Subject: Re: [PATCH] drm/bridge: dw-hdmi: handle ELD when
 DRM_BRIDGE_ATTACH_NO_CONNECTOR
To:     =?UTF-8?Q?Jernej_=c5=a0krabec?= <jernej.skrabec@gmail.com>,
        a.hajda@samsung.com, Laurent.pinchart@ideasonboard.com,
        robert.foss@linaro.org, jonas@kwiboo.se
Cc:     daniel@ffwll.ch, dri-devel@lists.freedesktop.org,
        linux-kernel@vger.kernel.org,
        Martin Blumenstingl <martin.blumenstingl@googlemail.com>
References: <20211029135947.3022875-1-narmstrong@baylibre.com>
 <5763693.lOV4Wx5bFT@kista>
From:   Neil Armstrong <narmstrong@baylibre.com>
Organization: Baylibre
Message-ID: <fa1e0e69-bb37-272b-cfb4-4f45df8a0fa1@baylibre.com>
Date:   Fri, 12 Nov 2021 10:01:29 +0100
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Hi Jernej,

On 10/11/2021 20:20, Jernej Škrabec wrote:
> Hi Neil,
> 
> sorry for late response.
> 
> Dne petek, 29. oktober 2021 ob 15:59:47 CET je Neil Armstrong napisal(a):
>> The current ELD handling takes the internal connector ELD buffer and
>> shares it to the I2S and AHB sub-driver.
>>
>> But with DRM_BRIDGE_ATTACH_NO_CONNECTOR, the connector is created
>> elsewhere (not not), and an eventual connector is known only
> 
> ^ typo, 2x "not"

thx, fixing while applying !

> 
> Other than that, it looks good.
> 
> Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>

Applying to drm-misc-next

Thanks,
Neil

> 
> Best regards,
> Jernej
> 
>> if the bridge chain up to a connector is enabled.
>>
>> The current dw-hdmi code gets the current connector from
>> atomic_enable() so use the already stored connector pointer and
>> replace the buffer pointer with a callback returning the current
>> connector ELD buffer.
>>
>> Since a connector is not always available, either pass an empty
>> ELD to the alsa HDMI driver or don't call snd_pcm_hw_constraint_eld()
>> in AHB driver.
>>
>> Reported-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
>> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
>> ---
>>  drivers/gpu/drm/bridge/synopsys/dw-hdmi-ahb-audio.c | 10 +++++++---
>>  drivers/gpu/drm/bridge/synopsys/dw-hdmi-audio.h     |  4 ++--
>>  drivers/gpu/drm/bridge/synopsys/dw-hdmi-i2s-audio.c |  9 ++++++++-
>>  drivers/gpu/drm/bridge/synopsys/dw-hdmi.c           | 12 ++++++++++--
>>  4 files changed, 27 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-ahb-audio.c b/drivers/
> gpu/drm/bridge/synopsys/dw-hdmi-ahb-audio.c
>> index d0db1acf11d7..7d2ed0ed2fe2 100644
>> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-ahb-audio.c
>> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-ahb-audio.c
>> @@ -320,13 +320,17 @@ static int dw_hdmi_open(struct snd_pcm_substream 
> *substream)
>>  	struct snd_pcm_runtime *runtime = substream->runtime;
>>  	struct snd_dw_hdmi *dw = substream->private_data;
>>  	void __iomem *base = dw->data.base;
>> +	u8 *eld;
>>  	int ret;
>>  
>>  	runtime->hw = dw_hdmi_hw;
>>  
>> -	ret = snd_pcm_hw_constraint_eld(runtime, dw->data.eld);
>> -	if (ret < 0)
>> -		return ret;
>> +	eld = dw->data.get_eld(dw->data.hdmi);
>> +	if (eld) {
>> +		ret = snd_pcm_hw_constraint_eld(runtime, eld);
>> +		if (ret < 0)
>> +			return ret;
>> +	}
>>  
>>  	ret = snd_pcm_limit_hw_rates(runtime);
>>  	if (ret < 0)
>> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-audio.h b/drivers/gpu/
> drm/bridge/synopsys/dw-hdmi-audio.h
>> index cb07dc0da5a7..f72d27208ebe 100644
>> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-audio.h
>> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-audio.h
>> @@ -9,15 +9,15 @@ struct dw_hdmi_audio_data {
>>  	void __iomem *base;
>>  	int irq;
>>  	struct dw_hdmi *hdmi;
>> -	u8 *eld;
>> +	u8 *(*get_eld)(struct dw_hdmi *hdmi);
>>  };
>>  
>>  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);
>> +	u8 *(*get_eld)(struct dw_hdmi *hdmi);
>>  };
>>  
>>  #endif
>> 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 feb04f127b55..f50b47ac11a8 100644
>> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-i2s-audio.c
>> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-i2s-audio.c
>> @@ -135,8 +135,15 @@ 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;
>> +	u8 *eld;
>> +
>> +	eld = audio->get_eld(audio->hdmi);
>> +	if (eld)
>> +		memcpy(buf, eld, min_t(size_t, MAX_ELD_BYTES, len));
>> +	else
>> +		/* Pass en empty ELD if connector not available */
>> +		memset(buf, 0, len);
>>  
>> -	memcpy(buf, audio->eld, min_t(size_t, MAX_ELD_BYTES, len));
>>  	return 0;
>>  }
>>  
>> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/
> bridge/synopsys/dw-hdmi.c
>> index 62ae63565d3a..54d8fdad395f 100644
>> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
>> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
>> @@ -757,6 +757,14 @@ static void hdmi_enable_audio_clk(struct dw_hdmi *hdmi, 
> bool enable)
>>  	hdmi_writeb(hdmi, hdmi->mc_clkdis, HDMI_MC_CLKDIS);
>>  }
>>  
>> +static u8 *hdmi_audio_get_eld(struct dw_hdmi *hdmi)
>> +{
>> +	if (!hdmi->curr_conn)
>> +		return NULL;
>> +
>> +	return hdmi->curr_conn->eld;
>> +}
>> +
>>  static void dw_hdmi_ahb_audio_enable(struct dw_hdmi *hdmi)
>>  {
>>  	hdmi_set_cts_n(hdmi, hdmi->audio_cts, hdmi->audio_n);
>> @@ -3432,7 +3440,7 @@ struct dw_hdmi *dw_hdmi_probe(struct platform_device 
> *pdev,
>>  		audio.base = hdmi->regs;
>>  		audio.irq = irq;
>>  		audio.hdmi = hdmi;
>> -		audio.eld = hdmi->connector.eld;
>> +		audio.get_eld = hdmi_audio_get_eld;
>>  		hdmi->enable_audio = dw_hdmi_ahb_audio_enable;
>>  		hdmi->disable_audio = dw_hdmi_ahb_audio_disable;
>>  
>> @@ -3445,7 +3453,7 @@ struct dw_hdmi *dw_hdmi_probe(struct platform_device 
> *pdev,
>>  		struct dw_hdmi_i2s_audio_data audio;
>>  
>>  		audio.hdmi	= hdmi;
>> -		audio.eld	= hdmi->connector.eld;
>> +		audio.get_eld	= hdmi_audio_get_eld;
>>  		audio.write	= hdmi_writeb;
>>  		audio.read	= hdmi_readb;
>>  		hdmi->enable_audio = dw_hdmi_i2s_audio_enable;
>> -- 
>> 2.25.1
>>
>>
> 
>