This is a note to let you know that I've just added the patch titled net/sonic: Clear interrupt flags immediately to the 5.4-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-sonic-clear-interrupt-flags-immediately.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 5fedabf5a70be26b19d7520f09f12a62274317c6 Mon Sep 17 00:00:00 2001 From: Finn Thain <fthain@xxxxxxxxxxxxxxxxxxx> Date: Thu, 23 Jan 2020 09:07:26 +1100 Subject: net/sonic: Clear interrupt flags immediately From: Finn Thain <fthain@xxxxxxxxxxxxxxxxxxx> commit 5fedabf5a70be26b19d7520f09f12a62274317c6 upstream. The chip can change a packet's descriptor status flags at any time. However, an active interrupt flag gets cleared rather late. This allows a race condition that could theoretically lose an interrupt. Fix this by clearing asserted interrupt flags immediately. Fixes: efcce839360f ("[PATCH] macsonic/jazzsonic network drivers update") Tested-by: Stan Johnson <userm57@xxxxxxxxx> Signed-off-by: Finn Thain <fthain@xxxxxxxxxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/ethernet/natsemi/sonic.c | 28 ++++++---------------------- 1 file changed, 6 insertions(+), 22 deletions(-) --- a/drivers/net/ethernet/natsemi/sonic.c +++ b/drivers/net/ethernet/natsemi/sonic.c @@ -304,10 +304,11 @@ static irqreturn_t sonic_interrupt(int i } do { + SONIC_WRITE(SONIC_ISR, status); /* clear the interrupt(s) */ + if (status & SONIC_INT_PKTRX) { netif_dbg(lp, intr, dev, "%s: packet rx\n", __func__); sonic_rx(dev); /* got packet(s) */ - SONIC_WRITE(SONIC_ISR, SONIC_INT_PKTRX); /* clear the interrupt */ } if (status & SONIC_INT_TXDN) { @@ -362,7 +363,6 @@ static irqreturn_t sonic_interrupt(int i if (freed_some || lp->tx_skb[entry] == NULL) netif_wake_queue(dev); /* The ring is no longer full */ lp->cur_tx = entry; - SONIC_WRITE(SONIC_ISR, SONIC_INT_TXDN); /* clear the interrupt */ } /* @@ -372,42 +372,31 @@ static irqreturn_t sonic_interrupt(int i netif_dbg(lp, rx_err, dev, "%s: rx fifo overrun\n", __func__); lp->stats.rx_fifo_errors++; - SONIC_WRITE(SONIC_ISR, SONIC_INT_RFO); /* clear the interrupt */ } if (status & SONIC_INT_RDE) { netif_dbg(lp, rx_err, dev, "%s: rx descriptors exhausted\n", __func__); lp->stats.rx_dropped++; - SONIC_WRITE(SONIC_ISR, SONIC_INT_RDE); /* clear the interrupt */ } if (status & SONIC_INT_RBAE) { netif_dbg(lp, rx_err, dev, "%s: rx buffer area exceeded\n", __func__); lp->stats.rx_dropped++; - SONIC_WRITE(SONIC_ISR, SONIC_INT_RBAE); /* clear the interrupt */ } /* counter overruns; all counters are 16bit wide */ - if (status & SONIC_INT_FAE) { + if (status & SONIC_INT_FAE) lp->stats.rx_frame_errors += 65536; - SONIC_WRITE(SONIC_ISR, SONIC_INT_FAE); /* clear the interrupt */ - } - if (status & SONIC_INT_CRC) { + if (status & SONIC_INT_CRC) lp->stats.rx_crc_errors += 65536; - SONIC_WRITE(SONIC_ISR, SONIC_INT_CRC); /* clear the interrupt */ - } - if (status & SONIC_INT_MP) { + if (status & SONIC_INT_MP) lp->stats.rx_missed_errors += 65536; - SONIC_WRITE(SONIC_ISR, SONIC_INT_MP); /* clear the interrupt */ - } /* transmit error */ - if (status & SONIC_INT_TXER) { + if (status & SONIC_INT_TXER) if (SONIC_READ(SONIC_TCR) & SONIC_TCR_FU) netif_dbg(lp, tx_err, dev, "%s: tx fifo underrun\n", __func__); - SONIC_WRITE(SONIC_ISR, SONIC_INT_TXER); /* clear the interrupt */ - } /* bus retry */ if (status & SONIC_INT_BR) { @@ -416,13 +405,8 @@ static irqreturn_t sonic_interrupt(int i /* ... to help debug DMA problems causing endless interrupts. */ /* Bounce the eth interface to turn on the interrupt again. */ SONIC_WRITE(SONIC_IMR, 0); - SONIC_WRITE(SONIC_ISR, SONIC_INT_BR); /* clear the interrupt */ } - /* load CAM done */ - if (status & SONIC_INT_LCD) - SONIC_WRITE(SONIC_ISR, SONIC_INT_LCD); /* clear the interrupt */ - status = SONIC_READ(SONIC_ISR) & SONIC_IMR_DEFAULT; } while (status); Patches currently in stable-queue which might be from fthain@xxxxxxxxxxxxxxxxxxx are queue-5.4/net-sonic-fix-receive-buffer-handling.patch queue-5.4/net-sonic-use-mmio-accessors.patch queue-5.4/net-sonic-prevent-tx-watchdog-timeout.patch queue-5.4/net-sonic-clear-interrupt-flags-immediately.patch queue-5.4/net-sonic-fix-command-register-usage.patch queue-5.4/net-sonic-fix-cam-initialization.patch queue-5.4/net-sonic-fix-interface-error-stats-collection.patch queue-5.4/net-sonic-quiesce-sonic-before-re-initializing-descriptor-memory.patch queue-5.4/net-sonic-add-mutual-exclusion-for-accessing-shared-state.patch queue-5.4/net-sonic-fix-receive-buffer-replenishment.patch queue-5.4/net-sonic-avoid-needless-receive-descriptor-eol-flag-updates.patch queue-5.4/net-sonic-improve-receive-descriptor-status-flag-check.patch