ALSA: hda - hdmi: Protect ELD buffer
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>
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 1e38191..e77735d 100644
--- a/sound/pci/hda/patch_hdmi.c
+++ b/sound/pci/hda/patch_hdmi.c
@@ -91,6 +91,7 @@
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 @@
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 @@
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 @@
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 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 @@
* 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 @@
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);
}