[alsa-devel] [RFC PATCH 0/2] hdmi audio dynamically bind PCM to pin

[Takashi Iwai]

On Wed, 18 Nov 2015 09:46:57 +0100,
libin.yang at linux.intel.com wrote:
> 
> From: Libin Yang <libin.yang at linux.intel.com>
> 
> The patches are trying to support dynamically binding PCM to pin in HDMI audio.
> 
> The first patch:
> When PCM is open when there is no pin (port) bound to the PCM,
> the driver try to open the PCM successfully. It will try to find
> an available converter to assign to the PCM.
> In PCM prepare, if there is no pin bound to the PCM, the driver
> will do the simple configuration and return true.
> In PCM close, if there is no pin bound to the PCM, the driver will
> simply close it.
> All the pin configuration will be setup in the hotplug which is done
> in patch 2.
> As the PCM is dynamically bound to the pin, the pcm_lock is necessary
> for the whole pcm open/prepare/close process.

Such a detailed explanation should be put into the patch itself, not
in the cover letter.  The current description is way too sparse.


Takashi

> The second patch:
> The patch mainly handle the hotplug event.
> Each time monitor is connected, a proper PCM will be bound to the pin.
> If the PCM is in use, the pin must be configured.
> Each time monitor is disconnect, the PCM will be unbound from the pin.
> The pin will be reset.
> Libin Yang (2):
>   ALSA: hda - hdmi playback without monitor in dynamic pcm bind mode
>   ALSA: hda - hdmi dynamically bind PCM to pin when monitor hotplug
> 
>  sound/pci/hda/hda_codec.h  |   1 +
>  sound/pci/hda/patch_hdmi.c | 354 ++++++++++++++++++++++++++++++++++++++++++---
>  2 files changed, 337 insertions(+), 18 deletions(-)
> 
> -- 
> 1.9.1
>