Skip to content

Commit

Permalink
ALSA: hda: Fix headset detection failure due to unstable sort
Browse files Browse the repository at this point in the history
The auto_parser assumed sort() was stable, but the kernel's sort() uses
heapsort, which has never been stable. After commit 0e02ca2
("lib/sort: optimize heapsort with double-pop variation"), the order of
equal elements changed, causing the headset to fail to work.

Fix the issue by recording the original order of elements before
sorting and using it as a tiebreaker for equal elements in the
comparison function.

Fixes: b9030a0 ("ALSA: hda - Use standard sort function in hda_auto_parser.c")
Reported-by: Austrum <austrum.lab@gmail.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219158
Tested-by: Austrum <austrum.lab@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Link: https://patch.msgid.link/20250128165415.643223-1-visitorckw@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
  • Loading branch information
Kuan-Wei Chiu authored and Takashi Iwai committed Jan 28, 2025
1 parent 519b2b1 commit 3b43095
Showing 2 changed files with 8 additions and 1 deletion.
8 changes: 7 additions & 1 deletion sound/pci/hda/hda_auto_parser.c
Original file line number Diff line number Diff line change
@@ -80,7 +80,11 @@ static int compare_input_type(const void *ap, const void *bp)

/* In case one has boost and the other one has not,
pick the one with boost first. */
return (int)(b->has_boost_on_pin - a->has_boost_on_pin);
if (a->has_boost_on_pin != b->has_boost_on_pin)
return (int)(b->has_boost_on_pin - a->has_boost_on_pin);

/* Keep the original order */
return a->order - b->order;
}

/* Reorder the surround channels
@@ -400,6 +404,8 @@ int snd_hda_parse_pin_defcfg(struct hda_codec *codec,
reorder_outputs(cfg->speaker_outs, cfg->speaker_pins);

/* sort inputs in the order of AUTO_PIN_* type */
for (i = 0; i < cfg->num_inputs; i++)
cfg->inputs[i].order = i;
sort(cfg->inputs, cfg->num_inputs, sizeof(cfg->inputs[0]),
compare_input_type, NULL);

1 change: 1 addition & 0 deletions sound/pci/hda/hda_auto_parser.h
Original file line number Diff line number Diff line change
@@ -37,6 +37,7 @@ struct auto_pin_cfg_item {
unsigned int is_headset_mic:1;
unsigned int is_headphone_mic:1; /* Mic-only in headphone jack */
unsigned int has_boost_on_pin:1;
int order;
};

struct auto_pin_cfg;

0 comments on commit 3b43095

Please sign in to comment.