[PATCH 5.15 127/917] can: mcp251xfd: mcp251xfd_irq(): add missing can_rx_offload_threaded_irq_finish() in case of bus off

From: Greg Kroah-Hartman
Date: Mon Nov 15 2021 - 18:31:29 EST


From: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>

commit 691204bd66b34ba982e19988e6eba9f6321dfe6c upstream.

The function can_rx_offload_threaded_irq_finish() is needed to trigger
the NAPI thread to deliver read CAN frames to the networking stack.

This patch adds the missing call to can_rx_offload_threaded_irq_finish()
in case of a bus off, before leaving the interrupt handler to avoid
packet starvation.

Link: https://lore.kernel.org/all/20211106201526.44292-1-mkl@xxxxxxxxxxxxxx
Fixes: 30bfec4fec59 ("can: rx-offload: can_rx_offload_threaded_irq_finish(): add new function to be called from threaded interrupt")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
+++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
@@ -2290,8 +2290,10 @@ static irqreturn_t mcp251xfd_irq(int irq
* check will fail, too. So leave IRQ handler
* directly.
*/
- if (priv->can.state == CAN_STATE_BUS_OFF)
+ if (priv->can.state == CAN_STATE_BUS_OFF) {
+ can_rx_offload_threaded_irq_finish(&priv->offload);
return IRQ_HANDLED;
+ }
}

handled = IRQ_HANDLED;