Increasing the DMESG buffer....

Kevin Oberman kob6558 at
Thu Nov 22 22:15:06 UTC 2012

On Thu, Nov 22, 2012 at 2:05 PM, Adrian Chadd <adrian at> wrote:
> On 22 November 2012 06:30, Alexander Motin <mav at> wrote:
>> Neither ICH, nor any other driver I know have amount of information
>> comparable to what HDA hardware provides. So the analogy is not good.
>> Respecting that most CODECs have no published datasheets, that information
>> is the only input for debugging.
>> snd_hda also uses hw.snd.verbose=3. But it is used for even deeper driver
>> debugging. It also enables a lot of debugging in sound(4), that can be too
>> verbose for HDA debugging.
>> I will recheck again how can it be reorganized, but I think that the real
>> problem is not in HDA. We need some way to structure and filter the output.
> I honestly would like to just see it spat out using a userland tool,
> rather than having the kernel print that level of topology data out.
> It's highly unlikely that a topology problem is going to cause a
> system to not boot, right? So the kernel itself doesn't need to be
> able to spit that data out.

Maybe I'm missing something, but the data needed to adjust HDAC is
available from 'sysctl dev.hdaa'. I have not looked at the verbose
output in quite a while, but I think it is mstly or entirely hte
information in that and 'sysctl dev.hdac'. I never needed to look
elsewhere to get mine set up properly.

Also, isn't the entire verbose boot captured in /var/run/dmesg?
R. Kevin Oberman, Network Engineer
E-mail: kob6558 at

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