Hi Nikolaus, Mark,

Le mer., déc. 1 2021 at 14:51:51 +0100, H. Nikolaus Schaller 
[off-list ref] a écrit :

Hi,

quoted

 Am 01.12.2021 um 14:39 schrieb Mark Brown [off-list ref]:

 On Wed, Dec 01, 2021 at 01:02:45PM +0000, Paul Cercueil wrote:

quoted

 Le mar., nov. 30 2021 at 22:26:37 +0100, H. Nikolaus Schaller

quoted

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 +	regulator = devm_regulator_get_optional(&pdev->dev, "hdmi-5v");
 +	if (IS_ERR(regulator)) {
 +		ret = PTR_ERR(regulator);

 Why is this using _optional()?  This should only be done when the 
supply
 can be physically absent

There can be +5V for HDMI but without a regulator that is visible to 
or controllable
by the driver.

There is always a power supply though. Either a controllable one 
(through e.g. a GPIO), or it's just connected to the mains +5V; the pin 
is never left floating. In the second case, in DTS the "hdmi-5v" would 
be connected to some 5v regulator, even if it's just a dummy VCC-5V 
regulator. So Mark has a point.

So hdmi-5v can be simply missing in DTS in which case the driver does 
not need to
care about. The driver just can't turn it on or off.

Please make it mandatory in DTS then, and use devm_regulator_get() in 
the driver.

Cheers,
-Paul

quoted

 (in which case I'd expect to see special
 handling).

The special case is to not enable/disable the regulator if it does 
not exist
and assume that there is hardware providing it otherwise (the driver 
can't know
that except by using get_optional). This is done by the code below

quoted

quoted

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 +	if (IS_ERR(regulator)) {

...

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 +	if (!regulator)
 +		return 0;

 +	ret = regulator_enable(regulator);

...

BR and thanks,
Nikolaus