We've got a regression report that the recording on Mac with a cirrus codec doesn't work any longer. This turned out to be the missing power up to D0 by power_save_node enablement.

After analyzing the traces, we found out that the culprit is that the codec advertises the "actual" power state of a few nodes to be D0 while the "target" power state is D3. This inconsistency is usually OK, as it implies the power transition. But in the case of cirrus codec, this seems to be stuck to D3 while it's not actually D0.

This patch addresses the issue by checking the power state difference more strictly. It sends the power-state change verb unless both the target and the actual power states show the given value.

We may introduce yet another flag indicating the possible broken hardware power state, but it's anyway safer to set the proper power state even in a transition (at least it's harmless as long as the target state is same). So this simpler change was applied now.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=116171 Cc: stable@vger.kernel.org # v4.4+ Signed-off-by: Takashi Iwai tiwai@suse.de --- sound/pci/hda/hda_generic.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/sound/pci/hda/hda_generic.c b/sound/pci/hda/hda_generic.c index 7ca5b89f088a..dfaf1a93fb8a 100644 --- a/sound/pci/hda/hda_generic.c +++ b/sound/pci/hda/hda_generic.c @@ -826,7 +826,7 @@ static hda_nid_t path_power_update(struct hda_codec *codec, bool allow_powerdown) { hda_nid_t nid, changed = 0; - int i, state; + int i, state, power;

for (i = 0; i < path->depth; i++) { nid = path->path[i]; @@ -838,7 +838,9 @@ static hda_nid_t path_power_update(struct hda_codec *codec, state = AC_PWRST_D0; else state = AC_PWRST_D3; - if (!snd_hda_check_power_state(codec, nid, state)) { + power = snd_hda_codec_read(codec, nid, 0, + AC_VERB_GET_POWER_STATE, 0); + if (power != (state | (state << 4))) { snd_hda_codec_write(codec, nid, 0, AC_VERB_SET_POWER_STATE, state); changed = nid;