From 41b7e4c3268d9d2056b9c94cceb386649f7b185b Mon Sep 17 00:00:00 2001 From: Steve Hodgson Date: Wed, 28 Apr 2010 09:28:27 +0000 Subject: [PATCH] sfc: Extend the legacy interrupt workarounds Siena has two problems with legacy interrupts: 1. There is no synchronisation between the ISR read completion, and the interrupt deassert message. 2. A downstream read at the "wrong" moment can return 0, and suppress generating the next interrupt. Falcon should suffer from both of these, and it appears it does. Enable EFX_WORKAROUND_15783 on Falcon as well. Also, when we see queues == 0, ensure we always schedule or rearm every event queue. Signed-off-by: Ben Hutchings Signed-off-by: David S. Miller --- drivers/net/sfc/nic.c | 23 +++++++++-------------- drivers/net/sfc/workarounds.h | 2 +- 2 files changed, 10 insertions(+), 15 deletions(-) diff --git a/drivers/net/sfc/nic.c b/drivers/net/sfc/nic.c index 23738f8..b61674c 100644 --- a/drivers/net/sfc/nic.c +++ b/drivers/net/sfc/nic.c @@ -1356,33 +1356,28 @@ static irqreturn_t efx_legacy_interrupt(int irq, void *dev_id) } result = IRQ_HANDLED; - } else if (EFX_WORKAROUND_15783(efx) && - efx->irq_zero_count++ == 0) { + } else if (EFX_WORKAROUND_15783(efx)) { efx_qword_t *event; - /* Ensure we rearm all event queues */ + /* We can't return IRQ_HANDLED more than once on seeing ISR=0 + * because this might be a shared interrupt. */ + if (efx->irq_zero_count++ == 0) + result = IRQ_HANDLED; + + /* Ensure we schedule or rearm all event queues */ efx_for_each_channel(channel, efx) { event = efx_event(channel, channel->eventq_read_ptr); if (efx_event_present(event)) efx_schedule_channel(channel); + else + efx_nic_eventq_read_ack(channel); } - - result = IRQ_HANDLED; } if (result == IRQ_HANDLED) { efx->last_irq_cpu = raw_smp_processor_id(); EFX_TRACE(efx, "IRQ %d on CPU %d status " EFX_DWORD_FMT "\n", irq, raw_smp_processor_id(), EFX_DWORD_VAL(reg)); - } else if (EFX_WORKAROUND_15783(efx)) { - /* We can't return IRQ_HANDLED more than once on seeing ISR0=0 - * because this might be a shared interrupt, but we do need to - * check the channel every time and preemptively rearm it if - * it's idle. */ - efx_for_each_channel(channel, efx) { - if (!channel->work_pending) - efx_nic_eventq_read_ack(channel); - } } return result; diff --git a/drivers/net/sfc/workarounds.h b/drivers/net/sfc/workarounds.h index acd9c73..518f7fc 100644 --- a/drivers/net/sfc/workarounds.h +++ b/drivers/net/sfc/workarounds.h @@ -37,7 +37,7 @@ /* Truncated IPv4 packets can confuse the TX packet parser */ #define EFX_WORKAROUND_15592 EFX_WORKAROUND_FALCON_AB /* Legacy ISR read can return zero once */ -#define EFX_WORKAROUND_15783 EFX_WORKAROUND_SIENA +#define EFX_WORKAROUND_15783 EFX_WORKAROUND_ALWAYS /* Legacy interrupt storm when interrupt fifo fills */ #define EFX_WORKAROUND_17213 EFX_WORKAROUND_SIENA -- 2.7.4