[PATCH v5 0/5] Make HDMI ELD usable for hotplug

[PATCH v5 0/5] Make HDMI ELD usable for hotplug

[David Henningsson]

Just more fixups according to Takashi's comments.

David Henningsson (5):
  ALSA: hda - hdmi: ELD shouldn't be valid after unplug
  ALSA: hda - hdmi: Do not expose eld data when eld is invalid
  ALSA: hda - hdmi: Refactor hdmi_eld into parsed_hdmi_eld
  ALSA: hda - hdmi: Protect ELD buffer
  ALSA: hda - hdmi: Notify userspace when ELD control changes

 sound/pci/hda/hda_eld.c    |   52 +++++++++++-----------
 sound/pci/hda/hda_local.h  |   28 +++++++-----
 sound/pci/hda/patch_hdmi.c |  105 ++++++++++++++++++++++++++++++++++----------
 3 files changed, 127 insertions(+), 58 deletions(-)

-- 
1.7.9.5

[PATCH v5 1/5] ALSA: hda - hdmi: ELD shouldn't be valid after unplug

[David Henningsson]

Currently, eld_valid is never set to false, except at kernel module
load time. This patch makes sure that eld is no longer valid when
the cable is (hot-)unplugged.

Cc: stable@kernel.org
Signed-off-by: David Henningsson <david.henningsson@canonical.com>
---
 sound/pci/hda/patch_hdmi.c |    1 +
 1 file changed, 1 insertion(+)

diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
index b9af281b..32adaa6 100644
--- a/sound/pci/hda/patch_hdmi.c
+++ b/sound/pci/hda/patch_hdmi.c
@@ -1176,6 +1176,7 @@ static void hdmi_present_sense(struct hdmi_spec_per_pin *per_pin, int repoll)
 		"HDMI status: Codec=%d Pin=%d Presence_Detect=%d ELD_Valid=%d\n",
 		codec->addr, pin_nid, eld->monitor_present, eld_valid);
 
+	eld->eld_valid = false;
 	if (eld_valid) {
 		if (!snd_hdmi_get_eld(eld, codec, pin_nid))
 			snd_hdmi_show_eld(eld);
-- 
1.7.9.5

[PATCH v5 2/5] ALSA: hda - hdmi: Do not expose eld data when eld is invalid

[David Henningsson]

Previously, it was possible to read the eld data of the previous
monitor connected. This should not be allowed.

Also refactor the function slightly.

Signed-off-by: David Henningsson <david.henningsson@canonical.com>
---
 sound/pci/hda/patch_hdmi.c |   25 ++++++++++++++++++-------
 1 file changed, 18 insertions(+), 7 deletions(-)

diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
index 32adaa6..6bcdd66 100644
--- a/sound/pci/hda/patch_hdmi.c
+++ b/sound/pci/hda/patch_hdmi.c
@@ -343,14 +343,16 @@ static int hdmi_eld_ctl_info(struct snd_kcontrol *kcontrol,
 			struct snd_ctl_elem_info *uinfo)
 {
 	struct hda_codec *codec = snd_kcontrol_chip(kcontrol);
-	struct hdmi_spec *spec;
+	struct hdmi_spec *spec = codec->spec;
+	struct hdmi_eld *eld;
 	int pin_idx;
 
-	spec = codec->spec;
 	uinfo->type = SNDRV_CTL_ELEM_TYPE_BYTES;
 
 	pin_idx = kcontrol->private_value;
-	uinfo->count = spec->pins[pin_idx].sink_eld.eld_size;
+	eld = &spec->pins[pin_idx].sink_eld;
+
+	uinfo->count = eld->eld_valid ? eld->eld_size : 0;
 
 	return 0;
 }
@@ -359,14 +361,23 @@ static int hdmi_eld_ctl_get(struct snd_kcontrol *kcontrol,
 			struct snd_ctl_elem_value *ucontrol)
 {
 	struct hda_codec *codec = snd_kcontrol_chip(kcontrol);
-	struct hdmi_spec *spec;
+	struct hdmi_spec *spec = codec->spec;
+	struct hdmi_eld *eld;
 	int pin_idx;
 
-	spec = codec->spec;
 	pin_idx = kcontrol->private_value;
+	eld = &spec->pins[pin_idx].sink_eld;
+
+	if (eld->eld_size > ARRAY_SIZE(ucontrol->value.bytes.data)) {
+		snd_BUG();
+		return -EINVAL;
+	}
 
-	memcpy(ucontrol->value.bytes.data,
-		spec->pins[pin_idx].sink_eld.eld_buffer, ELD_MAX_SIZE);
+	memset(ucontrol->value.bytes.data, 0,
+	       ARRAY_SIZE(ucontrol->value.bytes.data));
+	if (eld->eld_valid)
+		memcpy(ucontrol->value.bytes.data, eld->eld_buffer,
+		       eld->eld_size);
 
 	return 0;
 }
-- 
1.7.9.5

[PATCH v5 3/5] ALSA: hda - hdmi: Refactor hdmi_eld into parsed_hdmi_eld

[David Henningsson]

For better readability, the information that is parsed out of the
ELD data is now put into a separate parsed_hdmi_eld struct.

Signed-off-by: David Henningsson <david.henningsson@canonical.com>
---
 sound/pci/hda/hda_eld.c    |   46 ++++++++++++++++++++------------------------
 sound/pci/hda/hda_local.h  |   27 ++++++++++++++++----------
 sound/pci/hda/patch_hdmi.c |   28 ++++++++++++++++++---------
 3 files changed, 57 insertions(+), 44 deletions(-)

diff --git a/sound/pci/hda/hda_eld.c b/sound/pci/hda/hda_eld.c
index 4c054f4..16066d7 100644
--- a/sound/pci/hda/hda_eld.c
+++ b/sound/pci/hda/hda_eld.c
@@ -246,8 +246,8 @@ static void hdmi_update_short_audio_desc(struct cea_sad *a,
 /*
  * Be careful, ELD buf could be totally rubbish!
  */
-static int hdmi_update_eld(struct hdmi_eld *e,
-			   const unsigned char *buf, int size)
+int snd_hdmi_parse_eld(struct parsed_hdmi_eld *e,
+			  const unsigned char *buf, int size)
 {
 	int mnl;
 	int i;
@@ -260,7 +260,6 @@ static int hdmi_update_eld(struct hdmi_eld *e,
 		goto out_fail;
 	}
 
-	e->eld_size = size;
 	e->baseline_len = GRAB_BITS(buf, 2, 0, 8);
 	mnl		= GRAB_BITS(buf, 4, 0, 5);
 	e->cea_edid_ver	= GRAB_BITS(buf, 4, 5, 3);
@@ -305,7 +304,6 @@ static int hdmi_update_eld(struct hdmi_eld *e,
 	if (!e->spk_alloc)
 		e->spk_alloc = 0xffff;
 
-	e->eld_valid = true;
 	return 0;
 
 out_fail:
@@ -318,17 +316,16 @@ int snd_hdmi_get_eld_size(struct hda_codec *codec, hda_nid_t nid)
 						 AC_DIPSIZE_ELD_BUF);
 }
 
-int snd_hdmi_get_eld(struct hdmi_eld *eld,
-		     struct hda_codec *codec, hda_nid_t nid)
+int snd_hdmi_get_eld(struct hda_codec *codec, hda_nid_t nid,
+		     unsigned char *buf, int *eld_size)
 {
 	int i;
 	int ret;
 	int size;
-	unsigned char *buf;
 
 	/*
 	 * ELD size is initialized to zero in caller function. If no errors and
-	 * ELD is valid, actual eld_size is assigned in hdmi_update_eld()
+	 * ELD is valid, actual eld_size is assigned.
 	 */
 
 	size = snd_hdmi_get_eld_size(codec, nid);
@@ -343,8 +340,6 @@ int snd_hdmi_get_eld(struct hdmi_eld *eld,
 	}
 
 	/* set ELD buffer */
-	buf = eld->eld_buffer;
-
 	for (i = 0; i < size; i++) {
 		unsigned int val = hdmi_get_eld_data(codec, nid, i);
 		/*
@@ -372,8 +367,7 @@ int snd_hdmi_get_eld(struct hdmi_eld *eld,
 		buf[i] = val;
 	}
 
-	ret = hdmi_update_eld(eld, buf, size);
-
+	*eld_size = size;
 error:
 	return ret;
 }
@@ -438,7 +432,7 @@ void snd_print_channel_allocation(int spk_alloc, char *buf, int buflen)
 	buf[j] = '\0';	/* necessary when j == 0 */
 }
 
-void snd_hdmi_show_eld(struct hdmi_eld *e)
+void snd_hdmi_show_eld(struct parsed_hdmi_eld *e)
 {
 	int i;
 
@@ -487,10 +481,11 @@ static void hdmi_print_sad_info(int i, struct cea_sad *a,
 static void hdmi_print_eld_info(struct snd_info_entry *entry,
 				struct snd_info_buffer *buffer)
 {
-	struct hdmi_eld *e = entry->private_data;
+	struct hdmi_eld *eld = entry->private_data;
+	struct parsed_hdmi_eld *e = &eld->info;
 	char buf[SND_PRINT_CHANNEL_ALLOCATION_ADVISED_BUFSIZE];
 	int i;
-	static char *eld_versoin_names[32] = {
+	static char *eld_version_names[32] = {
 		"reserved",
 		"reserved",
 		"CEA-861D or below",
@@ -505,15 +500,15 @@ static void hdmi_print_eld_info(struct snd_info_entry *entry,
 		[4 ... 7] = "reserved"
 	};
 
-	snd_iprintf(buffer, "monitor_present\t\t%d\n", e->monitor_present);
-	snd_iprintf(buffer, "eld_valid\t\t%d\n", e->eld_valid);
-	if (!e->eld_valid)
+	snd_iprintf(buffer, "monitor_present\t\t%d\n", eld->monitor_present);
+	snd_iprintf(buffer, "eld_valid\t\t%d\n", eld->eld_valid);
+	if (!eld->eld_valid)
 		return;
 	snd_iprintf(buffer, "monitor_name\t\t%s\n", e->monitor_name);
 	snd_iprintf(buffer, "connection_type\t\t%s\n",
 				eld_connection_type_names[e->conn_type]);
 	snd_iprintf(buffer, "eld_version\t\t[0x%x] %s\n", e->eld_ver,
-					eld_versoin_names[e->eld_ver]);
+					eld_version_names[e->eld_ver]);
 	snd_iprintf(buffer, "edid_version\t\t[0x%x] %s\n", e->cea_edid_ver,
 				cea_edid_version_names[e->cea_edid_ver]);
 	snd_iprintf(buffer, "manufacture_id\t\t0x%x\n", e->manufacture_id);
@@ -535,7 +530,8 @@ static void hdmi_print_eld_info(struct snd_info_entry *entry,
 static void hdmi_write_eld_info(struct snd_info_entry *entry,
 				struct snd_info_buffer *buffer)
 {
-	struct hdmi_eld *e = entry->private_data;
+	struct hdmi_eld *eld = entry->private_data;
+	struct parsed_hdmi_eld *e = &eld->info;
 	char line[64];
 	char name[64];
 	char *sname;
@@ -551,9 +547,9 @@ static void hdmi_write_eld_info(struct snd_info_entry *entry,
 		 * 	eld_version edid_version
 		 */
 		if (!strcmp(name, "monitor_present"))
-			e->monitor_present = val;
+			eld->monitor_present = val;
 		else if (!strcmp(name, "eld_valid"))
-			e->eld_valid = val;
+			eld->eld_valid = val;
 		else if (!strcmp(name, "connection_type"))
 			e->conn_type = val;
 		else if (!strcmp(name, "port_id"))
@@ -627,7 +623,7 @@ void snd_hda_eld_proc_free(struct hda_codec *codec, struct hdmi_eld *eld)
 #endif /* CONFIG_PROC_FS */
 
 /* update PCM info based on ELD */
-void snd_hdmi_eld_update_pcm_info(struct hdmi_eld *eld,
+void snd_hdmi_eld_update_pcm_info(struct parsed_hdmi_eld *e,
 			      struct hda_pcm_stream *hinfo)
 {
 	u32 rates;
@@ -644,8 +640,8 @@ void snd_hdmi_eld_update_pcm_info(struct hdmi_eld *eld,
 	formats = SNDRV_PCM_FMTBIT_S16_LE;
 	maxbps = 16;
 	channels_max = 2;
-	for (i = 0; i < eld->sad_count; i++) {
-		struct cea_sad *a = &eld->sad[i];
+	for (i = 0; i < e->sad_count; i++) {
+		struct cea_sad *a = &e->sad[i];
 		rates |= a->rates;
 		if (a->channels > channels_max)
 			channels_max = a->channels;
diff --git a/sound/pci/hda/hda_local.h b/sound/pci/hda/hda_local.h
index 05f1d59..363cd48 100644
--- a/sound/pci/hda/hda_local.h
+++ b/sound/pci/hda/hda_local.h
@@ -713,10 +713,10 @@ struct cea_sad {
 /*
  * ELD: EDID Like Data
  */
-struct hdmi_eld {
-	bool	monitor_present;
-	bool	eld_valid;
-	int	eld_size;
+struct parsed_hdmi_eld {
+	/*
+	 * all fields will be cleared before updating ELD
+	 */
 	int	baseline_len;
 	int	eld_ver;
 	int	cea_edid_ver;
@@ -731,19 +731,26 @@ struct hdmi_eld {
 	int	spk_alloc;
 	int	sad_count;
 	struct cea_sad sad[ELD_MAX_SAD];
-	/*
-	 * all fields above eld_buffer will be cleared before updating ELD
-	 */
+};
+
+struct hdmi_eld {
+	bool	monitor_present;
+	bool	eld_valid;
+	int	eld_size;
 	char    eld_buffer[ELD_MAX_SIZE];
+	struct parsed_hdmi_eld info;
 #ifdef CONFIG_PROC_FS
 	struct snd_info_entry *proc_entry;
 #endif
 };
 
 int snd_hdmi_get_eld_size(struct hda_codec *codec, hda_nid_t nid);
-int snd_hdmi_get_eld(struct hdmi_eld *, struct hda_codec *, hda_nid_t);
-void snd_hdmi_show_eld(struct hdmi_eld *eld);
-void snd_hdmi_eld_update_pcm_info(struct hdmi_eld *eld,
+int snd_hdmi_get_eld(struct hda_codec *codec, hda_nid_t nid,
+		     unsigned char *buf, int *eld_size);
+int snd_hdmi_parse_eld(struct parsed_hdmi_eld *e,
+		       const unsigned char *buf, int size);
+void snd_hdmi_show_eld(struct parsed_hdmi_eld *e);
+void snd_hdmi_eld_update_pcm_info(struct parsed_hdmi_eld *e,
 			      struct hda_pcm_stream *hinfo);
 
 #ifdef CONFIG_PROC_FS
diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
index 6bcdd66..1e38191 100644
--- a/sound/pci/hda/patch_hdmi.c
+++ b/sound/pci/hda/patch_hdmi.c
@@ -531,7 +531,7 @@ static int hdmi_channel_allocation(struct hdmi_eld *eld, int channels)
 	 * expand ELD's notions to match the ones used by Audio InfoFrame.
 	 */
 	for (i = 0; i < ARRAY_SIZE(eld_speaker_allocation_bits); i++) {
-		if (eld->spk_alloc & (1 << i))
+		if (eld->info.spk_alloc & (1 << i))
 			spk_mask |= eld_speaker_allocation_bits[i];
 	}
 
@@ -545,7 +545,7 @@ static int hdmi_channel_allocation(struct hdmi_eld *eld, int channels)
 		}
 	}
 
-	snd_print_channel_allocation(eld->spk_alloc, buf, sizeof(buf));
+	snd_print_channel_allocation(eld->info.spk_alloc, buf, sizeof(buf));
 	snd_printdd("HDMI: select CA 0x%x for %d-channel allocation: %s\n",
 		    ca, channels, buf);
 
@@ -886,7 +886,7 @@ static void hdmi_setup_audio_infoframe(struct hda_codec *codec, int pin_idx,
 		ca = 0;
 
 	memset(&ai, 0, sizeof(ai));
-	if (eld->conn_type == 0) { /* HDMI */
+	if (eld->info.conn_type == 0) { /* HDMI */
 		struct hdmi_audio_infoframe *hdmi_ai = &ai.hdmi;
 
 		hdmi_ai->type		= 0x84;
@@ -895,7 +895,7 @@ static void hdmi_setup_audio_infoframe(struct hda_codec *codec, int pin_idx,
 		hdmi_ai->CC02_CT47	= channels - 1;
 		hdmi_ai->CA		= ca;
 		hdmi_checksum_audio_infoframe(hdmi_ai);
-	} else if (eld->conn_type == 1) { /* DisplayPort */
+	} else if (eld->info.conn_type == 1) { /* DisplayPort */
 		struct dp_audio_infoframe *dp_ai = &ai.dp;
 
 		dp_ai->type		= 0x84;
@@ -1116,7 +1116,7 @@ static int hdmi_pcm_open(struct hda_pcm_stream *hinfo,
 
 	/* Restrict capabilities by ELD if this isn't disabled */
 	if (!static_hdmi_pcm && eld->eld_valid) {
-		snd_hdmi_eld_update_pcm_info(eld, hinfo);
+		snd_hdmi_eld_update_pcm_info(&eld->info, hinfo);
 		if (hinfo->channels_min > hinfo->channels_max ||
 		    !hinfo->rates || !hinfo->formats) {
 			per_cvt->assigned = 0;
@@ -1177,8 +1177,6 @@ static void hdmi_present_sense(struct hdmi_spec_per_pin *per_pin, int repoll)
 	int present = snd_hda_pin_sense(codec, pin_nid);
 	bool eld_valid = false;
 
-	memset(eld, 0, offsetof(struct hdmi_eld, eld_buffer));
-
 	eld->monitor_present	= !!(present & AC_PINSENSE_PRESENCE);
 	if (eld->monitor_present)
 		eld_valid	= !!(present & AC_PINSENSE_ELDV);
@@ -1189,8 +1187,20 @@ static void hdmi_present_sense(struct hdmi_spec_per_pin *per_pin, int repoll)
 
 	eld->eld_valid = false;
 	if (eld_valid) {
-		if (!snd_hdmi_get_eld(eld, codec, pin_nid))
-			snd_hdmi_show_eld(eld);
+		if (snd_hdmi_get_eld(codec, pin_nid, eld->eld_buffer,
+						     &eld->eld_size) < 0)
+			eld_valid = false;
+		else {
+			memset(&eld->info, 0, sizeof(struct parsed_hdmi_eld));
+			if (snd_hdmi_parse_eld(&eld->info, eld->eld_buffer,
+						    eld->eld_size) < 0)
+				eld_valid = false;
+		}
+
+		if (eld_valid) {
+			snd_hdmi_show_eld(&eld->info);
+			eld->eld_valid = true;
+		}
 		else if (repoll) {
 			queue_delayed_work(codec->bus->workq,
 					   &per_pin->work,
-- 
1.7.9.5

[PATCH v5 4/5] ALSA: hda - hdmi: Protect ELD buffer

[David Henningsson]

Because the eld buffer can be simultaneously accessed from both
workqueue context (updating) and process context (kcontrol read),
we need to protect it with a mutex to guarantee consistency.

To avoid holding the mutex while reading the ELD info from the
codec, we introduce a temporary eld buffer.

Signed-off-by: David Henningsson <david.henningsson@canonical.com>
---
 sound/pci/hda/hda_eld.c    |    8 ++++++-
 sound/pci/hda/hda_local.h  |    1 +
 sound/pci/hda/patch_hdmi.c |   51 +++++++++++++++++++++++++++++++++-----------
 3 files changed, 47 insertions(+), 13 deletions(-)

diff --git a/sound/pci/hda/hda_eld.c b/sound/pci/hda/hda_eld.c
index 16066d7..7dd8463 100644
--- a/sound/pci/hda/hda_eld.c
+++ b/sound/pci/hda/hda_eld.c
@@ -500,10 +500,13 @@ static void hdmi_print_eld_info(struct snd_info_entry *entry,
 		[4 ... 7] = "reserved"
 	};
 
+	mutex_lock(&eld->lock);
 	snd_iprintf(buffer, "monitor_present\t\t%d\n", eld->monitor_present);
 	snd_iprintf(buffer, "eld_valid\t\t%d\n", eld->eld_valid);
-	if (!eld->eld_valid)
+	if (!eld->eld_valid) {
+		mutex_unlock(&eld->lock);
 		return;
+	}
 	snd_iprintf(buffer, "monitor_name\t\t%s\n", e->monitor_name);
 	snd_iprintf(buffer, "connection_type\t\t%s\n",
 				eld_connection_type_names[e->conn_type]);
@@ -525,6 +528,7 @@ static void hdmi_print_eld_info(struct snd_info_entry *entry,
 
 	for (i = 0; i < e->sad_count; i++)
 		hdmi_print_sad_info(i, e->sad + i, buffer);
+	mutex_unlock(&eld->lock);
 }
 
 static void hdmi_write_eld_info(struct snd_info_entry *entry,
@@ -538,6 +542,7 @@ static void hdmi_write_eld_info(struct snd_info_entry *entry,
 	long long val;
 	unsigned int n;
 
+	mutex_lock(&eld->lock);
 	while (!snd_info_get_line(buffer, line, sizeof(line))) {
 		if (sscanf(line, "%s %llx", name, &val) != 2)
 			continue;
@@ -589,6 +594,7 @@ static void hdmi_write_eld_info(struct snd_info_entry *entry,
 				e->sad_count = n + 1;
 		}
 	}
+	mutex_unlock(&eld->lock);
 }
 
 
diff --git a/sound/pci/hda/hda_local.h b/sound/pci/hda/hda_local.h
index 363cd48..83b7486 100644
--- a/sound/pci/hda/hda_local.h
+++ b/sound/pci/hda/hda_local.h
@@ -739,6 +739,7 @@ struct hdmi_eld {
 	int	eld_size;
 	char    eld_buffer[ELD_MAX_SIZE];
 	struct parsed_hdmi_eld info;
+	struct mutex lock;
 #ifdef CONFIG_PROC_FS
 	struct snd_info_entry *proc_entry;
 #endif
diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
index 1e38191..e77735d 100644
--- a/sound/pci/hda/patch_hdmi.c
+++ b/sound/pci/hda/patch_hdmi.c
@@ -91,6 +91,7 @@ struct hdmi_spec {
 	struct hda_pcm pcm_rec[MAX_HDMI_PINS];
 	unsigned int channels_max; /* max over all cvts */
 
+	struct hdmi_eld temp_eld;
 	/*
 	 * Non-generic ATI/NVIDIA specific
 	 */
@@ -352,7 +353,9 @@ static int hdmi_eld_ctl_info(struct snd_kcontrol *kcontrol,
 	pin_idx = kcontrol->private_value;
 	eld = &spec->pins[pin_idx].sink_eld;
 
+	mutex_lock(&eld->lock);
 	uinfo->count = eld->eld_valid ? eld->eld_size : 0;
+	mutex_unlock(&eld->lock);
 
 	return 0;
 }
@@ -368,7 +371,9 @@ static int hdmi_eld_ctl_get(struct snd_kcontrol *kcontrol,
 	pin_idx = kcontrol->private_value;
 	eld = &spec->pins[pin_idx].sink_eld;
 
+	mutex_lock(&eld->lock);
 	if (eld->eld_size > ARRAY_SIZE(ucontrol->value.bytes.data)) {
+		mutex_unlock(&eld->lock);
 		snd_BUG();
 		return -EINVAL;
 	}
@@ -378,6 +383,7 @@ static int hdmi_eld_ctl_get(struct snd_kcontrol *kcontrol,
 	if (eld->eld_valid)
 		memcpy(ucontrol->value.bytes.data, eld->eld_buffer,
 		       eld->eld_size);
+	mutex_unlock(&eld->lock);
 
 	return 0;
 }
@@ -1164,7 +1170,9 @@ static int hdmi_read_pin_conn(struct hda_codec *codec, int pin_idx)
 static void hdmi_present_sense(struct hdmi_spec_per_pin *per_pin, int repoll)
 {
 	struct hda_codec *codec = per_pin->codec;
-	struct hdmi_eld *eld = &per_pin->sink_eld;
+	struct hdmi_spec *spec = codec->spec;
+	struct hdmi_eld *eld = &spec->temp_eld;
+	struct hdmi_eld *pin_eld = &per_pin->sink_eld;
 	hda_nid_t pin_nid = per_pin->pin_nid;
 	/*
 	 * Always execute a GetPinSense verb here, even when called from
@@ -1175,38 +1183,56 @@ static void hdmi_present_sense(struct hdmi_spec_per_pin *per_pin, int repoll)
 	 * the unsolicited response to avoid custom WARs.
 	 */
 	int present = snd_hda_pin_sense(codec, pin_nid);
-	bool eld_valid = false;
+	bool update_eld = false;
+	bool eld_changed = false;
 
-	eld->monitor_present	= !!(present & AC_PINSENSE_PRESENCE);
-	if (eld->monitor_present)
-		eld_valid	= !!(present & AC_PINSENSE_ELDV);
+	pin_eld->monitor_present = !!(present & AC_PINSENSE_PRESENCE);
+	if (pin_eld->monitor_present)
+		eld->eld_valid  = !!(present & AC_PINSENSE_ELDV);
+	else
+		eld->eld_valid = false;
 
 	_snd_printd(SND_PR_VERBOSE,
 		"HDMI status: Codec=%d Pin=%d Presence_Detect=%d ELD_Valid=%d\n",
-		codec->addr, pin_nid, eld->monitor_present, eld_valid);
+		codec->addr, pin_nid, eld->monitor_present, eld->eld_valid);
 
-	eld->eld_valid = false;
-	if (eld_valid) {
+	if (eld->eld_valid) {
 		if (snd_hdmi_get_eld(codec, pin_nid, eld->eld_buffer,
 						     &eld->eld_size) < 0)
-			eld_valid = false;
+			eld->eld_valid = false;
 		else {
 			memset(&eld->info, 0, sizeof(struct parsed_hdmi_eld));
 			if (snd_hdmi_parse_eld(&eld->info, eld->eld_buffer,
 						    eld->eld_size) < 0)
-				eld_valid = false;
+				eld->eld_valid = false;
 		}
 
-		if (eld_valid) {
+		if (eld->eld_valid) {
 			snd_hdmi_show_eld(&eld->info);
-			eld->eld_valid = true;
+			update_eld = true;
 		}
 		else if (repoll) {
 			queue_delayed_work(codec->bus->workq,
 					   &per_pin->work,
 					   msecs_to_jiffies(300));
+			return;
 		}
 	}
+
+	mutex_lock(&pin_eld->lock);
+	if (pin_eld->eld_valid && !eld->eld_valid)
+		update_eld = true;
+	if (update_eld) {
+		pin_eld->eld_valid = eld->eld_valid;
+		eld_changed = memcmp(pin_eld->eld_buffer, eld->eld_buffer,
+				     eld->eld_size) != 0;
+		if (eld_changed)
+			memcpy(pin_eld->eld_buffer, eld->eld_buffer,
+			       eld->eld_size);
+		pin_eld->eld_size = eld->eld_size;
+		pin_eld->info = eld->info;
+	}
+	mutex_unlock(&pin_eld->lock);
 }
 
 static void hdmi_repoll_eld(struct work_struct *work)
@@ -1674,6 +1700,7 @@ static int generic_hdmi_init_per_pins(struct hda_codec *codec)
 		struct hdmi_eld *eld = &per_pin->sink_eld;
 
 		per_pin->codec = codec;
+		mutex_init(&eld->lock);
 		INIT_DELAYED_WORK(&per_pin->work, hdmi_repoll_eld);
 		snd_hda_eld_proc_new(codec, eld, pin_idx);
 	}
-- 
1.7.9.5

[PATCH v5 5/5] ALSA: hda - hdmi: Notify userspace when ELD control changes

[David Henningsson]

ELD validity can change during the lifetime of a presence detect,
so we need to be able to listen for changes on the ELD control.

Signed-off-by: David Henningsson <david.henningsson@canonical.com>
---
 sound/pci/hda/patch_hdmi.c |   14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
index e77735d..21425fb 100644
--- a/sound/pci/hda/patch_hdmi.c
+++ b/sound/pci/hda/patch_hdmi.c
@@ -75,6 +75,7 @@ struct hdmi_spec_per_pin {
 	struct hda_codec *codec;
 	struct hdmi_eld sink_eld;
 	struct delayed_work work;
+	struct snd_kcontrol *eld_ctl;
 	int repoll_count;
 	bool non_pcm;
 	bool chmap_set;		/* channel-map override by ALSA API? */
@@ -413,6 +414,7 @@ static int hdmi_create_eld_ctl(struct hda_codec *codec, int pin_idx,
 	if (err < 0)
 		return err;
 
+	spec->pins[pin_idx].eld_ctl = kctl;
 	return 0;
 }
 
@@ -1220,11 +1222,14 @@ static void hdmi_present_sense(struct hdmi_spec_per_pin *per_pin, int repoll)
 	}
 
 	mutex_lock(&pin_eld->lock);
-	if (pin_eld->eld_valid && !eld->eld_valid)
+	if (pin_eld->eld_valid && !eld->eld_valid) {
 		update_eld = true;
+		eld_changed = true;
+	}
 	if (update_eld) {
 		pin_eld->eld_valid = eld->eld_valid;
-		eld_changed = memcmp(pin_eld->eld_buffer, eld->eld_buffer,
+		eld_changed = pin_eld->eld_size != eld->eld_size ||
+			      memcmp(pin_eld->eld_buffer, eld->eld_buffer,
 				     eld->eld_size) != 0;
 		if (eld_changed)
 			memcpy(pin_eld->eld_buffer, eld->eld_buffer,
@@ -1233,6 +1238,11 @@ static void hdmi_present_sense(struct hdmi_spec_per_pin *per_pin, int repoll)
 		pin_eld->info = eld->info;
 	}
 	mutex_unlock(&pin_eld->lock);
+
+	if (eld_changed)
+		snd_ctl_notify(codec->bus->card,
+			       SNDRV_CTL_EVENT_MASK_VALUE | SNDRV_CTL_EVENT_MASK_INFO,
+			       &per_pin->eld_ctl->id);
 }
 
 static void hdmi_repoll_eld(struct work_struct *work)
-- 
1.7.9.5