[alsa-devel] [PATCH 1/2] ALSA: HD-Audio: SKL+: abort probe if DSP is present and Skylake driver selected

[Takashi Iwai]

On Mon, 10 Dec 2018 15:31:08 +0100,
Pierre-Louis Bossart wrote:
> 
> 
> On 12/8/18 1:56 AM, Takashi Iwai wrote:
> > On Sat, 08 Dec 2018 01:00:38 +0100,
> > Pierre-Louis Bossart wrote:
> >> Now that the SST/Skylake driver supports per platform selectors, we
> >> can add logic to automatically select the right driver.
> >>
> >> If the Skylake driver is selected, and the DSP is enable, the legacy
> >> HDaudio driver aborts the probe. This will result in a single driver
> >> probing and remove the need for modprobe blacklists.
> >>
> >> Follow-up patches will add a module parameter to bypass the logic if
> >> this automatic detection fails, or if the Skylake driver is unable to
> >> actually support the platform (firmware authentication, missing
> >> topology file, hardware issue, etc).
> >>
> >> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com>
> >> ---
> >>   sound/pci/hda/Kconfig          | 46 ++++++++++++++++++++++++++++++++++
> >>   sound/pci/hda/hda_controller.h |  2 +-
> >>   sound/pci/hda/hda_intel.c      | 34 +++++++++++++++++++------
> >>   sound/soc/intel/Kconfig        |  6 +++++
> >>   4 files changed, 80 insertions(+), 8 deletions(-)
> >>
> >> diff --git a/sound/pci/hda/Kconfig b/sound/pci/hda/Kconfig
> >> index 4235907b7858..634b7fe6a936 100644
> >> --- a/sound/pci/hda/Kconfig
> >> +++ b/sound/pci/hda/Kconfig
> >> @@ -226,6 +226,52 @@ config SND_HDA_POWER_SAVE_DEFAULT
> >>   	  The default time-out value in seconds for HD-audio automatic
> >>   	  power-save mode.  0 means to disable the power-save mode.
> >>   +if SND_HDA_INTEL
> >> +
> >> +config SND_HDA_INTEL_DISABLE_SKL
> >> +	bool
> >> +	help
> >> +	  This option disables HD-audio legacy for
> >> +	  Skylake machines
> > I'm not sure whether we need the selection of this disablement for
> > each model.  Distros would choose these unlikely, and individual users
> > don't have to select multiple of them but only for their machine's
> > model.  So, in the end, the choice would be either yes or no.
> 
> Ah yes, maybe I wasn't clear. This wasn't intended to be selected by
> the user, but selected when when the SND_SOC_INTEL_KBL or
> SND_SOC_SOF_CNL options are set. See the conditions below.
> 
> The main idea what to only deal with the conflict resolution when we
> indeed have a conflict. I also introduced this option on the
> sound/pci/hda side so that SOF can use the same mechanisms, i.e. it's
> the legacy driver doesn't need to know if the conflict happens with
> the SST/Skylake or SOF driver.

OK, that makes sense.

But then better to rephrase the help texts there for avoiding
confusion.  Currently it sounds as if the kconfig always disables the
support of the given chipset.  But the actual behavior is to disable
the binding with the legacy driver *only if* the PCI device class is
declared for Intel DSP.


thanks,

Takashi