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net: lantiq: disable interrupt before sheduling NAPI

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[ 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>
This commit is contained in:
Aleksander Jan Bajkowski 2021-06-08 23:21:07 +02:00 committed by Greg Kroah-Hartman
parent 2038cd15ea
commit cc4c6b1909
1 changed files with 1 additions and 1 deletions
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2
drivers/net/ethernet/lantiq_xrx200.c
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@ -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);