[LAU] mute laptop speakers with Intel HDA

[Takashi Iwai]

At Tue, 07 Aug 2007 14:45:12 +0200,
I wrote:
> 
> At Mon, 6 Aug 2007 21:58:29 +0200,
> Fons Adriaensen wrote:
> > 
> > On Mon, Aug 06, 2007 at 07:13:12PM +0200, Takashi Iwai wrote:
> > 
> > > Then, well, you made it really too dramatic.  Requesting the update to
> > > the latest kernel is a very standard procedure.  Otherwise, the
> > > developer cannot start real debugging at all.
> > 
> > Not being a kernel/driver specialist at all, I do have some 
> > difficulty in believing this.
> > 
> > The kernel has to call some routines in the driver, and provide
> > some services to it. I find it difficult to imagine
> > 
> > - how a kernel bug could affect just one driver and have no 
> >   impact on all the others.
> 
> A "kernel bug" is too generic wording.  In most cases, it's a bug in
> other components that a driver depends on.  For example, the kernel
> memory management, scheduler, ACPI, IRQ handler, etc. are involved
> with the sound driver.  If one of them is broken, the driver doesn't
> work.

... well, to be a bit more specific, suppose the case of a wrong IRQ
assignment.  ACPI has many built-in quirks as workaround of broken
BIOS.  It might be your device.  It might be fixed in the later
release.
The PCI core code change may influence.  Possibly the default IRQ
routing is changed for your device, which you needed a special boot
option.
Or, the driver using MSI may behave utterly differently depending on
the kernel version because of the core MSI implementation. 

It's more or less a same problem from the user-space, "wrong IRQ".
But, the cause can vary indeed.


Takashi