kernel.git/drivers/net/can/dev/rx-offload.c, branch linux-5.16.y

can: do not increase rx statistics when generating a CAN rx error message frame

2022-01-27T11:02:30Z

[ Upstream commit 676068db69b847f06fe054fca15bf6b107bd24da ] The CAN error message frames (i.e. error skb) are an interface specific to socket CAN. The payload of the CAN error message frames does not correspond to any actual data sent on the wire. Only an error flag and a delimiter are transmitted when an error occurs (c.f. ISO 11898-1 section 10.4.4.2 "Error flag"). For this reason, it makes no sense to increment the rx_packets and rx_bytes fields of struct net_device_stats because no actual payload were transmitted on the wire. This patch fixes all the CAN drivers. Link: https://lore.kernel.org/all/20211207121531.42941-2-mailhol.vincent@wanadoo.fr CC: Marc Kleine-Budde CC: Nicolas Ferre CC: Alexandre Belloni CC: Ludovic Desroches CC: Chandrasekar Ramakrishnan CC: Maxime Ripard CC: Chen-Yu Tsai CC: Jernej Skrabec CC: Appana Durga Kedareswara rao CC: Naga Sureshkumar Relli CC: Michal Simek CC: Stephane Grosjean Tested-by: Jimmy Assarsson # kvaser Signed-off-by: Vincent Mailhol Acked-by: Stefan Mätje # esd_usb2 Tested-by: Stefan Mätje # esd_usb2 Signed-off-by: Marc Kleine-Budde Signed-off-by: Sasha Levin

can: rx-offload: can_rx_offload_threaded_irq_finish(): add new function to be called from threaded interrupt

2021-07-25T09:36:25Z

After reading all CAN frames from the controller in the IRQ handler and storing them into a skb_queue, the driver calls napi_schedule(). In the napi poll function the skb from the skb_queue are then pushed into the networking stack. However if napi_schedule() is called from a threaded IRQ handler this triggers the following error: | NOHZ tick-stop error: Non-RCU local softirq work is pending, handler #08!!! To avoid this, create a new rx-offload function (can_rx_offload_threaded_irq_finish()) with a call to local_bh_disable()/local_bh_enable() around the napi_schedule() call. Convert all drivers that call can_rx_offload_irq_finish() from threaded IRQ context to can_rx_offload_threaded_irq_finish(). Link: https://lore.kernel.org/r/20210724204745.736053-4-mkl@pengutronix.de Suggested-by: Daniel Glöckner Tested-by: Oleksij Rempel Signed-off-by: Marc Kleine-Budde

can: rx-offload: can_rx_offload_irq_finish(): directly call napi_schedule()

2021-07-25T09:36:25Z

Instead of calling can_rx_offload_schedule() call napi_schedule() directly. As this was the last use of can_rx_offload_schedule() remove this helper function. Link: https://lore.kernel.org/r/20210724204745.736053-3-mkl@pengutronix.de Tested-by: Oleksij Rempel Signed-off-by: Marc Kleine-Budde

can: rx-offload: add skb queue for use during ISR

2021-07-25T09:36:25Z

Adding a skb to the skb_queue in rx-offload requires to take a lock. This commit avoids this by adding an unlocked skb queue that is appended at the end of the ISR. Having one lock at the end of the ISR should be OK as the HW is empty, not about to overflow. Link: https://lore.kernel.org/r/20210724204745.736053-2-mkl@pengutronix.de Tested-by: Oleksij Rempel Co-developed-by: Kurt Van Dijck Signed-off-by: Kurt Van Dijck Signed-off-by: Marc Kleine-Budde

can: dev: can_rx_offload_get_echo_skb(): extend to return can frame length

2021-01-14T07:43:43Z

In order to implement byte queue limits (bql) in CAN drivers, the length of the CAN frame needs to be passed into the networking stack after queueing and after transmission completion. To avoid to calculate this length twice, extend can_rx_offload_get_echo_skb() to return that value. Convert all users of this function, too. Reviewed-by: Vincent Mailhol Link: https://lore.kernel.org/r/20210111141930.693847-15-mkl@pengutronix.de Signed-off-by: Marc Kleine-Budde

can: dev: extend struct can_skb_priv to hold CAN frame length

2021-01-14T07:43:42Z

In order to implement byte queue limits (bql) in CAN drivers, the length of the CAN frame needs to be passed into the networking stack after queueing and after transmission completion. To avoid to calculate this length twice, extend the struct can_skb_priv to hold the length of the CAN frame and extend __can_get_echo_skb() to return that value. Reviewed-by: Vincent Mailhol Link: https://lore.kernel.org/r/20210111141930.693847-12-mkl@pengutronix.de Signed-off-by: Marc Kleine-Budde

can: dev: move driver related infrastructure into separate subdir

2021-01-13T08:42:58Z

This patch moves the CAN driver related infrastructure into a separate subdir. It will be split into more files in the coming patches. Reviewed-by: Vincent Mailhol Link: https://lore.kernel.org/r/20210111141930.693847-3-mkl@pengutronix.de Signed-off-by: Marc Kleine-Budde