Re: [alsa-devel] [PATCH] ALSA: SoC: Added jack detection kcontrol support
On Fri, Jul 19, 2013 at 05:59:22PM -0700, Felipe F. Tonello wrote:
From: "Felipe F. Tonello" ftonello@cercacor.com
It adds soc jack support for alsa kcontrol.
This support is necessary since the new kcontrol is used by user-space daemons, such as PulseAudio(>=2.0), to do jack detection.
Signed-off-by: Felipe F. Tonello ftonello@cercacor.com
include/sound/soc.h | 1 + sound/soc/Kconfig | 1 + sound/soc/soc-jack.c | 22 ++++++++++++++++++++++ 3 files changed, 24 insertions(+)
No, this makes no sense at all as an ASoC specific feature - it should be a standard feature of ALSA jacks. The whole point of having ALSA core infrastructure for jacks is to avoid having to go round doing make work stuff like this.
The fact that the kcontrols were introduced as a HDA-specific feature at all is of course a problem here...
Hi Mark,
On Sun, Jul 21, 2013 at 5:01 PM, Mark Brown broonie@kernel.org wrote:
On Fri, Jul 19, 2013 at 05:59:22PM -0700, Felipe F. Tonello wrote:
From: "Felipe F. Tonello" ftonello@cercacor.com
It adds soc jack support for alsa kcontrol.
This support is necessary since the new kcontrol is used by user-space daemons, such as PulseAudio(>=2.0), to do jack detection.
Signed-off-by: Felipe F. Tonello ftonello@cercacor.com
include/sound/soc.h | 1 + sound/soc/Kconfig | 1 + sound/soc/soc-jack.c | 22 ++++++++++++++++++++++ 3 files changed, 24 insertions(+)
No, this makes no sense at all as an ASoC specific feature - it should be a standard feature of ALSA jacks. The whole point of having ALSA core infrastructure for jacks is to avoid having to go round doing make work stuff like this.
I agree. I added as a ASoC feature because I followed the example of HDA implementation.
My question is: Why ALSA Jack support uses evdev input events to notify user-space? Is there any user-space relying on that? If no, I would like to change ALSA Jack implementation to only use KControl and remove specific implementations.
At least the only daemon that I know that supports jack detection, which is PulseAudio, uses this new ALSA KControl for Jacks.
Regards, Felipe Tonello
On Mon, Jul 22, 2013 at 02:11:44PM -0700, Felipe Tonello wrote:
My question is: Why ALSA Jack support uses evdev input events to notify user-space? Is there any user-space relying on that? If no, I would like to change ALSA Jack implementation to only use KControl and remove specific implementations.
This was the existing kernel API at the time that the code was added - I beleive people had been doing that for simple switches that detect the physical presence of a jack since it looks exactly like a button from a hardware point of view. See the original commit adding the code.
Hi Mark,
On Tue, Jul 23, 2013 at 5:40 AM, Mark Brown broonie@kernel.org wrote:
On Mon, Jul 22, 2013 at 02:11:44PM -0700, Felipe Tonello wrote:
My question is: Why ALSA Jack support uses evdev input events to notify user-space? Is there any user-space relying on that? If no, I would like to change ALSA Jack implementation to only use KControl and remove specific implementations.
This was the existing kernel API at the time that the code was added - I beleive people had been doing that for simple switches that detect the physical presence of a jack since it looks exactly like a button from a hardware point of view. See the original commit adding the code.
I saw it. I don't know what you think is the best way to go. I'm not sure if someone is using this input event API, since even PulseAudio even declined that implementation due KControl implementation.
I'm thinking in re-implement core/jack.c using only kcontrol for reporting status and leaving input events only for keys (which is already implemented). This will break compatibility if any user-space checks for jack status using input events, but again, is anyone using this?
Regards,
Felipe Tonello
On Tue, Jul 23, 2013 at 05:10:29PM -0700, Felipe Tonello wrote:
On Tue, Jul 23, 2013 at 5:40 AM, Mark Brown broonie@kernel.org wrote:
This was the existing kernel API at the time that the code was added - I beleive people had been doing that for simple switches that detect the physical presence of a jack since it looks exactly like a button from a hardware point of view. See the original commit adding the code.
I saw it. I don't know what you think is the best way to go. I'm not sure if someone is using this input event API, since even PulseAudio even declined that implementation due KControl implementation.
It's used quite a bit in embedded systems, there are actually patches for PulseAudio which were deployed for a while - I guess they might have been removed or something. The kcontrol stuff was actually implemented after that was already in place.
I'm thinking in re-implement core/jack.c using only kcontrol for reporting status and leaving input events only for keys (which is already implemented). This will break compatibility if any user-space checks for jack status using input events, but again, is anyone using this?
The jack core should be implementing all three methods of reporting jacks (input, controls and extcon).
On 07/24/2013 02:13 AM, Mark Brown wrote:
On Tue, Jul 23, 2013 at 05:10:29PM -0700, Felipe Tonello wrote:
On Tue, Jul 23, 2013 at 5:40 AM, Mark Brown broonie@kernel.org wrote:
This was the existing kernel API at the time that the code was added - I beleive people had been doing that for simple switches that detect the physical presence of a jack since it looks exactly like a button from a hardware point of view. See the original commit adding the code.
I saw it. I don't know what you think is the best way to go. I'm not sure if someone is using this input event API, since even PulseAudio even declined that implementation due KControl implementation.
It's used quite a bit in embedded systems, there are actually patches for PulseAudio which were deployed for a while- I guess they might have been removed or something.
The input event implementation was only in Ubuntu (for a release or two), and was never merged in upstream PA. (I guess one could find them by looking in the Ubuntu archives.)
participants (3)
-
David Henningsson -
Felipe Tonello -
Mark Brown