The commit [63e51fd708f5: ALSA: hda - Don't take unresponsive D3 transition too serious] introduced a conditional fallback behavior to the HD-audio controller depending on the flag set. However, it introduced a silly bug, too, that the flag was evaluated in a reverse way. This resulted in a regression of HD-audio controller driver where it can't go to the fallback mode at communication errors.
Unfortunately (or fortunately?) this didn't come up until recently because the affected code path is an error handling that happens only on an unstable hardware chip. Most of recent chips work stably, thus they didn't hit this problem. Now, we've got a regression report with a VIA chip, and this seems indeed requiring the fallback to the polling mode, and finally the bug was revealed.
The fix is a oneliner to remove the wrong logical NOT in the check. (Lesson learned - be careful about double negation.)
The bug should be backported to stable, but the patch won't be applicable to 3.13 or earlier because of the code splits. The stable fix patches for earlier kernels will be posted later manually.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=94021 Fixes: 63e51fd708f5 ('ALSA: hda - Don't take unresponsive D3 transition too serious') Cc: stable@vger.kernel.org # v3.14+ Signed-off-by: Takashi Iwai tiwai@suse.de --- sound/pci/hda/hda_controller.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/sound/pci/hda/hda_controller.c b/sound/pci/hda/hda_controller.c index a2ce773bdc62..17c2637d842c 100644 --- a/sound/pci/hda/hda_controller.c +++ b/sound/pci/hda/hda_controller.c @@ -1164,7 +1164,7 @@ static unsigned int azx_rirb_get_response(struct hda_bus *bus, } }
- if (!bus->no_response_fallback) + if (bus->no_response_fallback) return -1;
if (!chip->polling_mode && chip->poll_count < 2) {