From 78c29bd95bd8d2c3bcf7932cb3ab8ae01cd8f58f Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 2 Jul 2009 04:04:45 +0000 Subject: [PATCH] forcedeth: Fix NAPI race. MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Eric Dumazet a écrit : > Ingo Molnar a écrit : >>> The following changes since commit 52989765629e7d182b4f146050ebba0abf2cb0b7: >>> Linus Torvalds (1): >>> Merge git://git.kernel.org/.../davem/net-2.6 >>> >>> are available in the git repository at: >>> >>> master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6.git master >> Hm, something in this lot quickly wrecked networking here - see the >> tx timeout dump below. It starts with: >> >> [ 351.004596] WARNING: at net/sched/sch_generic.c:246 dev_watchdog+0x10b/0x19c() >> [ 351.011815] Hardware name: System Product Name >> [ 351.016220] NETDEV WATCHDOG: eth0 (forcedeth): transmit queue 0 timed out >> >> Config attached. Unfortunately i've got no time to do bisection >> today. > > > > forcedeth might have a problem, in its netif_wake_queue() logic, but > I could not see why a recent patch could make this problem visible now. > > CPU0/1: AMD Athlon(tm) 64 X2 Dual Core Processor 3800+ stepping 02 > is not a new cpu either :) > > forcedeth uses an internal tx_stop without appropriate barrier. > > Could you try following patch ? > > (random guess as I dont have much time right now) We might have a race in napi_schedule(), leaving interrupts disabled forever. I cannot test this patch, I dont have the hardware... Tested-by: Ingo Molnar Signed-off-by: David S. Miller --- drivers/net/forcedeth.c | 25 ++++++++++++++----------- 1 file changed, 14 insertions(+), 11 deletions(-) diff --git a/drivers/net/forcedeth.c b/drivers/net/forcedeth.c index 1094d292630f..3b4e0766c7b2 100644 --- a/drivers/net/forcedeth.c +++ b/drivers/net/forcedeth.c @@ -3514,11 +3514,13 @@ static irqreturn_t nv_nic_irq(int foo, void *data) nv_msi_workaround(np); #ifdef CONFIG_FORCEDETH_NAPI - napi_schedule(&np->napi); - - /* Disable furthur irq's - (msix not enabled with napi) */ - writel(0, base + NvRegIrqMask); + if (napi_schedule_prep(&np->napi)) { + /* + * Disable further irq's (msix not enabled with napi) + */ + writel(0, base + NvRegIrqMask); + __napi_schedule(&np->napi); + } #else do @@ -3615,12 +3617,13 @@ static irqreturn_t nv_nic_irq_optimized(int foo, void *data) nv_msi_workaround(np); #ifdef CONFIG_FORCEDETH_NAPI - napi_schedule(&np->napi); - - /* Disable furthur irq's - (msix not enabled with napi) */ - writel(0, base + NvRegIrqMask); - + if (napi_schedule_prep(&np->napi)) { + /* + * Disable further irq's (msix not enabled with napi) + */ + writel(0, base + NvRegIrqMask); + __napi_schedule(&np->napi); + } #else do { -- 2.20.1