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authorSteve Hodgson <shodgson@solarflare.com>2010-04-28 13:28:27 +0400
committerDavid S. Miller <davem@davemloft.net>2010-04-28 23:44:35 +0400
commit41b7e4c3268d9d2056b9c94cceb386649f7b185b (patch)
tree706d46fdd10943ba86d4eda2ff210bc506997144
parentb7b40eeb0f76e73503a7e5a98d1353c2e42d9a18 (diff)
downloadlinux-41b7e4c3268d9d2056b9c94cceb386649f7b185b.tar.xz
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 <bhutchings@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/sfc/nic.c23
-rw-r--r--drivers/net/sfc/workarounds.h2
2 files changed, 10 insertions, 15 deletions
diff --git a/drivers/net/sfc/nic.c b/drivers/net/sfc/nic.c
index 23738f80835b..b61674cb0c19 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 acd9c734e483..518f7fc91473 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