* Add AZX_DCAPS_I915_POWEREWELL on SKL is OK?
@ 2015-03-26 5:40 Yang, Libin
2015-03-26 6:29 ` Takashi Iwai
0 siblings, 1 reply; 3+ messages in thread
From: Yang, Libin @ 2015-03-26 5:40 UTC (permalink / raw
To: Takashi Iwai; +Cc: alsa-devel@alsa-project.org
Hi Takashi,
Is it OK to add AZX_DCAPS_I915_POWEREWELL for SKL in hda_intel.c?
SKL HDA controller is not in powerwell domain. But its
HDMI codec is in the domain. My understanding is if the flag
is added here, it means the controller is in the domain. But I can't
find a good place to add a flag to indicate the HDMI codec need
the power domain.
Regards,
Libin
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: Add AZX_DCAPS_I915_POWEREWELL on SKL is OK?
2015-03-26 5:40 Add AZX_DCAPS_I915_POWEREWELL on SKL is OK? Yang, Libin
@ 2015-03-26 6:29 ` Takashi Iwai
2015-03-26 6:54 ` Yang, Libin
0 siblings, 1 reply; 3+ messages in thread
From: Takashi Iwai @ 2015-03-26 6:29 UTC (permalink / raw
To: Yang, Libin; +Cc: alsa-devel@alsa-project.org
At Thu, 26 Mar 2015 05:40:20 +0000,
Yang, Libin wrote:
>
> Hi Takashi,
>
> Is it OK to add AZX_DCAPS_I915_POWEREWELL for SKL in hda_intel.c?
>
> SKL HDA controller is not in powerwell domain. But its
> HDMI codec is in the domain. My understanding is if the flag
> is added here, it means the controller is in the domain. But I can't
> find a good place to add a flag to indicate the HDMI codec need
> the power domain.
The question is when you need the powerwell enable/disable.
If the powerwell has to be adjusted before *any* HDMI codec access,
we'd need this even at probing the codec. Currently HD-audio
controller driver probes a codec by reading VENDOR_ID parameter of the
root node. This was supposed to work even at codec D3, except for
Intel HDMI controllers.
Now, HDMI codec is on the common bus on SKL. Does this mean that
reading the root node parameter works even without powerwell?
This has to be clarified at first. I asked this in the last meeting,
but it seems still unclear.
If the root node parameter can be read without powerwell, then the
controller doesn't need it. Instead, a similar code needs to be added
in the HDMI codec side. OTOH, if the root parameter reads already
requires the powerwell, then yes, we need to add the DCAPS to the
controller.
Takashi
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: Add AZX_DCAPS_I915_POWEREWELL on SKL is OK?
2015-03-26 6:29 ` Takashi Iwai
@ 2015-03-26 6:54 ` Yang, Libin
0 siblings, 0 replies; 3+ messages in thread
From: Yang, Libin @ 2015-03-26 6:54 UTC (permalink / raw
To: Takashi Iwai; +Cc: alsa-devel@alsa-project.org
Hi Takashi,
> -----Original Message-----
> From: Takashi Iwai [mailto:tiwai@suse.de]
> Sent: Thursday, March 26, 2015 2:29 PM
> To: Yang, Libin
> Cc: alsa-devel@alsa-project.org
> Subject: Re: Add AZX_DCAPS_I915_POWEREWELL on SKL is OK?
>
> At Thu, 26 Mar 2015 05:40:20 +0000,
> Yang, Libin wrote:
> >
> > Hi Takashi,
> >
> > Is it OK to add AZX_DCAPS_I915_POWEREWELL for SKL in hda_intel.c?
> >
> > SKL HDA controller is not in powerwell domain. But its
> > HDMI codec is in the domain. My understanding is if the flag
> > is added here, it means the controller is in the domain. But I can't
> > find a good place to add a flag to indicate the HDMI codec need
> > the power domain.
>
> The question is when you need the powerwell enable/disable.
> If the powerwell has to be adjusted before *any* HDMI codec access,
> we'd need this even at probing the codec. Currently HD-audio
> controller driver probes a codec by reading VENDOR_ID parameter of
> the
> root node. This was supposed to work even at codec D3, except for
> Intel HDMI controllers.
>
> Now, HDMI codec is on the common bus on SKL. Does this mean that
> reading the root node parameter works even without powerwell?
> This has to be clarified at first. I asked this in the last meeting,
> but it seems still unclear.
>
> If the root node parameter can be read without powerwell, then the
> controller doesn't need it. Instead, a similar code needs to be added
> in the HDMI codec side. OTOH, if the root parameter reads already
> requires the powerwell, then yes, we need to add the DCAPS to the
> controller.
>
Thanks. I will confirm with our internal silicon team for your question.
>
> Takashi
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2015-03-26 6:55 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2015-03-26 5:40 Add AZX_DCAPS_I915_POWEREWELL on SKL is OK? Yang, Libin
2015-03-26 6:29 ` Takashi Iwai
2015-03-26 6:54 ` Yang, Libin
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).