On 20/07/2023 15:21, Takashi Iwai wrote:
On Thu, 20 Jul 2023 15:31:46 +0200,
Stefan Binding wrote:
To ensure consistency between the HDA core and the CS35L41 HDA
driver, add a device_link between them. This ensures that the
HDA core will suspend first, and resume second, meaning the
amp driver will not miss any events from the playback hook from
the HDA core during system suspend and resume.
Signed-off-by: Stefan Binding <sbinding@xxxxxxxxxxxxxxxxxxxxx>
---
sound/pci/hda/cs35l41_hda.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/sound/pci/hda/cs35l41_hda.c b/sound/pci/hda/cs35l41_hda.c
index 70aa819cfbd64..175378cdf9dfa 100644
--- a/sound/pci/hda/cs35l41_hda.c
+++ b/sound/pci/hda/cs35l41_hda.c
@@ -1063,6 +1063,7 @@ static int cs35l41_hda_bind(struct device *dev, struct device *master, void *mas
{
struct cs35l41_hda *cs35l41 = dev_get_drvdata(dev);
struct hda_component *comps = master_data;
+ unsigned int sleep_flags;
int ret = 0;
if (!comps || cs35l41->index < 0 || cs35l41->index >= HDA_MAX_COMPONENTS)
@@ -1102,6 +1103,11 @@ static int cs35l41_hda_bind(struct device *dev, struct device *master, void *mas
mutex_unlock(&cs35l41->fw_mutex);
+ sleep_flags = lock_system_sleep();
+ if (!device_link_add(&comps->codec->core.dev, cs35l41->dev, DL_FLAG_STATELESS))
+ dev_warn(dev, "Unable to create device link\n");
+ unlock_system_sleep(sleep_flags);
Is lock_system_sleep() mandatory for device_link_add()? The function
takes its rw lock for the race, I suppose.
I believe this is mandatory, to ensure we don't try to add the device
link during a suspend/resume transition.
Its probably unlikely that that would occur during the component bind,
but just in case.
Thanks,
Stefan
thanks,
Takashi
