[PATCH 5.4 37/43] net: lantiq: Disable IRQs only if NAPI gets scheduled

Greg Kroah-Hartman
2020-09-25T12:53:17Z

From: Hauke Mehrtens <hauke@hauke-m.de>

[ Upstream commit 9423361da52356cb68642db5b2729b6b85aad330 ]

The napi_schedule() call will only schedule the NAPI if it is not
already running. To make sure that we do not deactivate interrupts
without scheduling NAPI only deactivate the interrupts in case NAPI also
gets scheduled.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/ethernet/lantiq_xrx200.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

--- a/drivers/net/ethernet/lantiq_xrx200.c
+++ b/drivers/net/ethernet/lantiq_xrx200.c
@@ -344,10 +344,12 @@ static irqreturn_t xrx200_dma_irq(int ir
{
struct xrx200_chan *ch = ptr;

- ltq_dma_disable_irq(&ch->dma);
- ltq_dma_ack_irq(&ch->dma);
+ if (napi_schedule_prep(&ch->napi)) {
+ __napi_schedule(&ch->napi);
+ ltq_dma_disable_irq(&ch->dma);
+ }

- napi_schedule(&ch->napi);
+ ltq_dma_ack_irq(&ch->dma);

return IRQ_HANDLED;
}