Re: [PATCH 2/2] drm/bridge: lt9211: Add drive-strength-microamp DT property

[Marek Vasut <marex@nabladev.com>]

On 5/13/26 11:02 AM, Börge Strümpfel wrote:

[...]

>>> +	ctx->lvds_hsdrv_isel = 8; /* default: 25 uA */
>>> +	ret = of_property_read_u32(dev->of_node, "drive-strength-microamp",
>>> +				   &microamp);
>>
>> if ret != 0 , then what happens here ?
>>
> 
> if ret != 0, we will keep the default value of 8 (corresponding to 25 uA
> as written above), which is the behavior that the driver had previously.
> 
> According to the documentation, of_property_read_u32() will return 0 on
> success, -EINVAL if the property does not exist, -ENODATA if property
> does not have a value, and -EOVERFLOW if the property data isn't large
> enough. I think we only would need to give a warning or similar if the
> -ENODATA or -EOVERFLOW cases. However, I personally do not think that is
> necessary, as the usage is specified unambiguously in the devicetree
> bindings.
Users can pass in malformed DT, so a warning is a good idea. Thanks.