[PATCH xserver 0/6] modesetting: add DRI2 page flip support

[Emil Velikov]

On 19 August 2016 at 03:09, Michel Dänzer <michel at daenzer.net> wrote:
> On 19/08/16 11:02 AM, Yu, Qiang wrote:
>>
>> Each point of the patch set is not broken. Patches are arranged like
>> this to show how I do it:
>> 1. create a pageflip.c to host common page flip code
>> 2. copy amdgpu DDX DRI2 page flip code to modesetting dri2.c
>> 3. merge common DRI2 and present page flip code to pageflip.c
>>
>> Patch 4 is not a fix for broken code, just a commit from amdgpu DDX
>> to prevent present and DRI2 from flipping at the same time.
>
> This does mean though that if one has only up to patch 3 applied (e.g.
> during a bisection), one is exposed to the issues fixed by patch 4. So
> maybe patch 4 should be squashed into patch 3.
>
Precisely what I meant with "broken" - new code introduces a
functionality which conflicts with existing one.

And yes, one can see the code flow (and that it's partially copied
from amdgpu/ati) As-is the series brings unnecessary churn, since it
adds new code only to (re)move it.
Something many developers/projects consider a bad way to split patches.

Thanks
Emil