RE: dev/sound/pcm/sound.h shadows INTR_MPSAFE declaration

From: Yuriy Tsibizov <Yuriy.Tsibizov_at_gfk.ru>
Date: Wed, 7 Apr 2004 10:23:08 +0400
> From: Doug White [mailto:dwhite_at_gumbysoft.com]
> On Tue, 6 Apr 2004, Yuriy Tsibizov wrote:
> 
> > > > Today I've noticied that my driver is marked as Giant-locked:
> > >
> > > Is it actually MPSAFE?  If so, feel free to mark it as such,
> > > although pcm
> > > isn't fully locked yet, so we take no responsibility for 
> any damage
> > > caused :)
> >
> > Some sound drivers in -CURRENT allocate interrupts with INTR_MPSAFE.
> > The problem is that after including dev/sound/pcm/sound.h 
> INTR_MPSAFE no longer equals to 512, but it is set to 0. And 
> if sound driver interrupt was allocated as 
> INTR_TYPE_AV|INTR_MPSAFE it will be marked only as INTR_TYPE_TTY.
> 
> Ever think that might be intentional? :)  I'd poke 
> -multimedia to get the
> sound driver folks, though.
Exactly the same piece of code exist on RELENG_4 branch. I think it was used to allow INTR_MPSAFE|INTR_TYPE_AV inside sound
drivers in 4.x, where INTR_MPSAFE and INTR_TYPE_AV are not defined.

If PCM subsystem in 5.x requires that sound drivers should not mark interrupts as INTR_MPSAFE it can be done in less ambiguous way, like this:

-sound.h-
	/* 
	* PCM subsystem in not fully locked.
	* This should force use of Giant lock for sound drivers
	* even when they claim to be MPSAFE.
	*/

#ifndef I_THINK_THAT_PCM_IS_MPSAFE
#define INTR_MPSAFE	0
#endif
-sound.h-

and remove wrong #ifdef INTR_MPSAFE checks, because INTR_MPSAFE was never defined. On RELENG_4 it can be replaced with 
FreeBSD version check.

Yuriy.
Received on Tue Apr 06 2004 - 21:23:58 UTC

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