[alsa-devel] [PATCH] drm/i915/dp: DP audio API changes for MST

[Takashi Iwai]

On Wed, 03 Aug 2016 04:14:30 +0200,
Dhinakaran Pandiyan wrote:
> 
> DP MST provides the capability to send multiple video and audio streams via
> one single port. This requires the API's between i915 and audio drivers to
> distinguish between audio capable displays connected to a port. This patch
> adds this support via an additional parameter 'int dev_id'. The existing
> parameter 'port' does not change it's meaning.
> 
> dev_id =
> 	MST	: pipe that the stream originates from
> 	Non-MST	: -1
> 
> Affected APIs:
> struct i915_audio_component_ops
> -       int (*sync_audio_rate)(struct device *, int port, int rate);
> +	int (*sync_audio_rate)(struct device *, int port, int dev_id,
> +	     int rate);
> 
> -       int (*get_eld)(struct device *, int port, bool *enabled,
> -                       unsigned char *buf, int max_bytes);
> +       int (*get_eld)(struct device *, int port, int dev_id,
> +		       bool *enabled, unsigned char *buf, int max_bytes);
> 
> struct i915_audio_component_audio_ops
> -       void (*pin_eld_notify)(void *audio_ptr, int port);
> +       void (*pin_eld_notify)(void *audio_ptr, int port, int dev_id);
> 
> This patch makes dummy changes in the audio drivers for build to succeed.

OK, so the explicit dev_id will be passed in future change in the
audio side, right?  It'd be good to write up the grand plan.


> Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
> ---
>  drivers/gpu/drm/i915/i915_drv.h    |  2 +-
>  drivers/gpu/drm/i915/intel_audio.c | 82 +++++++++++++++++++++++++++++---------
>  include/drm/i915_component.h       |  6 +--
>  include/sound/hda_i915.h           | 11 ++---
>  sound/hda/hdac_i915.c              |  9 +++--
>  sound/pci/hda/patch_hdmi.c         |  7 ++--
>  6 files changed, 82 insertions(+), 35 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 65ada5d..8e4c8c8 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -2054,7 +2054,7 @@ struct drm_i915_private {
>  	/* perform PHY state sanity checks? */
>  	bool chv_phy_assert[2];
>  
> -	struct intel_encoder *dig_port_map[I915_MAX_PORTS];
> +	struct intel_encoder *av_enc_map[I915_MAX_PIPES];

Better to have a comment for this field.


> -static int i915_audio_component_sync_audio_rate(struct device *dev,
> -						int port, int rate)
> +static struct intel_encoder *get_saved_encoder(struct intel_encoder *av_enc_map[],
> +					       int port, int dev_id)
> +{
> +
> +	enum pipe pipe;
> +	struct drm_encoder *encoder;
> +
> +	if (dev_id >= 0 && dev_id < I915_MAX_PIPES)
> +		return av_enc_map[dev_id];

Actually dev_id >= I915_MAX_PIPES is an invalid call, and worth to
catch with WARN_ON() and bail out.


thanks,

Takashi