5.15-stable review patch. If anyone has any objections, please let me know.
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From: Thomas Mühlbacher tmuehlbacher@posteo.net
commit 30db4451c7f6aabcada029b15859a76962ec0cf8 upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/can/sja1000/sja1000.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/net/can/sja1000/sja1000.c +++ b/drivers/net/can/sja1000/sja1000.c @@ -508,8 +508,8 @@ irqreturn_t sja1000_interrupt(int irq, v 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 */