[PATCH v2 xf86-video-amdgpu] Don't bail from drmmode_set_desired_modes immediately

[Michel Dänzer]

On 2018-02-16 03:18 PM, Harry Wentland wrote:
> On 2018-02-16 03:29 AM, Michel Dänzer wrote:
>> On 2018-02-15 10:05 PM, Harry Wentland wrote:
>>> On 2018-02-15 12:49 PM, Michel Dänzer wrote:
>>>> From: Michel Dänzer <michel.daenzer at amd.com>
>>>>
>>>> If we fail to find or set the mode for a CRTC, keep trying for the
>>>> remaining CRTCs, and only return FALSE if we failed for all CRTCs that
>>>> should be on.
>>>>
>>>> Signed-off-by: Michel Dänzer <michel.daenzer at amd.com>
>>>
>>> Thanks. This should help when bandwidth checks in DC fail.
>>
>> It might in some cases, though I'm afraid it won't make any difference
>> in the case you're probably thinking of (not enough bandwidth for 3 4K
>> monitors connected to an APU), in that case two monitors should light up
>> either way. But if there was e.g. a fourth 1080 monitor connected, that
>> might light up now, whereas it might not have before.
>>
> 
> Are you saying that if 3 @ 4k60 fail DDX or X will retry at lower refresh rate for one (or all CRTCs)?

That's not what I'm saying. Such a fallback would be more complicated,
and might require changing Xorg code. I'm currently not planning to work
on that.

drmmode_set_desired_modes simply tries setting the mode chosen by Xorg
for each CRTC in turn. Before this change, if setting the mode failed
for any CRTC, it would bail and wouldn't even try setting the mode for
the remaining CRTCs. With this change, it will continue trying to set
the modes for the remaining CRTCs.


-- 
Earthling Michel Dänzer               |               http://www.amd.com
Libre software enthusiast             |             Mesa and X developer