Re: [PATCH v2 2/4] ASoC: qcom: common: add Display port Jack function

From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
To: Johan Hovold <johan@kernel.org>
Cc: broonie@kernel.org, perex@perex.cz, tiwai@suse.com,
	lgirdwood@gmail.com, alsa-devel@alsa-project.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 2/4] ASoC: qcom: common: add Display port Jack function
Date: Thu, 9 May 2024 09:59:40 +0100	[thread overview]
Message-ID: <a980d7a5-0d80-4ff1-93e1-b5f5806980c3@linaro.org> (raw)
In-Reply-To: <Zi-0kSU6TMcev05r@hovoldconsulting.com>

On 29/04/2024 15:54, Johan Hovold wrote:
> On Tue, Apr 23, 2024 at 04:55:32PM +0100, Srinivas Kandagatla wrote:
>> On 23/04/2024 13:02, Johan Hovold wrote:
>>> On Mon, Apr 22, 2024 at 02:43:52PM +0100, Srinivas Kandagatla wrote:
>>>    
>>>>    static const struct snd_soc_dapm_widget qcom_jack_snd_widgets[] = {
>>>>    	SND_SOC_DAPM_HP("Headphone Jack", NULL),
>>>>    	SND_SOC_DAPM_MIC("Mic Jack", NULL),
>>>> +	SND_SOC_DAPM_SPK("HDMI/DP0 Jack", NULL),
>>>> +	SND_SOC_DAPM_SPK("HDMI/DP1 Jack", NULL),
>>>> +	SND_SOC_DAPM_SPK("HDMI/DP2 Jack", NULL),
>>>
>>> Shouldn't these be split in dedicated HDMI and DP jacks too? What if you
>>> have a machine with HDMI and DP jacks which would otherwise both claim
>>> "HDMI/DP0"?
>>
>> These map to the Jack's added as part of qcom_snd_dp_jack_setup and
>> belong to DISPLAY_PORT_RX_0, DISPLAY_PORT_RX_1, DISPLAY_PORT_RX_2.
>>
>> If its going via USB-C DP controller it will be either DP or an HDMI ?
> 
> It will always be DP out of the machine even if an adapter can convert
> to HDMI internally.
> 
> The DRM ports are called "DP-1" and "DP-2" so it seems we should match
> that.
> 
>> This is the most common naming for the USB-C DP/HDMI jack events.
> 
> It looks like some Intel machines use names like "HDMI/DP, pcm=%d Jack"
> (with a pcm device number), but we also have "DP Jack". Not sure which
> are are used with USB-C, though. (Or if the former actually support HDMI
> altmode.)

I checked this on my machine which has usb-c and I can confirm using 
HDMI/DP naming for these jack.

Either way I don't mind having any names, but my point here is to be 
more consistent across.

--srini
> 
>> Qualcomm LPASS in some older SoCs had a dedicated HDMI interface which
>> is different to this one.
>>
>> Usual Other ways to connect HDMI is via external HDMI Bridge using I2S
>> interface which totally different to this DP interface.
> 
> Sure, but if there's ever a design with such a port then it will be
> called "HDMI Jack" and then the "HDMI in "HDMI/DP0 Jack" is unnecessary
> and confusing when it is always DP out.
> 
> Johan