diff options
| author | Ben Hutchings <bhutchings@solarflare.com> | 2012-10-06 02:35:41 +0400 |
|---|---|---|
| committer | Ben Hutchings <bhutchings@solarflare.com> | 2013-08-21 22:47:23 +0400 |
| commit | d829118705f8213ffeffa4fefa8931dea6b7f016 (patch) | |
| tree | a6e8f3cb560c2e113af0574363cb197b1b938345 /drivers/net/ethernet/sfc/falcon.c | |
| parent | 514bedbc3a07e466b040f76319b8f2a4c7b0c7a4 (diff) | |
| download | linux-d829118705f8213ffeffa4fefa8931dea6b7f016.tar.xz | |
sfc: Rework IRQ enable/disable
There are many problems with the current efx_stop_interrupts() and
efx_start_interrupts():
1. On Siena, it is unsafe to disable the master IRQ enable bit
(DRV_INT_EN_KER) while any IRQ sources are enabled.
2. On EF10 there is no master IRQ enable bit, so we cannot expect to
defer IRQs without tearing down event queues. (Though I don't think
we will need to keep any event queues around while the device is down,
as we do for VFDI on Siena.)
3. synchronize_irq() only waits for a running IRQ handler to finish,
not for any propagation through IRQ controllers. Therefore an IRQ may
still be received and handled after efx_stop_interrupts() returns.
IRQ handlers can then race with channel reallocation.
To fix this:
a. Introduce a software IRQ enable flag. So long as this is clear,
IRQ handlers will only acknowledge IRQs and not touch the channel
structures.
b. Define a new struct efx_msi_context as the context for MSIs. This
is never reallocated and is sufficient to find the software enable
flag and the channel structure. It also includes the channel/IRQ
name, which was previously separated out as it must also not be
reallocated.
c. Split efx_{start,stop}_interrupts() into
efx_{,soft_}_{enable,disable}_interrupts(). The 'soft' functions
don't touch the hardware master enable flag (if it exists) and don't
reinitialise or tear down channels with the keep_eventq flag set.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Diffstat (limited to 'drivers/net/ethernet/sfc/falcon.c')
| -rw-r--r-- | drivers/net/ethernet/sfc/falcon.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/net/ethernet/sfc/falcon.c b/drivers/net/ethernet/sfc/falcon.c index f87710e9f8cd..f8de38243348 100644 --- a/drivers/net/ethernet/sfc/falcon.c +++ b/drivers/net/ethernet/sfc/falcon.c @@ -367,6 +367,9 @@ irqreturn_t falcon_legacy_interrupt_a1(int irq, void *dev_id) "IRQ %d on CPU %d status " EFX_OWORD_FMT "\n", irq, raw_smp_processor_id(), EFX_OWORD_VAL(*int_ker)); + if (!likely(ACCESS_ONCE(efx->irq_soft_enabled))) + return IRQ_HANDLED; + /* Check to see if we have a serious error condition */ syserr = EFX_OWORD_FIELD(*int_ker, FSF_AZ_NET_IVEC_FATAL_INT); if (unlikely(syserr)) |