Commit 56275036 authored Jul 03, 2020 by Kai Vehmanen Committed by Takashi Iwai Jul 07, 2020

ALSA: hda/hdmi: fix failures at PCM open on Intel ICL and later

When HDMI PCM devices are opened in a specific order, with at least one
HDMI/DP receiver connected, ALSA PCM open fails to -EBUSY on the
connected monitor, on recent Intel platforms (ICL/JSL and newer). While
this is not a typical sequence, at least Pulseaudio does this every time
when it is started, to discover the available PCMs.

The rootcause is an invalid assumption in hdmi_add_pin(), where the
total number of converters is assumed to be known at the time the
function is called. On older Intel platforms this held true, but after
ICL/JSL, the order how pins and converters are in the subnode list as
returned by snd_hda_get_sub_nodes(), was changed. As a result,
information for some converters was not stored to per_pin->mux_nids.
And this means some pins cannot be connected to all converters, and
application instead gets -EBUSY instead at open.

The assumption that converters are always before pins in the subnode
list, is not really a valid one. Fix the problem in hdmi_parse_codec()
by introducing separate loops for discovering converters and pins.

BugLink: https://github.com/thesofproject/linux/issues/1978
BugLink: https://github.com/thesofproject/linux/issues/2216
BugLink: https://github.com/thesofproject/linux/issues/2217

Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Link: https://lore.kernel.org/r/20200703153818.2808592-1-kai.vehmanen@linux.intel.com

Signed-off-by: Takashi Iwai <tiwai@suse.de>

parent ad155712

sound/pci/hda/patch_hdmi.c

+23 −13

Original line number	Diff line number	Diff line
		@@ -1804,33 +1804,43 @@ static int hdmi_add_cvt(struct hda_codec *codec, hda_nid_t cvt_nid)

		static int hdmi_parse_codec(struct hda_codec *codec)
		{
		hda_nid_t nid;
		hda_nid_t start_nid;
		unsigned int caps;
		int i, nodes;

		nodes = snd_hda_get_sub_nodes(codec, codec->core.afg, &nid);
		if (!nid \|\| nodes < 0) {
		nodes = snd_hda_get_sub_nodes(codec, codec->core.afg, &start_nid);
		if (!start_nid \|\| nodes < 0) {
		codec_warn(codec, "HDMI: failed to get afg sub nodes\n");
		return -EINVAL;
		}

		for (i = 0; i < nodes; i++, nid++) {
		unsigned int caps;
		unsigned int type;
		/*
		* hdmi_add_pin() assumes total amount of converters to
		* be known, so first discover all converters
		*/
		for (i = 0; i < nodes; i++) {
		hda_nid_t nid = start_nid + i;

		caps = get_wcaps(codec, nid);
		type = get_wcaps_type(caps);

		if (!(caps & AC_WCAP_DIGITAL))
		continue;

		switch (type) {
		case AC_WID_AUD_OUT:
		if (get_wcaps_type(caps) == AC_WID_AUD_OUT)
		hdmi_add_cvt(codec, nid);
		break;
		case AC_WID_PIN:
		hdmi_add_pin(codec, nid);
		break;
		}

		/* discover audio pins */
		for (i = 0; i < nodes; i++) {
		hda_nid_t nid = start_nid + i;

		caps = get_wcaps(codec, nid);

		if (!(caps & AC_WCAP_DIGITAL))
		continue;

		if (get_wcaps_type(caps) == AC_WID_PIN)
		hdmi_add_pin(codec, nid);
		}

		return 0;