Commit Graph

12 Commits

Author SHA1 Message Date
eb69c07eca can: rcar_canfd: rcar_canfd_handle_global_receive(): fix IRQ storm on global FIFO receive
commit 702de2c21e upstream.

We are seeing an IRQ storm on the global receive IRQ line under heavy
CAN bus load conditions with both CAN channels enabled.

Conditions:

The global receive IRQ line is shared between can0 and can1, either of
the channels can trigger interrupt while the other channel's IRQ line
is disabled (RFIE).

When global a receive IRQ interrupt occurs, we mask the interrupt in
the IRQ handler. Clearing and unmasking of the interrupt is happening
in rx_poll(). There is a race condition where rx_poll() unmasks the
interrupt, but the next IRQ handler does not mask the IRQ due to
NAPIF_STATE_MISSED flag (e.g.: can0 RX FIFO interrupt is disabled and
can1 is triggering RX interrupt, the delay in rx_poll() processing
results in setting NAPIF_STATE_MISSED flag) leading to an IRQ storm.

This patch fixes the issue by checking IRQ active and enabled before
handling the IRQ on a particular channel.

Fixes: dd3bd23eb4 ("can: rcar_canfd: Add Renesas R-Car CAN FD driver")
Suggested-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/all/20221025155657.1426948-2-biju.das.jz@bp.renesas.com
Cc: stable@vger.kernel.org
[mkl: adjust commit message]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
[biju: removed gpriv from RCANFD_RFCC_RFIE macro]
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-03 23:57:54 +09:00
efdd92c18e can: rcar_canfd: rcar_canfd_channel_probe(): register the CAN device when fully ready
[ Upstream commit c5048a7b2c ]

Register the CAN device only when all the necessary initialization is
completed. This patch makes sure all the data structures and locks are
initialized before registering the CAN device.

Link: https://lore.kernel.org/all/20220221225935.12300-1-prabhakar.mahadev-lad.rj@bp.renesas.com
Reported-by: Pavel Machek <pavel@denx.de>
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Pavel Machek <pavel@denx.de>
Reviewed-by: Ulrich Hecht <uli+renesas@fpond.eu>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-03-19 13:44:45 +01:00
ac9921ded2 can: rcar: use devm_platform_ioremap_resource() to simplify code
Use devm_platform_ioremap_resource() to simplify the code a bit.
This is detected by coccinelle.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2019-11-11 21:58:10 +01:00
13dfb3fa49 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Just minor overlapping changes in the conflicts here.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-06 18:44:57 -07:00
d1a55841ab net: Remove dev_err() usage after platform_get_irq()
We don't need dev_err() messages when platform_get_irq() fails now that
platform_get_irq() prints an error message itself when something goes
wrong. Let's remove these prints with a simple semantic patch.

// <smpl>
@@
expression ret;
struct platform_device *E;
@@

ret =
(
platform_get_irq(E, ...)
|
platform_get_irq_byname(E, ...)
);

if ( \( ret < 0 \| ret <= 0 \) )
{
(
-if (ret != -EPROBE_DEFER)
-{ ...
-dev_err(...);
-... }
|
...
-dev_err(...);
)
...
}
// </smpl>

While we're here, remove braces on if statements that only have one
statement (manually).

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: Saeed Mahameed <saeedm@mellanox.com>
Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Cc: Felix Fietkau <nbd@nbd.name>
Cc: Lorenzo Bianconi <lorenzo@kernel.org>
Cc: netdev@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-07-30 14:37:35 -07:00
d4b890aec4 can: rcar_canfd: fix possible IRQ storm on high load
We have observed rcar_canfd driver entering IRQ storm under high load,
with following scenario:
- rcar_canfd_global_interrupt() in entered due to Rx available,
- napi_schedule_prep() is called, and sets NAPIF_STATE_SCHED in state
- Rx fifo interrupts are masked,
- rcar_canfd_global_interrupt() is entered again, this time due to
  error interrupt (e.g. due to overflow),
- since scheduled napi poller has not yet executed, condition for calling
  napi_schedule_prep() from rcar_canfd_global_interrupt() remains true,
  thus napi_schedule_prep() gets called and sets NAPIF_STATE_MISSED flag
  in state,
- later, napi poller function rcar_canfd_rx_poll() gets executed, and
  calls napi_complete_done(),
- due to NAPIF_STATE_MISSED flag in state, this call does not clear
  NAPIF_STATE_SCHED flag from state,
- on return from napi_complete_done(), rcar_canfd_rx_poll() unmasks Rx
  interrutps,
- Rx interrupt happens, rcar_canfd_global_interrupt() gets called
  and calls napi_schedule_prep(),
- since NAPIF_STATE_SCHED is set in state at this time, this call
  returns false,
- due to that false return, rcar_canfd_global_interrupt() returns
  without masking Rx interrupt
- and this results into IRQ storm: unmasked Rx interrupt happens again
  and again is misprocessed in the same way.

This patch fixes that scenario by unmasking Rx interrupts only when
napi_complete_done() returns true, which means it has cleared
NAPIF_STATE_SCHED in state.

Fixes: dd3bd23eb4 ("can: rcar_canfd: Add Renesas R-Car CAN FD driver")
Signed-off-by: Nikita Yushchenko <nikita.yoush@cogentembedded.com>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2019-07-24 11:07:57 +02:00
7af42e50f6 can: rcar: use SPDX identifier for Renesas drivers
Adopt the SPDX license identifier headers to ease license compliance
management.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2018-11-28 16:19:53 +01:00
ad61dd303a scripts/spelling.txt: add regsiter -> register spelling mistake
This typo is quite common.  Fix it and add it to the spelling file so
that checkpatch catches it earlier.

Link: http://lkml.kernel.org/r/20170317011131.6881-2-sboyd@codeaurora.org
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-05-08 17:15:13 -07:00
6ad20165d3 drivers: net: generalize napi_complete_done()
napi_complete_done() allows to opt-in for gro_flush_timeout,
added back in linux-3.19, commit 3b47d30396
("net: gro: add a per device gro flush timer")

This allows for more efficient GRO aggregation without
sacrifying latencies.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-30 15:10:42 -05:00
926f10359a can: rcar_canfd: Add back-to-error-active support
As per Wolfgang G, all new drivers should support decreasing state
transition(back-to-error-active). This patch adds this support.

This driver configures the controller to halt on bus-off entry. Hence,
when in error states less than bus off state, the TEC/REC counters
are checked for lower state transition eligibility and action.

Signed-off-by: Ramesh Shanmugasundaram <ramesh.shanmugasundaram@bp.renesas.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2016-06-23 11:23:49 +02:00
6f4c2eea35 can: rcar_canfd: Add Classical CAN only mode support
The controller can operate in one of the two global modes
 - CAN FD only mode (default)
 - Classical CAN (CAN2.0) only mode

This patch adds support for Classical CAN only mode. It can be enabled
by defining the optional device tree property "renesas,no-can-fd" of this
node.

Note: R-Car Gen3 h/w manual v0.51E shows bit6 of RSCFDnCFDGCFG as
reserved, which is incorrect. This bit is same as RSCFDnGCFG.

Signed-off-by: Ramesh Shanmugasundaram <ramesh.shanmugasundaram@bp.renesas.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2016-06-23 11:23:49 +02:00
dd3bd23eb4 can: rcar_canfd: Add Renesas R-Car CAN FD driver
This patch adds support for the CAN FD controller found in Renesas R-Car
SoCs. The controller operates in CAN FD only mode by default.

CAN FD mode supports both Classical CAN & CAN FD frame formats. The
controller supports ISO 11898-1:2015 CAN FD format only.

This controller supports two channels and the driver can enable either
or both of the channels.

Driver uses Rx FIFOs (one per channel) for reception & Common FIFOs (one
per channel) for transmission. Rx filter rules are configured to the
minimum (one per channel) and it accepts Standard, Extended, Data &
Remote Frame combinations.

Note: There are few documentation errors in R-Car Gen3 Hardware User
Manual v0.5E with respect to CAN FD controller. They are listed below:

1. CAN FD interrupt numbers 29 & 30 are listed as per channel
interrupts. However, they are common to both channels (i.e.) they are
global and channel interrupts respectively.

2. CANFD clock is derived from PLL1. This is not documented.

3. CANFD clock is further divided by (1/2) within the CAN FD controller.
This is not documented.

4. The minimum value of NTSEG1 in RSCFDnCFDCmNCFG register is 2 Tq. It
is specified 4 Tq in the manual.

5. The maximum number of message RAM area the controller can use is 3584
bytes. It is specified 10752 bytes in the manual.

Signed-off-by: Ramesh Shanmugasundaram <ramesh.shanmugasundaram@bp.renesas.com>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2016-06-17 15:39:47 +02:00