[PATCH] drm/Kconfig: add missing 'depends on DRM' for DRM_DP_CEC

[Hans Verkuil]

On 1/8/20 6:42 PM, Daniel Vetter wrote:
> On Wed, Jan 08, 2020 at 01:08:47PM +0100, Hans Verkuil wrote:
>> On 12/6/19 12:26 PM, Hans Verkuil wrote:
>>> Add a missing 'depends on DRM' for the DRM_DP_CEC config
>>> option. Without that enabling DRM_DP_CEC will force CEC_CORE
>>> to =y instead of =m if DRM=m as well.
>>>
>>> Signed-off-by: Hans Verkuil <hverkuil-cisco at xs4all.nl>
>>
>> Daniel, can you review this? It's annoying that the cec core is
>> compiled as part of the kernel when it can just be a module.
> 
> Why did we even make this optional? Really worth it to compile out 4
> functions and some change?

It's not about those few functions, it's because this enables the CEC
framework as well (drivers/media/cec).

If CEC is not needed, then disabling this saves a lot more code than the
few functions in drm_dp_cec.c.

CEC is an optional HDMI feature, so CEC support for HDMI input/output
drivers is optional as well in the kernel config.

Regards,

	Hans

> 
> Anyway the one you really want here is CONFIG_DRM_KMS_HELPER, but that is
> a selected variable, and you can't mix select and depends on because that
> breaks Kconfig in hilarious ways. Or so I thought, but other public
> symbols like this (e.g. DRM_FBDEV_EMULATION) do the same trick. So I guess
> 
> Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> 
> But really, is all this complexity?
> -Daniel
> 
>>
>> Regards,
>>
>> 	Hans
>>
>>> ---
>>> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
>>> index 1168351267fd..e8e478d6da9c 100644
>>> --- a/drivers/gpu/drm/Kconfig
>>> +++ b/drivers/gpu/drm/Kconfig
>>> @@ -163,6 +163,7 @@ config DRM_LOAD_EDID_FIRMWARE
>>>
>>>  config DRM_DP_CEC
>>>  	bool "Enable DisplayPort CEC-Tunneling-over-AUX HDMI support"
>>> +	depends on DRM
>>>  	select CEC_CORE
>>>  	help
>>>  	  Choose this option if you want to enable HDMI CEC support for
>>>
>>
>