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>
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 @@
}
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