Pierre-Louis Bossart wrote at Tuesday, September 27, 2011 9:49 AM: ...
Set the access field to SNDRV_CTL_ELEM_ACCESS_READ. Also, unless we implement a notification, better to set SNDRV_CTL_ELEM_ACCESS_VOLATILE flag, too.
The intent was to read the ELD after the device is opened, I don't think the ELD can change during playback, the updates can only happen on a pin-sensing event. I can't think of a good reason why a notification would be needed?
If the user unplugs an HDMI monitor and plugs a different one in, and hence the X server turns off the output and re-enables it to cater for any required new display mode, would that force the audio client to close/re-open the audio device? I don't /think/ so. As such, I guess the ELD can change dynamically, so notification would be a good idea.