[PATCH] ALSA: hda/hdmi: let new platforms assign the pcm slot dynamically

[Hui Wang]

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 at canonical.com>
---
 sound/pci/hda/patch_hdmi.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
index e405be7929e3..379a4d786b3b 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))
@@ -2937,6 +2945,9 @@ static int intel_hsw_common_init(struct hda_codec *codec, hda_nid_t vendor_nid,
 	spec->port_num = port_num;
 	spec->intel_hsw_fixup = true;
 
+	if (port_num > 6)
+		spec->no_fixed_assign = true;
+
 	intel_haswell_enable_all_pins(codec, true);
 	intel_haswell_fixup_enable_dp12(codec);
 
-- 
2.25.1