ALSA: hda - hdmi: Fix missing ELD change event on plug/unplug

The ELD ALSA control change event is sent by hdmi_present_sense() when
eld_changed is true.

Currently, it is only true when the ELD buffer contents have been
modified. However, the user-visible ELD controls also change to a
zero-length value and back when eld_valid is unset/set, and no event is
currently sent in such cases (such as when unplugging or replugging a
sink).

Fix the code to always set eld_changed if eld_valid value is changed,
and therefore to always send the change event when the user-visible
value changes.

Signed-off-by: Anssi Hannula <anssi.hannula@iki.fi>
Cc: David Henningsson <david.henningsson@canonical.com>
Cc: <stable@vger.kernel.org> # 3.9+
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 9 insertions, 6 deletions

diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
index 39862e98551c..9dc9cf8c90e9 100644
--- a/sound/pci/hda/patch_hdmi.c
+++ b/sound/pci/hda/patch_hdmi.c
@@ -1583,19 +1583,22 @@ static bool hdmi_present_sense(struct hdmi_spec_per_pin *per_pin, int repoll)
                 }
         }
 
-        if (pin_eld->eld_valid && !eld->eld_valid) {
-                update_eld = true;
+        if (pin_eld->eld_valid != eld->eld_valid)
                 eld_changed = true;
-        }
+
+        if (pin_eld->eld_valid && !eld->eld_valid)
+                update_eld = true;
+
         if (update_eld) {
                 bool old_eld_valid = pin_eld->eld_valid;
                 pin_eld->eld_valid = eld->eld_valid;
-                eld_changed = pin_eld->eld_size != eld->eld_size ||
+                if (pin_eld->eld_size != eld->eld_size ||
                               memcmp(pin_eld->eld_buffer, eld->eld_buffer,
-                                     eld->eld_size) != 0;
-                if (eld_changed)
+                                     eld->eld_size) != 0) {
                         memcpy(pin_eld->eld_buffer, eld->eld_buffer,
                                eld->eld_size);
+                        eld_changed = true;
+                }
                 pin_eld->eld_size = eld->eld_size;
                 pin_eld->info = eld->info;