cvs commit: src/sys/dev/sound/pcm dsp.c sound.c
netchild at FreeBSD.org
Mon Sep 12 11:33:34 PDT 2005
netchild 2005-09-12 18:33:34 UTC
FreeBSD src repository
sys/dev/sound/pcm dsp.c sound.c
- Fix the locking in dsp.c to prevent a LOR (AFAIK not on the LOR page).
- Remove an assertion in sound.c, it's not needed (and causes a panic now).
From the conversation via mail between glebius and Ariff:
> Well, but which mutex protects now? Do we own anything else
> in pcm_chnalloc()? I see some queue(4) macros in pcm_chnalloc(),
> they should be protected, shouldn't they?
Queue insertion/removal occur during
1) driver loading (which is pretty much single thread /
sequential) or unloading (mutex protected, bail out if there is
any channel with refcount > 0 or busy).
2) vchan_create()/destroy(), (which is *sigh* quite complicated), but
somehow protected by 'master'/parent channel mutex. Other
thread cannot add/remove vchan (or even continue traversing
that queue) unless it can acquire parent channel mutex.
Fix the locking in dsp.c to prevent a LOR (AFAIK not on the LOR page).
Submitted by: Ariff Abdullah <skywizard at MyBSD.org.my>
Tested with: INVARIANTS and DIAGNOSTICS
Tested by: netchild [1,2], David Reid <david at jetnet.co.uk> 
Revision Changes Path
1.84 +3 -3 src/sys/dev/sound/pcm/dsp.c
1.96 +0 -2 src/sys/dev/sound/pcm/sound.c
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