-----Original Message----- From: Takashi Iwai [mailto:tiwai@suse.de] Sent: Wednesday, November 11, 2015 11:00 PM To: Yang, Libin Cc: libin.yang@linux.intel.com; David Henningsson; alsa-devel@alsa- project.org; mengdong.lin@linux.intel.com Subject: Re: [PATCH] ALSA - hda: hdmi flag to stop playback when monitor is disconnected
On Wed, 11 Nov 2015 15:43:00 +0100, Yang, Libin wrote:
-----Original Message----- From: Yang, Libin Sent: Wednesday, November 11, 2015 10:24 PM To: 'Takashi Iwai'; libin.yang@linux.intel.com Cc: David Henningsson; alsa-devel@alsa-project.org; mengdong.lin@linux.intel.com Subject: RE: [PATCH] ALSA - hda: hdmi flag to stop playback when monitor is disconnected
-----Original Message----- From: Takashi Iwai [mailto:tiwai@suse.de] Sent: Wednesday, November 11, 2015 10:13 PM To: libin.yang@linux.intel.com Cc: David Henningsson; alsa-devel@alsa-project.org; mengdong.lin@linux.intel.com; Yang, Libin Subject: Re: [PATCH] ALSA - hda: hdmi flag to stop playback when monitor is disconnected
On Wed, 11 Nov 2015 10:02:14 +0100, Takashi Iwai wrote:
On Wed, 11 Nov 2015 09:39:09 +0100, libin.yang@linux.intel.com wrote:
From: Libin Yang libin.yang@linux.intel.com
Add a flag that user can decide to stop HDMI/DP playback when the corresponding monitor is disconnected and refuse to open
PCM
if there is no monitor connected.
Background: When a monitor is disconnected and a new monitor is connected, the parameters of the 2 monitors may be different. Audio driver need handle this situation.
Besides, stopping playback when monitor is disconnected will help to save the power.
Signed-off-by: Libin Yang libin.yang@linux.intel.com
Thanks. Below are just nitpicking, so let's test this patch at first, especially to see whether it has any significant influence on PA,
then
respin with the fixes.
David, care to check in your side, too?
So I tested this with PA 7.1, and it failed, unfortunately. In short:
- PA needs the PCM access at probe. If it gets an error, the device will be never enumerated again
Thanks for test.
If so, should we re-write the hdmi_pcm_open() and generic_hdmi_playback_pcm_prepare() function to make the probe works? Or not support dynamic pcm assignment?
- PA removes the device when it's disconnected. The PCM stop with DISCONNECT state leads to the device disappearance.
If we can't use DISCONNECT, what else can we use? Or we can't stop PCM when monitor is disconnected?
BTW: I did the test on aplay. But I missed the test on PA. Where can I get the PA test cases?
Just use PA on your desktop. Start PA with and without monitor plugged. Play via DP, then unplug, then watch the state change of PA.
Get it. Thanks.
Regards, Libin
Takashi