Hey,
On 2023-07-19 08:01, Takashi Iwai wrote:
On Tue, 18 Jul 2023 19:04:41 +0200,
Kai Vehmanen wrote:
diff --git a/sound/soc/sof/intel/hda-codec.c b/sound/soc/sof/intel/hda-codec.c
index f1fd5b44aaac9..344b61576c0e3 100644
--- a/sound/soc/sof/intel/hda-codec.c
+++ b/sound/soc/sof/intel/hda-codec.c
@@ -415,7 +415,7 @@ int hda_codec_i915_init(struct snd_sof_dev *sdev)
return 0;
/* i915 exposes a HDA codec for HDMI audio */
- ret = snd_hdac_i915_init(bus, true);
+ ret = snd_hdac_i915_init(bus, false);
if (ret < 0)
return ret;
My only bigger concern is corner cases where the display PCI device is on
the bus and visible to kernel, but for some reason there is no working
driver in the system or it is disabled.
With this patch, not having a workign display driver means that there is
also no audio in the system as the SOF driver will never get probed.
In current mainline, one will get the 60sec timeout warning and then
audio driver will proceed to probe and you'll have audio support (minus
HDMI/DP).
Yeah, that was a concern in the past, too. e.g. when you pass
"nomodeset" boot option, the driver will become unusable, even if the
bus is used generically for both analog and HDMI codecs.
Yeah, I have no answer for this. My guess is that in an ideal world, the optional features
related to HDMI outputs would be put in a separate sub-driver, which could -EPROBE_DEFER.
Only when this driver loads, features related to display will work, but the main audio driver
could still load.
This is mostly an issue with very new hardware (e.g. hw is still
behind force_probe flag in xe/i915 driver), but we've had some odd
cases with e.g. systems with both Intel IGFX and other vendors' DGPU.
Audio drivers see the Intel VGA controller in system and will
call snd_hdac_i915_init(), but the audio component bind will never
succeed if the the Intel IGFX is not in actual use.
Will need a bit of time to think about possible scenarios. Possibly this
is not an issue outside early development systems. In theory if IGFX is
disabled in BIOS, and not visible to OS, we are good, and if it's visible,
the i915/xe driver should be loaded, so we are good again.
The 60 seconds timeout is a thing "better than complete disablement",
so it's not ideal, either. Maybe we can add something like the
following:
- Check when the deferred probe takes too long, and warn it
- Provide some runtime option to disable the component binding, so
that user can work around it if needed
A module option to snd_hdac_i915_init would probably be the least of all
evils here.
I see the removal of the 60 second timeout as a good thing regardless.
:-) Usually when nomodeset is used, it's just for safe mode.
With the addition of the xe driver, blindly modprobing i915 will fall
apart regardless.
~Maarten
