From cc4c6b19093ca213a04c4b5305b5bff9791be9a1 Mon Sep 17 00:00:00 2001 From: Aleksander Jan Bajkowski Date: Tue, 8 Jun 2021 23:21:07 +0200 Subject: [PATCH] net: lantiq: disable interrupt before sheduling NAPI [ 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 Acked-by: Hauke Mehrtens Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- 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);