Re: ALSA bugs with 2.6.12-rc1

From: Jaroslav Kysela
Date: Mon Apr 04 2005 - 13:44:10 EST


On Mon, 4 Apr 2005, Adrian Bunk wrote:

> On Mon, Apr 04, 2005 at 06:08:43PM +0100, Daniel Drake wrote:
> > David Ford wrote:
> > > It seems that 2.6.12-rc1 introduced an ALSA bug generating an oops for a
> > > null pointer.
> > >
> > > codec_semaphore: semaphore is not ready [0x1][0x300300]
> > > codec_read 0: semaphore is not ready for register 0x2c
> > > Unable to handle kernel NULL pointer dereference at virtual address
> > > 00000000
> > >
> > > This happens on multiple machines, 32b and 64bit. I'll be happy to
> > > provide further information if needed.
> >
> > This only happens when you mismatch your kernel and alsa-lib versions, e.g.
> > running alsa-lib-1.0.9-rc2 with alsa-1.0.8 in-kernel drivers, or possibly
> > vice-versa.
>
> Are you saying the userspace interface of the ALSA kernel drivers has
> incompatible changes between minor versions of ALSA?
>
> If this is true, that's a serious bug.

Nope, but newer alsa-lib use an ALSA timer API feature which was not well
debugged. This oops should be fixed in 2.6.12-rc2 and older libraries will
work with newer kernels as well.

Jaroslav

-----
Jaroslav Kysela <perex@xxxxxxx>
Linux Kernel Sound Maintainer
ALSA Project, SUSE Labs
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/