.

Fixes: a55fa9d0e42e ("i2c: imx-lpi2c: add low power i2c bus driver")
Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Tested-by: Emanuele Ghidoli <emanuele.ghidoli@toradex.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-04-05 11:16:36 +02:00
Randy Dunlap
b05664e036 i2c: rk3x: fix a bunch of kernel-doc warnings
[ Upstream commit 0582d984793d30442da88fe458674502bad1ad29 ]

Fix multiple W=1 kernel-doc warnings in i2c-rk3x.c:

drivers/i2c/busses/i2c-rk3x.c:83: warning: missing initial short description on line:
 * struct i2c_spec_values:
drivers/i2c/busses/i2c-rk3x.c:139: warning: missing initial short description on line:
 * struct rk3x_i2c_calced_timings:
drivers/i2c/busses/i2c-rk3x.c:162: warning: missing initial short description on line:
 * struct rk3x_i2c_soc_data:
drivers/i2c/busses/i2c-rk3x.c:242: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
 * Generate a START condition, which triggers a REG_INT_START interrupt.
drivers/i2c/busses/i2c-rk3x.c:261: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
 * Generate a STOP condition, which triggers a REG_INT_STOP interrupt.
drivers/i2c/busses/i2c-rk3x.c:304: warning: expecting prototype for Setup a read according to i2c(). Prototype was for rk3x_i2c_prepare_read() instead
drivers/i2c/busses/i2c-rk3x.c:335: warning: expecting prototype for Fill the transmit buffer with data from i2c(). Prototype was for rk3x_i2c_fill_transmit_buf() instead
drivers/i2c/busses/i2c-rk3x.c:535: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
 * Get timing values of I2C specification
drivers/i2c/busses/i2c-rk3x.c:552: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
 * Calculate divider values for desired SCL frequency
drivers/i2c/busses/i2c-rk3x.c:713: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
 * Calculate timing values for desired SCL frequency
drivers/i2c/busses/i2c-rk3x.c:963: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
 * Setup I2C registers for an I2C operation specified by msgs, num.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-02-22 12:50:25 +01:00
Zheyu Ma
cdcbae2c50 i2c: ismt: Fix an out-of-bounds bug in ismt_access()
[ Upstream commit 39244cc754829bf707dccd12e2ce37510f5b1f8d ]

When the driver does not check the data from the user, the variable
'data->block[0]' may be very large to cause an out-of-bounds bug.

The following log can reveal it:

[   33.995542] i2c i2c-1: ioctl, cmd=0x720, arg=0x7ffcb3dc3a20
[   33.995978] ismt_smbus 0000:00:05.0: I2C_SMBUS_BLOCK_DATA:  WRITE
[   33.996475] ==================================================================
[   33.996995] BUG: KASAN: out-of-bounds in ismt_access.cold+0x374/0x214b
[   33.997473] Read of size 18446744073709551615 at addr ffff88810efcfdb1 by task ismt_poc/485
[   33.999450] Call Trace:
[   34.001849]  memcpy+0x20/0x60
[   34.002077]  ismt_access.cold+0x374/0x214b
[   34.003382]  __i2c_smbus_xfer+0x44f/0xfb0
[   34.004007]  i2c_smbus_xfer+0x10a/0x390
[   34.004291]  i2cdev_ioctl_smbus+0x2c8/0x710
[   34.005196]  i2cdev_ioctl+0x5ec/0x74c

Fix this bug by checking the size of 'data->block[0]' first.

Fixes: 13f35ac14cd0 ("i2c: Adding support for Intel iSMT SMBus 2.0 host controller")
Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-18 11:41:26 +01:00
Hui Tang
c226717aa8 i2c: pxa-pci: fix missing pci_disable_device() on error in ce4100_i2c_probe
[ Upstream commit d78a167332e1ca8113268ed922c1212fd71b73ad ]

Using pcim_enable_device() to avoid missing pci_disable_device().

Fixes: 7e94dd154e93 ("i2c-pxa2xx: Add PCI support for PXA I2C controller")
Signed-off-by: Hui Tang <tanghui20@huawei.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-18 11:41:25 +01:00
Nam Cao
761976a617 i2c: i801: add lis3lv02d's I2C address for Vostro 5568
[ Upstream commit d6643d7207c572c1b0305ed505101f15502c6c87 ]

Dell Vostro 5568 laptop has lis3lv02d, but its i2c address is not known
to the kernel. Add this address.

Output of "cat /sys/devices/platform/lis3lv02d/position" on Dell Vostro
5568 laptop:
    - Horizontal: (-18,0,1044)
    - Front elevated: (522,-18,1080)
    - Left elevated: (-18,-360,1080)
    - Upside down: (36,108,-1134)

Signed-off-by: Nam Cao <namcaov@gmail.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-11-25 17:42:12 +01:00
Martin Tůma
71d487a82d i2c: xiic: Add platform module alias
[ Upstream commit b8caf0a0e04583fb71e21495bef84509182227ea ]

The missing "platform" alias is required for the mgb4 v4l2 driver to load
the i2c controller driver when probing the HW.

Signed-off-by: Martin Tůma <martin.tuma@digiteqautomotive.com>
Acked-by: Michal Simek <michal.simek@amd.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-11-10 17:57:53 +01:00
Liang He
becbc82919 i2c: mux-gpmux: Add of_node_put() when breaking out of loop
[ Upstream commit 6435319c34704994e19b0767f6a4e6f37439867b ]

In i2c_mux_probe(), we should call of_node_put() when breaking out
of for_each_child_of_node() which will automatically increase and
decrease the refcount.

Fixes: ac8498f0ce53 ("i2c: i2c-mux-gpmux: new driver")
Signed-off-by: Liang He <windhl@126.com>
Acked-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-25 11:17:47 +02:00
Lars-Peter Clausen
6d9f3128c0 i2c: cadence: Support PEC for SMBus block read
[ Upstream commit 9fdf6d97f03035ad5298e2d1635036c74c2090ed ]

SMBus packet error checking (PEC) is implemented by appending one
additional byte of checksum data at the end of the message. This provides
additional protection and allows to detect data corruption on the I2C bus.

SMBus block reads support variable length reads. The first byte in the read
message is the number of available data bytes.

The combination of PEC and block read is currently not supported by the
Cadence I2C driver.
 * When PEC is enabled the maximum transfer length for block reads
   increases from 33 to 34 bytes.
 * The I2C core smbus emulation layer relies on the driver updating the
   `i2c_msg` `len` field with the number of received bytes. The updated
   length is used when checking the PEC.

Add support to the Cadence I2C driver for handling SMBus block reads with
PEC. To determine the maximum transfer length uses the initial `len` value
of the `i2c_msg`. When PEC is enabled this will be 2, when it is disabled
it will be 1.

Once a read transfer is done also increment the `len` field by the amount
of received data bytes.

This change has been tested with a UCM90320 PMBus power monitor, which
requires block reads to access certain data fields, but also has PEC
enabled by default.

Fixes: df8eb5691c48 ("i2c: Add driver for Cadence I2C controller")
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Tested-by: Shubhrajyoti Datta <Shubhrajyoti.datta@amd.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-25 11:17:47 +02:00
Xu Wang
871a1e9492 i2c: Fix a potential use after free
[ Upstream commit e4c72c06c367758a14f227c847f9d623f1994ecf ]

Free the adap structure only after we are done using it.
This patch just moves the put_device() down a bit to avoid the
use after free.

Fixes: 611e12ea0f12 ("i2c: core: manage i2c bus device refcount in i2c_[get|put]_adapter")
Signed-off-by: Xu Wang <vulab@iscas.ac.cn>
[wsa: added comment to the code, added Fixes tag]
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-25 11:17:38 +02:00
Robert Hancock
911b81fca2 i2c: cadence: Change large transfer count reset logic to be unconditional
[ Upstream commit 4ca8ca873d454635c20d508261bfc0081af75cf8 ]

Problems were observed on the Xilinx ZynqMP platform with large I2C reads.
When a read of 277 bytes was performed, the controller NAKed the transfer
after only 252 bytes were transferred and returned an ENXIO error on the
transfer.

There is some code in cdns_i2c_master_isr to handle this case by resetting
the transfer count in the controller before it reaches 0, to allow larger
transfers to work, but it was conditional on the CDNS_I2C_BROKEN_HOLD_BIT
quirk being set on the controller, and ZynqMP uses the r1p14 version of
the core where this quirk is not being set. The requirement to do this to
support larger reads seems like an inherently required workaround due to
the core only having an 8-bit transfer size register, so it does not
appear that this should be conditional on the broken HOLD bit quirk which
is used elsewhere in the driver.

Remove the dependency on the CDNS_I2C_BROKEN_HOLD_BIT for this transfer
size reset logic to fix this problem.

Fixes: 63cab195bf49 ("i2c: removed work arounds in i2c driver for Zynq Ultrascale+ MPSoC")
Signed-off-by: Robert Hancock <robert.hancock@calian.com>
Reviewed-by: Shubhrajyoti Datta <Shubhrajyoti.datta@amd.com>
Acked-by: Michal Simek <michal.simek@amd.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-07-29 17:14:12 +02:00
Satish Nagireddy
6758690689 i2c: cadence: Unregister the clk notifier in error path
[ Upstream commit 3501f0c663063513ad604fb1b3f06af637d3396d ]

This patch ensures that the clock notifier is unregistered
when driver probe is returning error.

Fixes: df8eb5691c48 ("i2c: Add driver for Cadence I2C controller")
Signed-off-by: Satish Nagireddy <satish.nagireddy@getcruise.com>
Tested-by: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Michal Simek <michal.simek@amd.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-07-12 16:30:49 +02:00
Serge Semin
bf833c4848 i2c: designware: Use standard optional ref clock implementation
[ Upstream commit 27071b5cbca59d8e8f8750c199a6cbf8c9799963 ]

Even though the DW I2C controller reference clock source is requested by
the method devm_clk_get() with non-optional clock requirement the way the
clock handler is used afterwards has a pure optional clock semantic
(though in some circumstances we can get a warning about the clock missing
printed in the system console). There is no point in reimplementing that
functionality seeing the kernel clock framework already supports the
optional interface from scratch. Thus let's convert the platform driver to
using it.

Note by providing this commit we get to fix two problems. The first one
was introduced in commit c62ebb3d5f0d ("i2c: designware: Add support for
an interface clock"). It causes not having the interface clock (pclk)
enabled/disabled in case if the reference clock isn't provided. The second
problem was first introduced in commit b33af11de236 ("i2c: designware: Do
not require clock when SSCN and FFCN are provided"). Since that
modification the deferred probe procedure has been unsupported in case if
the interface clock isn't ready.

Fixes: c62ebb3d5f0d ("i2c: designware: Add support for an interface clock")
Fixes: b33af11de236 ("i2c: designware: Do not require clock when SSCN and FFCN are provided")
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-22 14:11:22 +02:00
Lucas Tanure
27fdb45723 i2c: cadence: Increase timeout per message if necessary
[ Upstream commit 96789dce043f5bff8b7d62aa28d52a7c59403a84 ]

Timeout as 1 second sets an upper limit on the length
of the transfer executed, but there is no maximum length
of a write or read message set in i2c_adapter_quirks for
this controller.

This upper limit affects devices that require sending
large firmware blobs over I2C.

To remove that limitation, calculate the minimal time
necessary, plus some wiggle room, for every message and
use it instead of the default one second, if more than
one second.

Signed-off-by: Lucas Tanure <tanureal@opensource.cirrus.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-14 18:11:56 +02:00
Nathan Chancellor
4826af9a07 i2c: at91: Initialize dma_buf in at91_twi_xfer()
[ Upstream commit 6977262c2eee111645668fe9e235ef2f5694abf7 ]

Clang warns:

  drivers/i2c/busses/i2c-at91-master.c:707:6: warning: variable 'dma_buf' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
          if (dev->use_dma) {
              ^~~~~~~~~~~~
  drivers/i2c/busses/i2c-at91-master.c:717:27: note: uninitialized use occurs here
          i2c_put_dma_safe_msg_buf(dma_buf, m_start, !ret);
                                   ^~~~~~~

Initialize dma_buf to NULL, as i2c_put_dma_safe_msg_buf() is a no-op
when the first argument is NULL, which will work for the !dev->use_dma
case.

Fixes: 03fbb903c8bf ("i2c: at91: use dma safe buffers")
Link: https://github.com/ClangBuiltLinux/linux/issues/1629
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Michael Walle <michael@walle.cc>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-14 18:11:43 +02:00
Michael Walle
d77a0f2842 i2c: at91: use dma safe buffers
[ Upstream commit 03fbb903c8bf7e53e101e8d9a7b261264317c411 ]

The supplied buffer might be on the stack and we get the following error
message:
[    3.312058] at91_i2c e0070600.i2c: rejecting DMA map of vmalloc memory

Use i2c_{get,put}_dma_safe_msg_buf() to get a DMA-able memory region if
necessary.

Fixes: 60937b2cdbf9 ("i2c: at91: add dma support")
Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-14 18:11:43 +02:00
Piyush Malgujar
8c668da61b drivers: i2c: thunderx: Allow driver to work with ACPI defined TWSI controllers
[ Upstream commit 03a35bc856ddc09f2cc1f4701adecfbf3b464cb3 ]

Due to i2c->adap.dev.fwnode not being set, ACPI_COMPANION() wasn't properly
found for TWSI controllers.

Signed-off-by: Szymon Balcerak <sbalcerak@marvell.com>
Signed-off-by: Piyush Malgujar <pmalgujar@marvell.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-06 08:33:49 +02:00
Mika Westerberg
fdcbdb3d08 i2c: ismt: Provide a DMA buffer for Interrupt Cause Logging
[ Upstream commit 17a0f3acdc6ec8b89ad40f6e22165a4beee25663 ]

Before sending a MSI the hardware writes information pertinent to the
interrupt cause to a memory location pointed by SMTICL register. This
memory holds three double words where the least significant bit tells
whether the interrupt cause of master/target/error is valid. The driver
does not use this but we need to set it up because otherwise it will
perform DMA write to the default address (0) and this will cause an
IOMMU fault such as below:

  DMAR: DRHD: handling fault status reg 2
  DMAR: [DMA Write] Request device [00:12.0] PASID ffffffff fault addr 0
        [fault reason 05] PTE Write access is not set

To prevent this from happening, provide a proper DMA buffer for this
that then gets mapped by the IOMMU accordingly.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-06 08:33:49 +02:00
Yang Yingliang
ef5374d532 i2c: mt7621: fix missing clk_disable_unprepare() on error in mtk_i2c_probe()
[ Upstream commit a2537c98a8a3b57002e54a262d180b9490bc7190 ]

Fix the missing clk_disable_unprepare() before return
from mtk_i2c_probe() in the error handling case.

Fixes: d04913ec5f89 ("i2c: mt7621: Add MediaTek MT7621/7628/7688 I2C driver")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-05-25 09:14:38 +02:00
Martin Povišer
7efb8e49f6 i2c: pasemi: Wait for write xfers to finish
commit bd8963e602c77adc76dbbbfc3417c3cf14fed76b upstream.

Wait for completion of write transfers before returning from the driver.
At first sight it may seem advantageous to leave write transfers queued
for the controller to carry out on its own time, but there's a couple of
issues with it:

 * Driver doesn't check for FIFO space.

 * The queued writes can complete while the driver is in its I2C read
   transfer path which means it will get confused by the raising of
   XEN (the 'transaction ended' signal). This can cause a spurious
   ENODATA error due to premature reading of the MRXFIFO register.

Adding the wait fixes some unreliability issues with the driver. There's
some efficiency cost to it (especially with pasemi_smb_waitready doing
its polling), but that will be alleviated once the driver receives
interrupt support.

Fixes: beb58aa39e6e ("i2c: PA Semi SMBus driver")
Signed-off-by: Martin Povišer <povik+lin@cutebit.org>
Reviewed-by: Sven Peter <sven@svenpeter.dev>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-20 09:19:39 +02:00
Peter Rosin
1c7b252a60 i2c: mux: demux-pinctrl: do not deactivate a master that is not active
[ Upstream commit 1a22aabf20adf89cb216f566913196128766f25b ]

Attempting to rollback the activation of the current master when
the current master has not been activated is bad. priv->cur_chan
and priv->cur_adap are both still zeroed out and the rollback
may result in attempts to revert an of changeset that has not been
applied and do result in calls to both del and put the zeroed out
i2c_adapter. Maybe it crashes, or whatever, but it's bad in any
case.

Fixes: e9d1a0a41d44 ("i2c: mux: demux-pinctrl: Fix an error handling path in 'i2c_demux_pinctrl_probe()'")
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-15 14:18:16 +02:00
Robert Hancock
c703292315 i2c: xiic: Make bus names unique
[ Upstream commit 1d366c2f9df8279df2adbb60471f86fc40a1c39e ]

This driver is for an FPGA logic core, so there can be arbitrarily many
instances of the bus on a given system. Previously all of the I2C bus
names were "xiic-i2c" which caused issues with lm_sensors when trying to
map human-readable names to sensor inputs because it could not properly
distinguish the busses, for example. Append the platform device name to
the I2C bus name so it is unique between different instances.

Fixes: e1d5b6598cdc ("i2c: Add support for Xilinx XPS IIC Bus Interface")
Signed-off-by: Robert Hancock <robert.hancock@calian.com>
Tested-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-15 14:18:15 +02:00
Wolfram Sang
a7ef01d25a i2c: qup: allow COMPILE_TEST
[ Upstream commit 5de717974005fcad2502281e9f82e139ca91f4bb ]

Driver builds fine with COMPILE_TEST. Enable it for wider test coverage
and easier maintenance.

Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-03-08 19:07:46 +01:00
Wolfram Sang
da9bf89344 i2c: cadence: allow COMPILE_TEST
[ Upstream commit 0b0dcb3882c8f08bdeafa03adb4487e104d26050 ]

Driver builds fine with COMPILE_TEST. Enable it for wider test coverage
and easier maintenance.

Signed-off-by: Wolfram Sang <wsa@kernel.org>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-03-08 19:07:46 +01:00
Eric Anholt
7b7c65abeb i2c: bcm2835: Avoid clock stretching timeouts
[ Upstream commit 9495b9b31abe525ebd93da58de2c88b9f66d3a0e ]

The CLKT register contains at poweron 0x40, which at our typical 100kHz
bus rate means .64ms. But there is no specified limit to how long devices
should be able to stretch the clocks, so just disable the timeout. We
still have a timeout wrapping the entire transfer.

Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
BugLink: https://github.com/raspberrypi/linux/issues/3064
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-03-08 19:07:45 +01:00
Rafał Miłecki
ba71b1b30d i2c: brcmstb: fix support for DSL and CM variants
commit 834cea3a252ed4847db076a769ad9efe06afe2d5 upstream.

DSL and CM (Cable Modem) support 8 B max transfer size and have a custom
DT binding for that reason. This driver was checking for a wrong
"compatible" however which resulted in an incorrect setup.

Fixes: e2e5a2c61837 ("i2c: brcmstb: Adding support for CM and DSL SoCs")
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-23 12:00:00 +01:00
Lakshmi Sowjanya D
bb7d1de681 i2c: designware-pci: Fix to change data types of hcnt and lcnt parameters
[ Upstream commit d52097010078c1844348dc0e467305e5f90fd317 ]

The data type of hcnt and lcnt in the struct dw_i2c_dev is of type u16.
It's better to have same data type in struct dw_scl_sda_cfg as well.

Reported-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Lakshmi Sowjanya D <lakshmi.sowjanya.d@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-27 09:19:48 +01:00
Joakim Tjernlund
e441d3cb76 i2c: mpc: Correct I2C reset procedure
[ Upstream commit ebe82cf92cd4825c3029434cabfcd2f1780e64be ]

Current I2C reset procedure is broken in two ways:
1) It only generate 1 START instead of 9 STARTs and STOP.
2) It leaves the bus Busy so every I2C xfer after the first
   fixup calls the reset routine again, for every xfer there after.

This fixes both errors.

Signed-off-by: Joakim Tjernlund <joakim.tjernlund@infinera.com>
Acked-by: Scott Wood <oss@buserror.net>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-27 09:19:47 +01:00
Heiner Kallweit
aca56c298e i2c: i801: Don't silently correct invalid transfer size
[ Upstream commit effa453168a7eeb8a562ff4edc1dbf9067360a61 ]

If an invalid block size is provided, reject it instead of silently
changing it to a supported value. Especially critical I see the case of
a write transfer with block length 0. In this case we have no guarantee
that the byte we would write is valid. When silently reducing a read to
32 bytes then we don't return an error and the caller may falsely
assume that we returned the full requested data.

If this change should break any (broken) caller, then I think we should
fix the caller.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-27 09:19:47 +01:00
Pavel Skripkin
9e4a3f47ef i2c: validate user data in compat ioctl
[ Upstream commit bb436283e25aaf1533ce061605d23a9564447bdf ]

Wrong user data may cause warning in i2c_transfer(), ex: zero msgs.
Userspace should not be able to trigger warnings, so this patch adds
validation checks for user data in compact ioctl to prevent reported
warnings

Reported-and-tested-by: syzbot+e417648b303855b91d8a@syzkaller.appspotmail.com
Fixes: 7d5cb45655f2 ("i2c compat ioctls: move to ->compat_ioctl()")
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-05 12:37:45 +01:00
Ondrej Jirman
7ff666e6fd i2c: rk3x: Handle a spurious start completion interrupt flag
[ Upstream commit 02fe0fbd8a21e183687925c3a266ae27dda9840f ]

In a typical read transfer, start completion flag is being set after
read finishes (notice ipd bit 4 being set):

trasnfer poll=0
i2c start
rk3x-i2c fdd40000.i2c: IRQ: state 1, ipd: 10
i2c read
rk3x-i2c fdd40000.i2c: IRQ: state 2, ipd: 1b
i2c stop
rk3x-i2c fdd40000.i2c: IRQ: state 4, ipd: 33

This causes I2C transfer being aborted in polled mode from a stop completion
handler:

trasnfer poll=1
i2c start
rk3x-i2c fdd40000.i2c: IRQ: state 1, ipd: 10
i2c read
rk3x-i2c fdd40000.i2c: IRQ: state 2, ipd: 0
rk3x-i2c fdd40000.i2c: IRQ: state 2, ipd: 1b
i2c stop
rk3x-i2c fdd40000.i2c: IRQ: state 4, ipd: 13
i2c stop
rk3x-i2c fdd40000.i2c: unexpected irq in STOP: 0x10

Clearing the START flag after read fixes the issue without any obvious
side effects.

This issue was dicovered on RK3566 when adding support for powering
off the RK817 PMIC.

Signed-off-by: Ondrej Jirman <megous@megous.com>
Reviewed-by: John Keeping <john@metanate.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-17 10:12:23 +01:00
Aaro Koskinen
063d223362 i2c: cbus-gpio: set atomic transfer callback
commit b12764695c3fcade145890b67f82f8b139174cc7 upstream.

CBUS transfers have always been atomic, but after commit 63b96983a5dd
("i2c: core: introduce callbacks for atomic transfers") we started to see
warnings during e.g. poweroff as the atomic callback is not explicitly set.
Fix that.

Fixes the following WARNING seen during Nokia N810 power down:

[  786.570617] reboot: Power down
[  786.573913] ------------[ cut here ]------------
[  786.578826] WARNING: CPU: 0 PID: 672 at drivers/i2c/i2c-core.h:40 i2c_smbus_xfer+0x100/0x110
[  786.587799] No atomic I2C transfer handler for 'i2c-2'

Fixes: 63b96983a5dd ("i2c: core: introduce callbacks for atomic transfers")
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-08 09:01:11 +01:00
Alain Volmat
f5d7bd03f8 i2c: stm32f7: stop dma transfer in case of NACK
commit 31b90a95ccbbb4b628578ac17e3b3cc8eeacfe31 upstream.

In case of receiving a NACK, the dma transfer should be stopped
to avoid feeding data into the FIFO.
Also ensure to properly return the proper error code and avoid
waiting for the end of the dma completion in case of
error happening during the transmission.

Fixes: 7ecc8cfde553 ("i2c: i2c-stm32f7: Add DMA support")
Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@foss.st.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-08 09:01:11 +01:00
Alain Volmat
9fce2ead76 i2c: stm32f7: recover the bus on access timeout
commit b933d1faf8fa30d16171bcff404e39c41b2a7c84 upstream.

When getting an access timeout, ensure that the bus is in a proper
state prior to returning the error.

Fixes: aeb068c57214 ("i2c: i2c-stm32f7: add driver")
Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@foss.st.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-08 09:01:11 +01:00
Alain Volmat
bc0215cbd1 i2c: stm32f7: flush TX FIFO upon transfer errors
commit 0c21d02ca469574d2082379db52d1a27b99eed0c upstream.

While handling an error during transfer (ex: NACK), it could
happen that the driver has already written data into TXDR
before the transfer get stopped.
This commit add TXDR Flush after end of transfer in case of error to
avoid sending a wrong data on any other slave upon next transfer.

Fixes: aeb068c57214 ("i2c: i2c-stm32f7: add driver")
Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@foss.st.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-08 09:01:11 +01:00
Christophe JAILLET
7f57b9bc8e i2c: xlr: Fix a resource leak in the error handling path of 'xlr_i2c_probe()'
[ Upstream commit 7f98960c046ee1136e7096aee168eda03aef8a5d ]

A successful 'clk_prepare()' call should be balanced by a corresponding
'clk_unprepare()' call in the error handling path of the probe, as already
done in the remove function.

More specifically, 'clk_prepare_enable()' is used, but 'clk_disable()' is
also already called. So just the unprepare step has still to be done.

Update the error handling path accordingly.

Fixes: 75d31c2372e4 ("i2c: xlr: add support for Sigma Designs controller variant")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-17 09:48:46 +01:00
Jamie Iles
60bacf259e i2c: acpi: fix resource leak in reconfiguration device addition
[ Upstream commit 6558b646ce1c2a872fe1c2c7cb116f05a2c1950f ]

acpi_i2c_find_adapter_by_handle() calls bus_find_device() which takes a
reference on the adapter which is never released which will result in a
reference count leak and render the adapter unremovable.  Make sure to
put the adapter after creating the client in the same manner that we do
for OF.

Fixes: 525e6fabeae2 ("i2c / ACPI: add support for ACPI reconfigure notifications")
Signed-off-by: Jamie Iles <quic_jiles@quicinc.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
[wsa: fixed title]
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-10-13 10:08:20 +02:00
Sergey Shtylyov
a0a9ecca2d i2c: mt65xx: fix IRQ check
[ Upstream commit 58fb7c643d346e2364404554f531cfa6a1a3917c ]

Iff platform_get_irq() returns 0, the driver's probe() method will return 0
early (as if the method's call was successful).  Let's consider IRQ0 valid
for simplicity -- devm_request_irq() can always override that decision...

Fixes: ce38815d39ea ("I2C: mediatek: Add driver for MediaTek I2C controller")
Signed-off-by: Sergey Shtylyov <s.shtylyov@omprussia.ru>
Reviewed-by: Qii Wang <qii.wang@mediatek.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-15 09:47:36 +02:00
Sergey Shtylyov
4be8deab6f i2c: s3c2410: fix IRQ check
[ Upstream commit d6840a5e370b7ea4fde16ce2caf431bcc87f9a75 ]

Iff platform_get_irq() returns 0, the driver's probe() method will return 0
early (as if the method's call was successful).  Let's consider IRQ0 valid
for simplicity -- devm_request_irq() can always override that decision...

Fixes: e0d1ec97853f ("i2c-s3c2410: Change IRQ to be plain integer.")
Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-15 09:47:35 +02:00
Sergey Shtylyov
da3e5f3204 i2c: iop3xx: fix deferred probing
[ Upstream commit a1299505162ad00def3573260c2c68b9c8e8d697 ]

When adding the code to handle platform_get_irq*() errors in the commit
489447380a29 ("handle errors returned by platform_get_irq*()"), the
actual error code was enforced to be -ENXIO in the driver for some
strange reason.  This didn't matter much until the deferred probing was
introduced -- which requires an actual error code to be propagated
upstream from the failure site.

While fixing this, also stop overriding the errors from request_irq() to
-EIO (done since the pre-git era).

Fixes: 489447380a29 ("[PATCH] handle errors returned by platform_get_irq*()")
Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-15 09:47:35 +02:00
Sergey Shtylyov
e39c73563a i2c: highlander: add IRQ check
[ Upstream commit f16a3bb69aa6baabf8f0aca982c8cf21e2a4f6bc ]

The driver is written as if platform_get_irq() returns 0 on errors (while
actually it returns a negative error code), blithely passing these error
codes to request_irq() (which takes *unsigned* IRQ #) -- which fails with
-EINVAL. Add the necessary error check to the pre-existing *if* statement
forcing the driver into the polling mode...

Fixes: 4ad48e6ab18c ("i2c: Renesas Highlander FPGA SMBus support")
Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-15 09:47:32 +02:00
Greg Kroah-Hartman
aa04486c41 i2c: dev: zero out array used for i2c reads from userspace
commit 86ff25ed6cd8240d18df58930bd8848b19fce308 upstream.

If an i2c driver happens to not provide the full amount of data that a
user asks for, it is possible that some uninitialized data could be sent
to userspace.  While all in-kernel drivers look to be safe, just be sure
by initializing the buffer to zero before it is passed to the i2c driver
so that any future drivers will not have this issue.

Also properly copy the amount of data recvieved to the userspace buffer,
as pointed out by Dan Carpenter.

Reported-by: Eric Dumazet <edumazet@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-08-18 08:56:56 +02:00