Resending with the correct Cc to alsa-devel ML... On Mon, 05 Mar 2018 12:55:30 +0100, Takashi Iwai wrote: > > On Sat, 03 Mar 2018 13:06:49 +0100, > René Rebe wrote: > > > > Hi all, > > > > testing some new laptops, I noticed the headphone frequency response was lacking > > bass. First I noticed this in the Lenovo T470s, and later I found this also be the case > > on Surface Pro 2 and 3. The Dell XPS13 may also be affected, but I had to return it > > before I found out the solution on the other machines: > > > > https://www.youtube.com/watch?v=a1YkPtfC4LI > > > > I had not yet sent the patch because a) I was too busy and b) I wanted to review this further. > > > > As the other day I got a Lenovo ideapad 720s to test with exactly the same issue, here is the > > current hacked patch: > > > > https://svn.exactcode.de/t2/trunk/package/base/linux/surface-audio.patch > > > > However, given that all newer realtek codecs that came on my desk are affected, > > maybe there is something wrong with the hda_auto_parser.c - I did not yet fully grasp > > all the logic of that. > > > > As you can see in the patch and video (…) the problem is the signal routing of NID 0x15 > > or 0x21 (depending whether it is an older, or newer codec). This is the headphone out, > > and as far as I can see the auto_parser assigned the index 0 pcm output (NID 0x0c) > > which result in this filtered frequency response, likely intended for the laptop’s speakers? > > Using the next NID (I guess that was 0xd?) results in a full frequency response and at > > least to my ears is immediately hearable and obvious. > > > > Without this fixed routing the headphone sounds like a PC speaker in a coke can. > > > > So the question for the authors and HDA experts: Can this be fixed in the auto_parser, > > or is my patch (which btw. has to small unrelated cleanups) modulo potentially some > > renaming of the enum and function, now that more than the Surface is affected, the > > way to go? If this can be fixed more generally I would be happy to hear! > > Could you give the output of alsa-info.sh? We need to check the > details of the codec topology. > > In general, the right approach is to fix at parsing the routing, not > fiddling with the codec routing dynamically at initialization. > > Currently the easy fix would be to provide the fixed DAC connection > list. Maybe we can enhance the generic parser to receive some hints > for DAC selection. The routes are determined by calculating "badness" > values per route, so in theory, we can give some badness values > depending on the target pin type (headphone, speaker, etc). > > > thanks, > > Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
