Re: [PATCH 4.19 102/219] ALSA: hda/hdmi - implement mst_no_extra_pcms flag

[Pavel Machek]

Hi!

> From: Kai Vehmanen <kai.vehmanen@xxxxxxxxxxxxxxx>
> 
> [ Upstream commit 2a2edfbbfee47947dd05f5860c66c0e80ee5e09d ]
> 
> To support the DP-MST multiple streams via single connector feature,
> the HDMI driver was extended with the concept of backup PCMs. See
> commit 9152085defb6 ("ALSA: hda - add DP MST audio support").
...
> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

This variable is not ever set in this patch, nor is it set elsewhere
in 4.19-stable. This means this patch is not suitable for stable.

Best regards,
								Pavel

> index 2003403ce1c8..199927694aef 100644
> --- a/sound/pci/hda/hda_codec.h
> +++ b/sound/pci/hda/hda_codec.h
> @@ -262,6 +262,7 @@ struct hda_codec {
>  	unsigned int force_pin_prefix:1; /* Add location prefix */
>  	unsigned int link_down_at_suspend:1; /* link down at runtime suspend */
>  	unsigned int relaxed_resume:1;	/* don't resume forcibly for jack */
> +	unsigned int mst_no_extra_pcms:1; /* no backup PCMs for DP-MST */
>  
>  #ifdef CONFIG_PM
>  	unsigned long power_on_acct;
> diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
> index c827a2a89cc3..9d5e3c8d62b9 100644
> --- a/sound/pci/hda/patch_hdmi.c
> +++ b/sound/pci/hda/patch_hdmi.c
> @@ -2063,15 +2063,24 @@ static bool is_hdmi_pcm_attached(struct hdac_device *hdac, int pcm_idx)
>  static int generic_hdmi_build_pcms(struct hda_codec *codec)
>  {
>  	struct hdmi_spec *spec = codec->spec;
> -	int idx;
> +	int idx, pcm_num;
>  
>  	/*
>  	 * for non-mst mode, pcm number is the same as before
> -	 * for DP MST mode, pcm number is (nid number + dev_num - 1)
> -	 *  dev_num is the device entry number in a pin
> -	 *
> +	 * for DP MST mode without extra PCM, pcm number is same
> +	 * for DP MST mode with extra PCMs, pcm number is
> +	 *  (nid number + dev_num - 1)
> +	 * dev_num is the device entry number in a pin
>  	 */
> -	for (idx = 0; idx < spec->num_nids + spec->dev_num - 1; idx++) {
> +
> +	if (codec->mst_no_extra_pcms)
> +		pcm_num = spec->num_nids;
> +	else
> +		pcm_num = spec->num_nids + spec->dev_num - 1;
> +
> +	codec_dbg(codec, "hdmi: pcm_num set to %d\n", pcm_num);
> +
> +	for (idx = 0; idx < pcm_num; idx++) {
>  		struct hda_pcm *info;
>  		struct hda_pcm_stream *pstr;
>  

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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