ALSA: hda: hdmi - preserve non-MST PCM routing for Intel platforms

Commit 5398e94fb753 ("ALSA: hda - Add DP-MST support for NVIDIA codecs")
introduced a slight change of behaviour how non-MST monitors are
assigned to PCMs on Intel platforms.

In the drm_audio_component.h interface, the third parameter
to pin_eld_notify() is pipe number. On Intel platforms, this value
is -1 for MST. On other platforms, a non-zero pipe id is used to
signal MST use.

This difference leads to some subtle differences in hdmi_find_pcm_slot()
with regards to how non-MST monitors are assigned to PCMs.
This patch restores the original behaviour on Intel platforms while
keeping the new allocation policy on other platforms.

Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Link: https://lore.kernel.org/r/20191129143756.23941-2-kai.vehmanen@linux.intel.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
index a50736269584b34ea4231d7db3bfcf19ff84b4a7..0032bba8cc9dc860280463efd6c7e20388867936 100644 (file)
--- a/sound/pci/hda/patch_hdmi.c
+++ b/sound/pci/hda/patch_hdmi.c
@@ -1353,6 +1353,11 @@ static int hdmi_find_pcm_slot(struct hdmi_spec *spec,
                i = spec->num_nids + (per_pin->dev_id - 1);
                if (i < spec->pcm_used && !(test_bit(i, &spec->pcm_bitmap)))
                        return i;
+
+               /* keep legacy assignment for dev_id>0 on Intel platforms */
+               if (spec->intel_hsw_fixup)
+                       if (!test_bit(per_pin->pin_nid_idx, &spec->pcm_bitmap))
+                               return per_pin->pin_nid_idx;
        }
 
        /* have a second try; check the area over num_nids */