ALSA: pcm: Harden the spk_alloc assumption check

[PATCH] ALSA: pcm: Harden the spk_alloc assumption check

Posted by Umang Jain 1 week, 4 days ago

If the parsed ELD has spk_alloc=0, it currently assigns the parsed ELD
spk_alloc to 0xffff. However, we should also check if there is at least
one SAD (Short audio descriptor) to enforce the assumption, as ELD
without any sad_count, is usually considered invalid for e.g. in
commit ce9778b7a0272("ALSA: hda/hdmi: Consider ELD is invalid when no
SAD is present").

Signed-off-by: Umang Jain <uajain@igalia.com>
---
 sound/core/pcm_drm_eld.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sound/core/pcm_drm_eld.c b/sound/core/pcm_drm_eld.c
index 688eefce82fa..cb2eebaac85f 100644
--- a/sound/core/pcm_drm_eld.c
+++ b/sound/core/pcm_drm_eld.c
@@ -379,7 +379,7 @@ int snd_parse_eld(struct device *dev, struct snd_parsed_hdmi_eld *e,
 	 * in console or for audio devices. Assume the highest speakers
 	 * configuration, to _not_ prohibit multi-channel audio playback.
 	 */
-	if (!e->spk_alloc)
+	if (!e->spk_alloc && e->sad_count)
 		e->spk_alloc = 0xffff;
 
 	return 0;
-- 
2.51.2

Re: [PATCH] ALSA: pcm: Harden the spk_alloc assumption check

Posted by Takashi Iwai 1 week, 3 days ago

On Thu, 20 Nov 2025 15:17:57 +0100,
Umang Jain wrote:
> 
> If the parsed ELD has spk_alloc=0, it currently assigns the parsed ELD
> spk_alloc to 0xffff. However, we should also check if there is at least
> one SAD (Short audio descriptor) to enforce the assumption, as ELD
> without any sad_count, is usually considered invalid for e.g. in
> commit ce9778b7a0272("ALSA: hda/hdmi: Consider ELD is invalid when no
> SAD is present").
> 
> Signed-off-by: Umang Jain <uajain@igalia.com>

Thanks, applied now.


Takashi