If the platform set the dyn_pcm_assign to true, it will call hdmi_find_pcm_slot() to find a pcm slot when hdmi/dp monitor is connected and need to create a pcm.

So far only intel_hsw_common_init() and patch_nvhdmi() set the dyn_pcm_assign to true, here we let tgl platforms assign the pcm slot dynamically first, if the driver runs for a period of time and there is no regression reported, we could set no_fixed_assgin to true in the intel_hsw_common_init(), and then set it to true in the patch_nvhdmi().

This change comes from the discussion between Takashi and Kai Vehmanen. Please refer to: https://github.com/alsa-project/alsa-lib/pull/118

Signed-off-by: Hui Wang hui.wang@canonical.com --- Did the test with this patch on 2 TGL machines, and with both legacy HDA driver and sof driver, plug 1 monitor into the machine, plug 2 monitors into the machine and plug 2 monitors into a dp-mst hub, they all worked as expcted, the first 2 pcm slots was assigned to monitors, and playback worked well.

sound/pci/hda/patch_hdmi.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c index 97adff0cbcab..1aca815b920d 100644 --- a/sound/pci/hda/patch_hdmi.c +++ b/sound/pci/hda/patch_hdmi.c @@ -157,6 +157,7 @@ struct hdmi_spec {

bool dyn_pin_out; bool dyn_pcm_assign; + bool no_fixed_assign; bool intel_hsw_fixup; /* apply Intel platform-specific fixups */ /* * Non-generic VIA/NVIDIA specific @@ -1345,6 +1346,12 @@ static int hdmi_find_pcm_slot(struct hdmi_spec *spec, { int i;

+ /* on the new machines, try to assign the pcm slot dynamically, + * not use the preferred fixed map anymore. + */ + if (spec->no_fixed_assign) + goto last_try; + /* * generic_hdmi_build_pcms() may allocate extra PCMs on some * platforms (with maximum of 'num_nids + dev_num - 1') @@ -1374,6 +1381,7 @@ static int hdmi_find_pcm_slot(struct hdmi_spec *spec, return i; }

+ last_try: /* the last try; check the empty slots in pins */ for (i = 0; i < spec->num_nids; i++) { if (!test_bit(i, &spec->pcm_bitmap)) @@ -2988,8 +2996,16 @@ static int patch_i915_tgl_hdmi(struct hda_codec *codec) * the index indicate the port number. */ static const int map[] = {0x4, 0x6, 0x8, 0xa, 0xb, 0xc, 0xd, 0xe, 0xf}; + int ret;

- return intel_hsw_common_init(codec, 0x02, map, ARRAY_SIZE(map)); + ret = intel_hsw_common_init(codec, 0x02, map, ARRAY_SIZE(map)); + if (!ret) { + struct hdmi_spec *spec = codec->spec; + + spec->no_fixed_assign = true; + } + + return ret; }

/* Intel Baytrail and Braswell; with eld notifier */