[alsa-devel] [PATCH] ALSA: hda - Fix runtime PM

[Lukas Wunner]

Before commit 3b5b899ca67d ("ALSA: hda: Make use of core codec functions
to sync power state"), hda_set_power_state() returned the response to
the Get Power State verb, a 32-bit unsigned integer whose expected value
is 0x233 after transitioning a codec to D3, and 0x0 after transitioning
it to D0.

The response value is significant because hda_codec_runtime_suspend()
does not clear the codec's bit in the codec_powered bitmask unless the
AC_PWRST_CLK_STOP_OK bit (0x200) is set in the response value.  That in
turn prevents the HDA controller from runtime suspending because
azx_runtime_idle() checks that the codec_powered bitmask is zero.

Since commit 3b5b899ca67d, hda_set_power_state() only returns 0x0 or
0x1, thereby breaking runtime PM for any HDA controller.  That's because
an inline function introduced by the commit returns a bool instead of a
32-bit unsigned int.  The change was likely erroneous and resulted from
copying and pasting snd_hda_check_power_state(), which is immediately
preceding the newly introduced inline function.  Fix it.

Link: https://bugs.freedesktop.org/show_bug.cgi?id=106597
Fixes: 3b5b899ca67d ("ALSA: hda: Make use of core codec functions to sync power state")
Cc: Alex Deucher <alexander.deucher at amd.com>
Cc: Abhijeet Kumar <abhijeet.kumar at intel.com>
Reported-and-tested-by: Gunnar Krüger <taijian at posteo.de>
Signed-off-by: Lukas Wunner <lukas at wunner.de>
---
 sound/pci/hda/hda_local.h | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/sound/pci/hda/hda_local.h b/sound/pci/hda/hda_local.h
index 321e78baa63c..9bd935216c18 100644
--- a/sound/pci/hda/hda_local.h
+++ b/sound/pci/hda/hda_local.h
@@ -622,8 +622,10 @@ snd_hda_check_power_state(struct hda_codec *codec, hda_nid_t nid,
 {
 	return snd_hdac_check_power_state(&codec->core, nid, target_state);
 }
-static inline bool snd_hda_sync_power_state(struct hda_codec *codec,
-			   hda_nid_t nid, unsigned int target_state)
+
+static inline unsigned int snd_hda_sync_power_state(struct hda_codec *codec,
+						    hda_nid_t nid,
+						    unsigned int target_state)
 {
 	return snd_hdac_sync_power_state(&codec->core, nid, target_state);
 }
-- 
2.17.0