[PATCH v2 00/11] Fix support for System Suspend for CS35L41 HDA

Stefan Binding
2023-07-21T15:19:38Z

There have been a couple of customer reports of intermittant issues after
system resume, where sometimes the DSP firmware stops responding.
Investigations into this issue show that there is a race between receiving
a prepare from the HDA core, and the firmware reload which is started by
the system resume. This can causes the Global Enable on the CS35L41 to be
enabled during the firmware load, which can sometimes cause issues in the
DSP.

The existing system resume behaviour also did not resume the audio, if
audio was previously playing when it was suspended.
In addition, during investigation, it was found there were additional
problems in the System Resume sequence, as well as the Playback sequence
with External Boost, where the driver does not correctly follow its
enable sequence for this mode. This can cause additional issues such as
pops and clicks.

This chain intends to correct the sequences for playback and system
suspend/resume so that the driver: obeys the external boost enable sequence;
resumes audio on system resume; and avoids the race condition on firmware
load and playback during system resume.

Changes since v1:
- Split patch 1 into 2 separate patches
- Combine Patches 6 and 9

Stefan Binding (11):
ALSA: cs35l41: Use mbox command to enable speaker output for external
boost
ALSA: cs35l41: Poll for Power Up/Down rather than waiting a fixed
delay
ALSA: hda: cs35l41: Check mailbox status of pause command after
firmware load
ALSA: hda: cs35l41: Ensure we correctly re-sync regmap before system
suspending.
ALSA: hda: cs35l41: Ensure we pass up any errors during system
suspend.
ALSA: hda: cs35l41: Move Play and Pause into separate functions
ALSA: hda: hda_component: Add pre and post playback hooks to
hda_component
ALSA: hda: cs35l41: Use pre and post playback hooks
ALSA: hda: cs35l41: Rework System Suspend to ensure correct call
separation
ALSA: hda: cs35l41: Add device_link between HDA and cs35l41_hda
ALSA: hda: cs35l41: Ensure amp is only unmuted during playback

include/sound/cs35l41.h | 5 +-
sound/pci/hda/cs35l41_hda.c | 288 +++++++++++++++++++++++++--------
sound/pci/hda/hda_component.h | 2 +
sound/pci/hda/patch_realtek.c | 10 +-
sound/soc/codecs/cs35l41-lib.c | 118 ++++++++++++--
sound/soc/codecs/cs35l41.c | 18 +--
6 files changed, 343 insertions(+), 98 deletions(-)

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2.34.1