From: Thomas Mühlbacher tmuehlbacher@posteo.net

Reading the interrupt register `SJA1000_IR` causes all of its bits to be reset. If we ever reach the condition of handling more than `SJA1000_MAX_IRQ` IRQs, we will have read the register and reset all its bits but without actually handling the interrupt inside of the loop body.

This may, among other issues, cause us to never `netif_wake_queue()` again after a transmission interrupt.

Fixes: 429da1cc841b ("can: Driver for the SJA1000 CAN controller") Cc: stable@vger.kernel.org Signed-off-by: Thomas Mühlbacher tmuehlbacher@posteo.net Acked-by: Oliver Hartkopp socketcan@hartkopp.net Link: https://patch.msgid.link/20251115153437.11419-1-tmuehlbacher@posteo.net Signed-off-by: Marc Kleine-Budde mkl@pengutronix.de --- drivers/net/can/sja1000/sja1000.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/can/sja1000/sja1000.c b/drivers/net/can/sja1000/sja1000.c index 4d245857ef1c..83476af8adb5 100644 --- a/drivers/net/can/sja1000/sja1000.c +++ b/drivers/net/can/sja1000/sja1000.c @@ -548,8 +548,8 @@ irqreturn_t sja1000_interrupt(int irq, void *dev_id) if (priv->read_reg(priv, SJA1000_IER) == IRQ_OFF) goto out;

- while ((isrc = priv->read_reg(priv, SJA1000_IR)) && - (n < SJA1000_MAX_IRQ)) { + while ((n < SJA1000_MAX_IRQ) && + (isrc = priv->read_reg(priv, SJA1000_IR))) {

status = priv->read_reg(priv, SJA1000_SR); /* check for absent controller due to hw unplug */