[PATCH 2/2] drm/amdgpu: Add modeset module option

[Christian König]

Am 03.04.2018 um 11:29 schrieb Daniel Vetter:
> On Sun, Apr 01, 2018 at 10:12:10PM +0200, Christian König wrote:
>> Am 01.04.2018 um 20:21 schrieb Takashi Iwai:
>> [SNIP]
>> Well exactly that's the point, nothing.
>>
>> The problem is that the option name is confusing to the end user because the
>> expectation is that "nomodeset" just means that they only can't change the
>> display mode.
>>
>> Some (unfortunately quite a lot) people don't realize that for KMS drivers
>> this means that the driver isn't even loaded and they also don't get any
>> acceleration.
>>
>> We had to explain that numerous times now. I think it would be best to give
>> the option a more meaningful name.
> Yeah, agreed with Christian. If we want a generic "pls disable all gfx
> accel" knob then probably best to put that into the drm core. And just
> outright fail loading the drm core if that happens, which will prevent all
> gfx drivers from loading.
>
> That likely means a hole bunch of stuff won't work (usually sound keels
> over too), but that's what you get for this. Only disabling modesetting
> without disabling the entire driver doesn't work (never has, except for
> this UMS+GEM combo only i915 support, and not for long).
>
> And once we have that knob, probably best to phase out all the per-driver
> options.

+ some compability code to keep "nomodeset" working for a while longer 
and printing a warning that the option is deprecated.

If we approach it like that the whole idea sounds rather reasonable to me.

Christian.

> -Daniel
>