| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.4 11/90] net: lantiq: disable interrupt before sheduling NAPI | Date | Mon, 21 Jun 2021 18:14:46 +0200 |
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From: Aleksander Jan Bajkowski <olek2@wp.pl>
[ Upstream commit f2386cf7c5f4ff5d7b584f5d92014edd7df6c676 ]
This patch fixes TX hangs with threaded NAPI enabled. The scheduled NAPI seems to be executed in parallel with the interrupt on second thread. Sometimes it happens that ltq_dma_disable_irq() is executed after xrx200_tx_housekeeping(). The symptom is that TX interrupts are disabled in the DMA controller. As a result, the TX hangs after a few seconds of the iperf test. Scheduling NAPI after disabling interrupts fixes this issue.
Tested on Lantiq xRX200 (BT Home Hub 5A).
Fixes: 9423361da523 ("net: lantiq: Disable IRQs only if NAPI gets scheduled ") Signed-off-by: Aleksander Jan Bajkowski <olek2@wp.pl> Acked-by: Hauke Mehrtens <hauke@hauke-m.de> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> --- drivers/net/ethernet/lantiq_xrx200.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/lantiq_xrx200.c b/drivers/net/ethernet/lantiq_xrx200.c index 6ece99e6b6dd..8d073b895fc0 100644 --- a/drivers/net/ethernet/lantiq_xrx200.c +++ b/drivers/net/ethernet/lantiq_xrx200.c @@ -351,8 +351,8 @@ static irqreturn_t xrx200_dma_irq(int irq, void *ptr) struct xrx200_chan *ch = ptr; 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); -- 2.30.2
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