[pulseaudio-discuss] [PATCH 4/4] alsa-mixer: Add force-hw-volume flag to alsa profile sets

[Colin Guthrie]

'Twas brillig, and David Henningsson at 29/06/11 11:53 did gyre and gimble:
> On 2011-06-28 23:13, Colin Guthrie wrote:
>> PS, while looking into this issue, I found a way to easily recreate the
>> "initial volume issue" I discussed on IRC.
>>
>>   1. Comment out the path_set_unify() call.
>>   2. Use my USB Handset with the Speaker kcontrol (no Master or PCM)
>>   3. Switch between Analog Output and Analog Speakers profiles.
>>
>>
>> When witching from AS ->  AO, the Speaker kcontrol is zeroed+muted. When
>> switching from AO ->  AS, it stays in it's zeroed+muted state until the
>> volume control is touched. I think this is similar behaviour to the
>> initial startup problem.
> 
> Aha, interesting.
> 
>> Of course even with path_set_unify() commented out, the fact I have two
>> ports (one of which now at least works \o/) is bogus. Only Analog
>> Speakers should be present so this still needs to be addressed somehow,
>> but I'm beginning to actually "get" the problem in a bit more depth
>> now :)
> 
> Given your analysis of the problem, you definitely seem to have got
> deeper into it than I have :-) But when scratching my head about this
> problem a while ago, I remember thinking that after having run through
> all the paths, we should remove all paths whose volumes/mutes/enums are
> true *subsets* of another path, because having that path does not
> contribute anything.

Yeah I was thinking along the same lines with regards to a process to
sanitise the paths. Essentially, order the paths by score (I think this
is acceptable as the score should already incorporate info with regards
to which port is "better" - although I'd have to double check) and if
any path is just a subset of a path with a higher score, then just nuke it.


I think I've got a bit of a handle on this now, but probably won't be
able to cook some patches up until later in the week or the weekend.

Co




-- 

Colin Guthrie
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http://colin.guthr.ie/

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