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author | Takashi Iwai <tiwai@suse.de> | 2016-08-04 22:38:36 +0200 |
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committer | Takashi Iwai <tiwai@suse.de> | 2016-08-10 15:05:17 +0200 |
commit | a52ff34e5ec61749c62c6618b76a9d6dbecee450 (patch) | |
tree | 1690217f584b284eb714a7509c3a7f0f9d3bba68 /Documentation/devicetree | |
parent | 41f5e3bdbf706a9e98194bf0c4b62a875c02f170 (diff) |
ALSA: hda - Manage power well properly for resume
For SKL and later Intel chips, we control the power well per codec
basis via link_power callback since the commit [03b135cebc47: ALSA:
hda - remove dependency on i915 power well for SKL].
However, there are a few exceptional cases where the gfx registers are
accessed from the audio driver: namely the wakeup override bit
toggling at (both system and runtime) resume. This seems causing a
kernel warning when accessed during the power well down (and likely
resulting in the bogus register accesses).
This patch puts the proper power up / down sequence around the resume
code so that the wakeup bit is fiddled properly while the power is
up. (The other callback, sync_audio_rate, is used only in the PCM
callback, so it's guaranteed in the power-on.)
Also, by this proper power up/down, the instantaneous flip of wakeup
bit in the resume callback that was introduced by the commit
[033ea349a7cd: ALSA: hda - Fix Skylake codec timeout] becomes
superfluous, as snd_hdac_display_power() already does it. So we can
clean it up together.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=96214
Fixes: 03b135cebc47 ('ALSA: hda - remove dependency on i915 power well for SKL')
Cc: <stable@vger.kernel.org> # v4.2+
Tested-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'Documentation/devicetree')
0 files changed, 0 insertions, 0 deletions