On Thu, 16 Nov 2017 22:28:17 +0100, VDR User wrote:
What you can try is to bisect like git bisect start -- sound/hda sound/pci/hda git bisect good v4.5 git bisect bad v4.6-rc1
Ok, did more bisect'ing. I had to skip a commit because the compile failed but other than that, this is what I wound up with:
git bisect start '--' 'sound/hda' 'sound/pci/hda' # good: [fe0d128c57bf927a713159f60a18d9f315d4d91d] ALSA: jack: Allow building the jack layer without input device git bisect good fe0d128c57bf927a713159f60a18d9f315d4d91d # bad: [9b3dc8aa3fb1a5f38ca9501f20f6ea4dced10fa0] ALSA: hda - Register chmap obj as priv data instead of codec git bisect bad 9b3dc8aa3fb1a5f38ca9501f20f6ea4dced10fa0 # skip: [d61b04f801e6005182d432ebe4a0211c1d6feadd] Merge branch 'for-linus' into for-next git bisect skip d61b04f801e6005182d432ebe4a0211c1d6feadd # good: [ec75a940b1037e877efd9a5a9e94eab1e464f73b] ALSA: hda - hdmi add wmb barrier for audio component git bisect good ec75a940b1037e877efd9a5a9e94eab1e464f73b # good: [d10a80de04a3a8c0d7c1567cbc0a8d2e1181c10a] ALSA: hda - hdmi_find_pcm_slot return value bug fix git bisect good d10a80de04a3a8c0d7c1567cbc0a8d2e1181c10a # good: [6defb60ae4ffe92c29291ed49695daa255b8f559] Merge branch 'for-linus' into for-next git bisect good 6defb60ae4ffe92c29291ed49695daa255b8f559 # good: [67b90cb84be8fde0e51f71834e15c32fbec08562] ALSA: hda - Create common chmap object git bisect good 67b90cb84be8fde0e51f71834e15c32fbec08562 # first bad commit: [9b3dc8aa3fb1a5f38ca9501f20f6ea4dced10fa0] ALSA: hda - Register chmap obj as priv data instead of codec
9b3dc8aa3fb1a5f38ca9501f20f6ea4dced10fa0 is the first bad commit commit 9b3dc8aa3fb1a5f38ca9501f20f6ea4dced10fa0 Author: Subhransu S. Prusty subhransu.s.prusty@intel.com Date: Fri Mar 4 19:59:47 2016 +0530
ALSA: hda - Register chmap obj as priv data instead of codec With this chmap object is added as private data and new ops are added to access driver specific chmap. Signed-off-by: Subhransu S. Prusty <subhransu.s.prusty@intel.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>:040000 040000 11dc1a68fd79182d4e38c2a7fd73fd699dbd0685 69c05f445bc255fc02441742b091247af99fb177 M include :040000 040000 8946088a30757dfcbc1ea6badbe6ea8366b2b39f 6fcf7ce7986ffd29d3b5686ebe63168713b866ed M sound
Does this sound like it could be where the bug resides?.
Thanks for the effort! Yes, it looks more likely than before.
I created a patch with `git format-patch -1 9b3dc8aa3fb1a5f38ca9501f20f6ea4dced10fa0` and tried to apply it to kernel 4.6-rc1 but I failed. I didn't bother trying to hand-reverse it because it looks like it would just cause breakage. Not sure what to do next here so I'll wait and see what you think..
I guess the bug is at copying the chmap data where calculating the size wrongly. A typical error of sizeof() usage.
The fix would be to correct sizeof(chmap) to ARRAY_SIZE(pcm_chmap). At the commit 9b3dc8aa3fb1a5f3, it's in hdmi_chmap_ctl_get() in patch_hdmi.c, correct like:
- for (i = 0; i < sizeof(chmap); i++) + for (i = 0; i < ARRAY_SIZE(pcm_chmap); i++)
For the latest upstream, the relevant code was moved to sound/hda/hdmi_chmap.c, and the fix would be a patch like below.
Could you check it?
thanks,
Takashi
--- diff --git a/sound/hda/hdmi_chmap.c b/sound/hda/hdmi_chmap.c index 81acc20c2535..f21633cd9b38 100644 --- a/sound/hda/hdmi_chmap.c +++ b/sound/hda/hdmi_chmap.c @@ -746,7 +746,7 @@ static int hdmi_chmap_ctl_get(struct snd_kcontrol *kcontrol, memset(pcm_chmap, 0, sizeof(pcm_chmap)); chmap->ops.get_chmap(chmap->hdac, pcm_idx, pcm_chmap);
- for (i = 0; i < sizeof(chmap); i++) + for (i = 0; i < ARRAY_SIZE(pcm_chmap); i++) ucontrol->value.integer.value[i] = pcm_chmap[i];
return 0;