Re: [PATCH 8/8] drm/bridge: dw-hdmi-i2s: add .get_eld support

[Jonas Karlman]

On 2019-08-05 15:41, Jerome Brunet wrote:
> Provide the eld to the generic hdmi-codec driver.
> This will let the driver enforce the maximum channel number and set the
> channel allocation depending on the hdmi sink.
>
> Cc: Jonas Karlman <jonas@xxxxxxxxx>
> Signed-off-by: Jerome Brunet <jbrunet@xxxxxxxxxxxx>
> ---
>  drivers/gpu/drm/bridge/synopsys/dw-hdmi-audio.h     |  1 +
>  drivers/gpu/drm/bridge/synopsys/dw-hdmi-i2s-audio.c | 10 ++++++++++
>  drivers/gpu/drm/bridge/synopsys/dw-hdmi.c           |  1 +
>  3 files changed, 12 insertions(+)
>
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-audio.h b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-audio.h
> index 63b5756f463b..cb07dc0da5a7 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-audio.h
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-audio.h
> @@ -14,6 +14,7 @@ struct dw_hdmi_audio_data {
>  
>  struct dw_hdmi_i2s_audio_data {
>  	struct dw_hdmi *hdmi;
> +	u8 *eld;
>  
>  	void (*write)(struct dw_hdmi *hdmi, u8 val, int offset);
>  	u8 (*read)(struct dw_hdmi *hdmi, int offset);
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-i2s-audio.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-i2s-audio.c
> index b8ece9c1ba2c..14d499b344c0 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-i2s-audio.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-i2s-audio.c
> @@ -121,6 +121,15 @@ static void dw_hdmi_i2s_audio_shutdown(struct device *dev, void *data)
>  	dw_hdmi_audio_disable(hdmi);
>  }
>  
> +static int dw_hdmi_i2s_get_eld(struct device *dev, void *data, uint8_t *buf,
> +			       size_t len)
> +{
> +	struct dw_hdmi_i2s_audio_data *audio = data;
> +
> +	memcpy(buf, audio->eld, min(sizeof(audio->eld), len));

Above sizeof does not work as intended, sizeof(audio->eld) is probably the size of a pointer and not MAX_ELD_BYTES (128),
resulting in only part of the ELD gets copied to buf.


Thanks for reworking dw-hdmi multi channel lpcm support!, this works on Rockchip for most parts.
Without the [1] patch (reset cts+n after clock is enabled) audio sometime stay silent when switching between e.g. 2ch 44.1khz and 6ch 48khz tracks.
It is not fully clear to me why reset cts+n helps, if that have negative affects on other platforms or if there is another way to solve loosing audio.

I also have a small issue with the channel allocation being selected by hdmi-codec, my soundbar reports LPCM 6.1ch instead of LPCM 7.1ch when I play a 7.1ch speaker test clip.
I have a hdmi-codec patch to fix selection of channel allocation in queue.


For patch 1-7:

Reviewed-by: Jonas Karlman <jonas@xxxxxxxxx>


[1] https://github.com/Kwiboo/linux-rockchip/commit/c0839e874f843ad173ddde958303d6878394ef92

Regards,
Jonas

> +	return 0;
> +}
> +
>  static int dw_hdmi_i2s_get_dai_id(struct snd_soc_component *component,
>  				  struct device_node *endpoint)
>  {
> @@ -144,6 +153,7 @@ static int dw_hdmi_i2s_get_dai_id(struct snd_soc_component *component,
>  static struct hdmi_codec_ops dw_hdmi_i2s_ops = {
>  	.hw_params	= dw_hdmi_i2s_hw_params,
>  	.audio_shutdown	= dw_hdmi_i2s_audio_shutdown,
> +	.get_eld	= dw_hdmi_i2s_get_eld,
>  	.get_dai_id	= dw_hdmi_i2s_get_dai_id,
>  };
>  
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> index bed4bb017afd..8df69c9dbfad 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> @@ -2797,6 +2797,7 @@ __dw_hdmi_probe(struct platform_device *pdev,
>  		struct dw_hdmi_i2s_audio_data audio;
>  
>  		audio.hdmi	= hdmi;
> +		audio.eld	= hdmi->connector.eld;
>  		audio.write	= hdmi_writeb;
>  		audio.read	= hdmi_readb;
>  		hdmi->enable_audio = dw_hdmi_i2s_audio_enable;