6.5-stable review patch. If anyone has any objections, please let me know.
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From: Christian Marangi ansuelsmth@gmail.com
commit fcdfc462881d8acf9db77f483b2c821e286ca97b upstream.
While searching for possible refactor of napi_schedule_prep and __napi_schedule it was notice that the mtk eth driver disable the interrupt for rx and tx AFTER napi is scheduled.
While this is a very hard to repro case it might happen to have situation where the interrupt is disabled and never enabled again as the napi completes and the interrupt is enabled before.
This is caused by the fact that a napi driven by interrupt expect a logic with: 1. interrupt received. napi prepared -> interrupt disabled -> napi scheduled 2. napi triggered. ring cleared -> interrupt enabled -> wait for new interrupt
To prevent this case, disable the interrupt BEFORE the napi is scheduled.
Fixes: 656e705243fd ("net-next: mediatek: add support for MT7623 ethernet") Cc: stable@vger.kernel.org Signed-off-by: Christian Marangi ansuelsmth@gmail.com Link: https://lore.kernel.org/r/20231002140805.568-1-ansuelsmth@gmail.com Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/mediatek/mtk_eth_soc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c @@ -3036,8 +3036,8 @@ static irqreturn_t mtk_handle_irq_rx(int
eth->rx_events++; if (likely(napi_schedule_prep(ð->rx_napi))) { - __napi_schedule(ð->rx_napi); mtk_rx_irq_disable(eth, eth->soc->txrx.rx_irq_done_mask); + __napi_schedule(ð->rx_napi); }
return IRQ_HANDLED; @@ -3049,8 +3049,8 @@ static irqreturn_t mtk_handle_irq_tx(int
eth->tx_events++; if (likely(napi_schedule_prep(ð->tx_napi))) { - __napi_schedule(ð->tx_napi); mtk_tx_irq_disable(eth, MTK_TX_DONE_INT); + __napi_schedule(ð->tx_napi); }
return IRQ_HANDLED;