[PATCH] ALSA: hda/hdmi: fix race in monitor detection during probe
A race exists between build_pcms() and build_controls() phases of codec setup. Build_pcms() sets up notifier for jack events. If a monitor event is received before build_controls() is run, the initial jack state is lost and never reported via mixer controls.
The problem can be hit at least with SOF as the controller driver. SOF calls snd_hda_codec_build_controls() in its workqueue-based probe and this can be delayed enough to hit the race condition.
Fix the issue by invalidating the per-pin ELD information when build_controls() is called. The existing call to hdmi_present_sense() will update the ELD contents. This ensures initial monitor state is correctly reflected via mixer controls.
BugLink: https://github.com/thesofproject/linux/issues/1687 Signed-off-by: Kai Vehmanen kai.vehmanen@linux.intel.com --- sound/pci/hda/patch_hdmi.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c index 403baca89452..e8f0ae5af3d8 100644 --- a/sound/pci/hda/patch_hdmi.c +++ b/sound/pci/hda/patch_hdmi.c @@ -2194,7 +2194,9 @@ static int generic_hdmi_build_controls(struct hda_codec *codec)
for (pin_idx = 0; pin_idx < spec->num_pins; pin_idx++) { struct hdmi_spec_per_pin *per_pin = get_pin(spec, pin_idx); + struct hdmi_eld *pin_eld = &per_pin->sink_eld;
+ pin_eld->eld_valid = false; hdmi_present_sense(per_pin, 0); }
On Tue, 28 Apr 2020 14:38:36 +0200, Kai Vehmanen wrote:
A race exists between build_pcms() and build_controls() phases of codec setup. Build_pcms() sets up notifier for jack events. If a monitor event is received before build_controls() is run, the initial jack state is lost and never reported via mixer controls.
The problem can be hit at least with SOF as the controller driver. SOF calls snd_hda_codec_build_controls() in its workqueue-based probe and this can be delayed enough to hit the race condition.
Fix the issue by invalidating the per-pin ELD information when build_controls() is called. The existing call to hdmi_present_sense() will update the ELD contents. This ensures initial monitor state is correctly reflected via mixer controls.
BugLink: https://github.com/thesofproject/linux/issues/1687 Signed-off-by: Kai Vehmanen kai.vehmanen@linux.intel.com
Applied, thanks.
Takashi
participants (2)
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Kai Vehmanen
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Takashi Iwai