[alsa-devel] [PATCH 4/6] ASoC: OMAP: Add CPU DAI driver for HDMI

Mark Brown broonie at opensource.wolfsonmicro.com
Sun May 8 12:34:02 CEST 2011

On Sat, May 07, 2011 at 07:05:17PM -0500, Ricardo Neri wrote:
> Am Freitag, den 06.05.2011, 08:21 -0500 schrieb Mark Brown:

> > Why do you need to check at all?  The playback won't work when the
> > output isn't connected but the application layer will find that out when
> > there's no data transfer anyway.  If you implement the check in startup
> > I'd imagine there may be some races with hotplug of HDMI cables.

> I need to check somewhere if the Display Subsystem (and the HDMI IP) is
> on. Otherwise I will have L3 interconnect errors when trying to access
> the DSS while it is power-disconnected. I need the HDMI IP on for
> getting configurations (e.g, deep color mode) and use the HDMI audio

I repeat my question - why do you need to check this?  You'll get errors
but you're generating an error anyway so it's not clear what the urgency

> Can you clarify what kind of races with hotplug are you concerned? The
> DSS would detect cable connection events and power on the HDMI IP
> accordingly. HDMI audio driver would only check if it is powered-on.

Something noticing that the cable is plugged in and trying to begin
audio setup while the link is still being initialised.

More information about the Alsa-devel mailing list