From 8410adf2e38ad32f20edf6d90e049a8203f51d9e Mon Sep 17 00:00:00 2001 From: Sven Eckelmann Date: Thu, 5 Sep 2024 12:49:38 -0700 Subject: [PATCH] net: ag71xx: disable napi interrupts during probe ag71xx_probe is registering ag71xx_interrupt as handler for gmac0/gmac1 interrupts. The handler is trying to use napi_schedule to handle the processing of packets. But the netif_napi_add for this device is called a lot later in ag71xx_probe. It can therefore happen that a still running gmac0/gmac1 is triggering the interrupt handler with a bit from AG71XX_INT_POLL set in AG71XX_REG_INT_STATUS. The handler will then call napi_schedule and the napi code will crash the system because the ag->napi is not yet initialized. The gmcc0/gmac1 must be brought in a state in which it doesn't signal a AG71XX_INT_POLL related status bits as interrupt before registering the interrupt handler. ag71xx_hw_start will take care of re-initializing the AG71XX_REG_INT_ENABLE. This will become relevant when dual GMAC devices get added here. Signed-off-by: Sven Eckelmann Signed-off-by: Rosen Penev Link: https://patch.msgid.link/20240905194938.8453-8-rosenp@gmail.com Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/atheros/ag71xx.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/net/ethernet/atheros/ag71xx.c b/drivers/net/ethernet/atheros/ag71xx.c index e28a4b018b11..96a6189cc31e 100644 --- a/drivers/net/ethernet/atheros/ag71xx.c +++ b/drivers/net/ethernet/atheros/ag71xx.c @@ -1850,6 +1850,12 @@ static int ag71xx_probe(struct platform_device *pdev) if (!ag->mac_base) return -ENOMEM; + /* ensure that HW is in manual polling mode before interrupts are + * activated. Otherwise ag71xx_interrupt might call napi_schedule + * before it is initialized by netif_napi_add. + */ + ag71xx_int_disable(ag, AG71XX_INT_POLL); + ndev->irq = platform_get_irq(pdev, 0); err = devm_request_irq(&pdev->dev, ndev->irq, ag71xx_interrupt, 0x0, dev_name(&pdev->dev), ndev); -- 2.25.1