From: Aleksander Jan Bajkowski <olek2@wp.pl>
To: hauke@hauke-m.de, davem@davemloft.net, kuba@kernel.org,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Aleksander Jan Bajkowski <olek2@wp.pl>
Subject: [PATCH net] net: lantiq: disable interrupt before sheduling NAPI
Date: Tue, 8 Jun 2021 23:21:07 +0200 [thread overview]
Message-ID: <20210608212107.222690-1-olek2@wp.pl> (raw)
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>
---
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 36dc3e5f6218..0e10d8aeffe1 100644
--- a/drivers/net/ethernet/lantiq_xrx200.c
+++ b/drivers/net/ethernet/lantiq_xrx200.c
@@ -352,8 +352,8 @@ 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
next reply other threads:[~2021-06-08 21:21 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-08 21:21 Aleksander Jan Bajkowski [this message]
2021-06-08 21:33 ` [PATCH net] net: lantiq: disable interrupt before sheduling NAPI Hauke Mehrtens
2021-06-09 2:20 ` patchwork-bot+netdevbpf
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