[alsa-devel] [PATCH] ALSA: hda - not use regmap for vendor verb 0x781 of Intel HDMI codec

[Lin, Mengdong]

> -----Original Message-----
> From: Takashi Iwai [mailto:tiwai at suse.de]
> Sent: Monday, April 13, 2015 7:21 PM
> To: Lin, Mengdong
> Cc: alsa-devel at alsa-project.org
> Subject: Re: [PATCH] ALSA: hda - not use regmap for vendor verb 0x781 of Intel
> HDMI codec
> 
> At Mon, 13 Apr 2015 17:50:43 +0800,
> mengdong.lin at intel.com wrote:
> >
> > From: Mengdong Lin <mengdong.lin at intel.com>
> >
> > For HDMI codec on Haswell/Broadwell/Skylake platforms, the vendor verb
> > 0x781 is used enable DP 1.2 mode as a fixup if BIOS has not done this,
> > in function intel_haswell_fixup_enable_dp12(). Otherwise, the display
> > audio playback will be silent.
> >
> > Although the verb 0x781 is added to vendor verbs array, but
> > snd_hdac_regmap_
> > encode_verb() will translate it to verb 0xf81 and cause regmap_write
> > IO failure because 0xf81 is not in the vendor verb array and so will
> > not be taken as a writable register.
> >
> > So this patch no longer uses regmap for verb 0x781 but directly send
> > this command to enable DP1.2 mode.
> 
> What if just add INTEL_GET_VENDOR_VERB as a vendor verb?

Yes, it should work. hda_reg_write will drop the GET bit. 
I'll have a test tomorrow.

Thanks
Mengdong