On Wed, May 05, 2021 at 01:43:02PM +0200, Marc Kleine-Budde wrote:
> The m_can_start_xmit() function checks if the cdev->tx_skb is NULL and
> returns with NETDEV_TX_BUSY in case tx_sbk is not NULL.
>
> There is a race condition in the m_can_tx_work_queue(), where first
> the skb is send to the driver and then the case tx_sbk is set to NULL.
> A TX complete IRQ might come in between and wake the queue, which
> results in tx_skb not being cleared yet.
>
> Fixes: f524f829b75a ("can: m_can: Create a m_can platform framework")
> Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
> ---
> Hello,
>
> compile time tested only.
>
> Marc
Thanks a lot for spotting this Marc, after initial testing this is
working very well. I don't see that error message at all now, even at
very high transmit rates, and dropped frames are reduced considerably.
(Test setup: RPi CM4, TCAN4550, 500 kbit/s CAN-FD.)
--
Regards,
Torin Cooper-Bennun
Software Engineer | maxiluxsystems.com
