kernel/linux.git/drivers/net/can/flexcan.c, branch v5.10.264

can: flexcan: only change CAN state when link up in system PM

2025-04-10T12:31:01+00:00

[ Upstream commit fd99d6ed20234b83d65b9c5417794343577cf3e5 ] After a suspend/resume cycle on a down interface, it will come up as ERROR-ACTIVE. $ ip -details -s -s a s dev flexcan0 3: flexcan0: mtu 16 qdisc pfifo_fast state DOWN group default qlen 10 link/can promiscuity 0 allmulti 0 minmtu 0 maxmtu 0 can state STOPPED (berr-counter tx 0 rx 0) restart-ms 1000 $ sudo systemctl suspend $ ip -details -s -s a s dev flexcan0 3: flexcan0: mtu 16 qdisc pfifo_fast state DOWN group default qlen 10 link/can promiscuity 0 allmulti 0 minmtu 0 maxmtu 0 can state ERROR-ACTIVE (berr-counter tx 0 rx 0) restart-ms 1000 And only set CAN state to CAN_STATE_ERROR_ACTIVE when resume process has no issue, otherwise keep in CAN_STATE_SLEEPING as suspend did. Fixes: 4de349e786a3 ("can: flexcan: fix resume function") Cc: stable@vger.kernel.org Signed-off-by: Haibo Chen Link: https://patch.msgid.link/20250314110145.899179-1-haibo.chen@nxp.com Reported-by: Marc Kleine-Budde Closes: https://lore.kernel.org/all/20250314-married-polar-elephant-b15594-mkl@pengutronix.de [mkl: add newlines] Signed-off-by: Marc Kleine-Budde Signed-off-by: Sasha Levin

can: flexcan: flexcan_mailbox_read() fix return value for drop = true

2022-09-28T09:10:27+00:00

commit a09721dd47c8468b3f2fdd73f40422699ffe26dd upstream. The following happened on an i.MX25 using flexcan with many packets on the bus: The rx-offload queue reached a length more than skb_queue_len_max. In can_rx_offload_offload_one() the drop variable was set to true which made the call to .mailbox_read() (here: flexcan_mailbox_read()) to _always_ return ERR_PTR(-ENOBUFS) and drop the rx'ed CAN frame. So can_rx_offload_offload_one() returned ERR_PTR(-ENOBUFS), too. can_rx_offload_irq_offload_fifo() looks as follows: | while (1) { | skb = can_rx_offload_offload_one(offload, 0); | if (IS_ERR(skb)) | continue; | if (!skb) | break; | ... | } The flexcan driver wrongly always returns ERR_PTR(-ENOBUFS) if drop is requested, even if there is no CAN frame pending. As the i.MX25 is a single core CPU, while the rx-offload processing is active, there is no thread to process packets from the offload queue. So the queue doesn't get any shorter and this results is a tight loop. Instead of always returning ERR_PTR(-ENOBUFS) if drop is requested, return NULL if no CAN frame is pending. Changes since v1: https://lore.kernel.org/all/20220810144536.389237-1-u.kleine-koenig@pengutronix.de - don't break in can_rx_offload_irq_offload_fifo() in case of an error, return NULL in flexcan_mailbox_read() in case of no pending CAN frame instead Fixes: 4e9c9484b085 ("can: rx-offload: Prepare for CAN FD support") Link: https://lore.kernel.org/all/20220811094254.1864367-1-mkl@pengutronix.de Cc: stable@vger.kernel.org # v5.5 Suggested-by: Uwe Kleine-König Reviewed-by: Uwe Kleine-König Tested-by: Thorsten Scherer Signed-off-by: Marc Kleine-Budde Signed-off-by: Greg Kroah-Hartman

can: flexcan: flexcan_chip_freeze(): fix chip freeze for missing bitrate

2021-03-30T12:31:59+00:00

[ Upstream commit 47c5e474bc1e1061fb037d13b5000b38967eb070 ] For cases when flexcan is built-in, bitrate is still not set at registering. So flexcan_chip_freeze() generates: [ 1.860000] *** ZERO DIVIDE *** FORMAT=4 [ 1.860000] Current process id is 1 [ 1.860000] BAD KERNEL TRAP: 00000000 [ 1.860000] PC: [<402e70c8>] flexcan_chip_freeze+0x1a/0xa8 To allow chip freeze, using an hardcoded timeout when bitrate is still not set. Fixes: ec15e27cc890 ("can: flexcan: enable RX FIFO after FRZ/HALT valid") Link: https://lore.kernel.org/r/20210315231510.650593-1-angelo@kernel-space.org Signed-off-by: Angelo Dureghello [mkl: use if instead of ? operator] Signed-off-by: Marc Kleine-Budde Signed-off-by: Sasha Levin

can: flexcan: invoke flexcan_chip_freeze() to enter freeze mode

2021-03-17T16:06:11+00:00

commit c63820045e2000f05657467a08715c18c9f490d9 upstream. Invoke flexcan_chip_freeze() to enter freeze mode, since need poll freeze mode acknowledge. Fixes: e955cead03117 ("CAN: Add Flexcan CAN controller driver") Link: https://lore.kernel.org/r/20210218110037.16591-4-qiangqing.zhang@nxp.com Signed-off-by: Joakim Zhang Signed-off-by: Marc Kleine-Budde Signed-off-by: Greg Kroah-Hartman

can: flexcan: enable RX FIFO after FRZ/HALT valid

2021-03-17T16:06:11+00:00

commit ec15e27cc8904605846a354bb1f808ea1432f853 upstream. RX FIFO enable failed could happen when do system reboot stress test: [ 0.303958] flexcan 5a8d0000.can: 5a8d0000.can supply xceiver not found, using dummy regulator [ 0.304281] flexcan 5a8d0000.can (unnamed net_device) (uninitialized): Could not enable RX FIFO, unsupported core [ 0.314640] flexcan 5a8d0000.can: registering netdev failed [ 0.320728] flexcan 5a8e0000.can: 5a8e0000.can supply xceiver not found, using dummy regulator [ 0.320991] flexcan 5a8e0000.can (unnamed net_device) (uninitialized): Could not enable RX FIFO, unsupported core [ 0.331360] flexcan 5a8e0000.can: registering netdev failed [ 0.337444] flexcan 5a8f0000.can: 5a8f0000.can supply xceiver not found, using dummy regulator [ 0.337716] flexcan 5a8f0000.can (unnamed net_device) (uninitialized): Could not enable RX FIFO, unsupported core [ 0.348117] flexcan 5a8f0000.can: registering netdev failed RX FIFO should be enabled after the FRZ/HALT are valid. But the current code enable RX FIFO and FRZ/HALT at the same time. Fixes: e955cead03117 ("CAN: Add Flexcan CAN controller driver") Link: https://lore.kernel.org/r/20210218110037.16591-3-qiangqing.zhang@nxp.com Signed-off-by: Joakim Zhang Signed-off-by: Marc Kleine-Budde Signed-off-by: Greg Kroah-Hartman

can: flexcan: assert FRZ bit in flexcan_chip_freeze()

2021-03-17T16:06:11+00:00

commit 449052cfebf624b670faa040245d3feed770d22f upstream. Assert HALT bit to enter freeze mode, there is a premise that FRZ bit is asserted. This patch asserts FRZ bit in flexcan_chip_freeze, although the reset value is 1b'1. This is a prepare patch, later patch will invoke flexcan_chip_freeze() to enter freeze mode, which polling freeze mode acknowledge. Fixes: b1aa1c7a2165b ("can: flexcan: fix transition from and to freeze mode in chip_{,un}freeze") Link: https://lore.kernel.org/r/20210218110037.16591-2-qiangqing.zhang@nxp.com Signed-off-by: Joakim Zhang Signed-off-by: Marc Kleine-Budde Signed-off-by: Greg Kroah-Hartman

can: flexcan: flexcan_chip_start(): fix erroneous flexcan_transceiver_enable() during bus-off recovery

2020-11-18T15:02:34+00:00

If the CAN controller goes into bus off, the do_set_mode() callback with CAN_MODE_START can be used to recover the controller, which then calls flexcan_chip_start(). If configured, this is done automatically by the framework or manually by the user. In flexcan_chip_start() there is an explicit call to flexcan_transceiver_enable(), which does a regulator_enable() on the transceiver regulator. This results in a net usage counter increase, as there is no corresponding flexcan_transceiver_disable() in the bus off code path. This further leads to the transceiver stuck enabled, even if the CAN interface is shut down. To fix this problem the flexcan_transceiver_enable()/flexcan_transceiver_disable() are moved out of flexcan_chip_start()/flexcan_chip_stop() into flexcan_open()/flexcan_close(). Fixes: e955cead0311 ("CAN: Add Flexcan CAN controller driver") Link: https://lore.kernel.org/r/20201118150148.2664024-1-mkl@pengutronix.de Signed-off-by: Marc Kleine-Budde

can: flexcan: fix failure handling of pm_runtime_get_sync()

2020-11-15T17:24:35+00:00

pm_runtime_get_sync() will increment pm usage at first and it will resume the device later. If runtime of the device has error or device is in inaccessible state(or other error state), resume operation will fail. If we do not call put operation to decrease the reference, it will result in reference leak in the two functions flexcan_get_berr_counter() and flexcan_open(). Moreover, this device cannot enter the idle state and always stay busy or other non-idle state later. So we should fix it through adding pm_runtime_put_noidle(). Fixes: ca10989632d88 ("can: flexcan: implement can Runtime PM") Signed-off-by: Zhang Qilong Link: https://lore.kernel.org/r/20201108083000.2599705-1-zhangqilong3@huawei.com Signed-off-by: Marc Kleine-Budde

can: flexcan: flexcan_setup_stop_mode(): add missing "req_bit" to stop mode property comment

2020-11-15T17:24:35+00:00

In the patch d9b081e3fc4b ("can: flexcan: remove ack_grp and ack_bit handling from driver") the unused ack_grp and ack_bit were removed from the driver. However in the comment, the "req_bit" was accidentally removed, too. This patch adds back the "req_bit" bit. Fixes: d9b081e3fc4b ("can: flexcan: remove ack_grp and ack_bit handling from driver") Reported-by: Joakim Zhang Link: http://lore.kernel.org/r/20201014114810.2911135-1-mkl@pengutronix.de Signed-off-by: Marc Kleine-Budde

can: flexcan: flexcan_remove(): disable wakeup completely

2020-11-03T21:30:34+00:00

With below sequence, we can see wakeup default is enabled after re-load module, if it was enabled before, so we need disable wakeup in flexcan_remove(). | # cat /sys/bus/platform/drivers/flexcan/5a8e0000.can/power/wakeup | disabled | # echo enabled > /sys/bus/platform/drivers/flexcan/5a8e0000.can/power/wakeup | # cat /sys/bus/platform/drivers/flexcan/5a8e0000.can/power/wakeup | enabled | # rmmod flexcan | # modprobe flexcan | # cat /sys/bus/platform/drivers/flexcan/5a8e0000.can/power/wakeup | enabled Fixes: de3578c198c6 ("can: flexcan: add self wakeup support") Fixes: 915f9666421c ("can: flexcan: add support for DT property 'wakeup-source'") Signed-off-by: Joakim Zhang Link: https://lore.kernel.org/r/20201020184527.8190-1-qiangqing.zhang@nxp.com [mkl: streamlined commit message] Signed-off-by: Marc Kleine-Budde