Date: Sat, 23 Apr 2011 06:37:09 +0000 (UTC) From: Adrian Chadd <adrian@FreeBSD.org> To: cvs-src-old@freebsd.org Subject: cvs commit: src/sys/dev/ath if_ath.c src/sys/dev/ath/ath_hal/ar5416 ar5416_interrupts.c Message-ID: <201104230637.p3N6bMcU060411@repoman.freebsd.org>
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adrian 2011-04-23 06:37:09 UTC
FreeBSD src repository
Modified files:
sys/dev/ath if_ath.c
sys/dev/ath/ath_hal/ar5416 ar5416_interrupts.c
Log:
SVN rev 220966 on 2011-04-23 06:37:09Z by adrian
Fix a corner-case of interrupt handling which resulted in potentially
spurious (and fatal) interrupt errors.
One user reported seeing this:
Apr 22 18:04:24 ceres kernel: ar5416GetPendingInterrupts: fatal error,
ISR_RAC 0x0 SYNC_CAUSE 0x2000
SYNC_CAUSE of 0x2000 is AR_INTR_SYNC_LOCAL_TIMEOUT which is a bus timeout;
this shouldn't cause HAL_INT_FATAL to be set.
After checking out ath9k, ath9k_ar9002_hw_get_isr() clears (*masked)
before continuing, regardless of whether any bits in the ISR registers
are set. So if AR_INTR_SYNC_CAUSE is set to something that isn't
treated as fatal, and AR_ISR isn't read or is read and is 0, then
(*masked) wouldn't be cleared. Thus any of the existing bits set
that were passed in would be preserved in the output.
The caller in if_ath - ath_intr() - wasn't setting the masked value
to 0 before calling ath_hal_getisr(), so anything that was present
in that uninitialised variable would be preserved in the case above
of AR_ISR=0, AR_INTR_SYNC_CAUSE != 0; and if the HAL_INT_FATAL bit
was set, a fatal condition would be interpreted and the chip was
reset.
This patch does the following:
* ath_intr() - set masked to 0 before calling ath_hal_getisr();
* ar5416GetPendingInterrupts() - clear (*masked) before processing
continues; so if the interrupt source is AR_INTR_SYNC_CAUSE
and it isn't fatal, the hardware isn't reset via returning
HAL_INT_FATAL.
This doesn't fix any underlying errors which trigger
AR_INTR_SYNC_LOCAL_TIMEOUT - which is a bus timeout of some
sort - so that likely should be further investigated.
Revision Changes Path
1.10 +5 -3 src/sys/dev/ath/ath_hal/ar5416/ar5416_interrupts.c
1.317 +6 -1 src/sys/dev/ath/if_ath.c
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