This is a note to let you know that I've just added the patch titled net: renesas: ravb: Fix a stuck issue when a lot of frames are received to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-renesas-ravb-fix-a-stuck-issue-when-a-lot-of-fra.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 1b5d0e5e82e2d754ad3be2fe7606d018b977517f Author: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx> Date: Wed Apr 21 13:52:46 2021 +0900 net: renesas: ravb: Fix a stuck issue when a lot of frames are received [ Upstream commit 5718458b092bf6bf4482c5df32affba3c3259517 ] When a lot of frames were received in the short term, the driver caused a stuck of receiving until a new frame was received. For example, the following command from other device could cause this issue. $ sudo ping -f -l 1000 -c 1000 <this driver's ipaddress> The previous code always cleared the interrupt flag of RX but checks the interrupt flags in ravb_poll(). So, ravb_poll() could not call ravb_rx() in the next time until a new RX frame was received if ravb_rx() returned true. To fix the issue, always calls ravb_rx() regardless the interrupt flags condition. Fixes: c156633f1353 ("Renesas Ethernet AVB driver proper") Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c index bd30505fbc57..f96eed67e1a2 100644 --- a/drivers/net/ethernet/renesas/ravb_main.c +++ b/drivers/net/ethernet/renesas/ravb_main.c @@ -911,31 +911,20 @@ static int ravb_poll(struct napi_struct *napi, int budget) int q = napi - priv->napi; int mask = BIT(q); int quota = budget; - u32 ris0, tis; - for (;;) { - tis = ravb_read(ndev, TIS); - ris0 = ravb_read(ndev, RIS0); - if (!((ris0 & mask) || (tis & mask))) - break; + /* Processing RX Descriptor Ring */ + /* Clear RX interrupt */ + ravb_write(ndev, ~(mask | RIS0_RESERVED), RIS0); + if (ravb_rx(ndev, "a, q)) + goto out; - /* Processing RX Descriptor Ring */ - if (ris0 & mask) { - /* Clear RX interrupt */ - ravb_write(ndev, ~(mask | RIS0_RESERVED), RIS0); - if (ravb_rx(ndev, "a, q)) - goto out; - } - /* Processing TX Descriptor Ring */ - if (tis & mask) { - spin_lock_irqsave(&priv->lock, flags); - /* Clear TX interrupt */ - ravb_write(ndev, ~(mask | TIS_RESERVED), TIS); - ravb_tx_free(ndev, q, true); - netif_wake_subqueue(ndev, q); - spin_unlock_irqrestore(&priv->lock, flags); - } - } + /* Processing RX Descriptor Ring */ + spin_lock_irqsave(&priv->lock, flags); + /* Clear TX interrupt */ + ravb_write(ndev, ~(mask | TIS_RESERVED), TIS); + ravb_tx_free(ndev, q, true); + netif_wake_subqueue(ndev, q); + spin_unlock_irqrestore(&priv->lock, flags); napi_complete(napi);