[Mesa-dev] [PATCH v2] intel: Move the DRM uapi headers to a non-Intel location.

[Alex Deucher]

On Fri, Jun 30, 2017 at 12:40 PM, Lionel Landwerlin
<lionel.g.landwerlin at intel.com> wrote:
> On 30/06/17 17:14, Alex Deucher wrote:
>>
>> On Fri, Jun 30, 2017 at 12:02 PM, Eric Anholt <eric at anholt.net> wrote:
>>>
>>> Alex Deucher <alexdeucher at gmail.com> writes:
>>>
>>>> On Thu, Jun 29, 2017 at 11:42 AM, Eric Anholt <eric at anholt.net> wrote:
>>>>>
>>>>> I want to remove vc4's dependency on headers from libdrm as well, but
>>>>> storing multiple copies of drm_fourcc.h in our tree would be silly.
>>>>>
>>>>> v2: Update Android.mk as well, move distcheck drm*.h references to
>>>>>      top-level noinst_HEADERS.
>>>>>
>>>>> Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin at intel.com>
>>>>> Reviewed-by: Daniel Stone <daniels at collabora.com>
>>>>> ---
>>>>>   Makefile.am                                      |  4 ++++
>>>>>   {src/intel/drm => include/drm-uapi}/README       |  0
>>>>>   {src/intel/drm => include/drm-uapi}/drm.h        |  0
>>>>>   {src/intel/drm => include/drm-uapi}/drm_fourcc.h |  0
>>>>>   {src/intel/drm => include/drm-uapi}/drm_mode.h   |  0
>>>>>   {src/intel/drm => include/drm-uapi}/i915_drm.h   |  0
>>>>>   src/intel/Android.vulkan.mk                      |  2 +-
>>>>>   src/intel/Makefile.am                            |  1 -
>>>>>   src/intel/Makefile.drm.am                        | 22
>>>>> ----------------------
>>>>>   src/intel/Makefile.sources                       |  6 ------
>>>>>   src/intel/Makefile.vulkan.am                     |  2 +-
>>>>>   src/mesa/drivers/dri/i965/Android.mk             |  4 ++--
>>>>>   src/mesa/drivers/dri/i965/Makefile.am            |  2 +-
>>>>>   13 files changed, 9 insertions(+), 34 deletions(-)
>>>>>   rename {src/intel/drm => include/drm-uapi}/README (100%)
>>>>>   rename {src/intel/drm => include/drm-uapi}/drm.h (100%)
>>>>>   rename {src/intel/drm => include/drm-uapi}/drm_fourcc.h (100%)
>>>>>   rename {src/intel/drm => include/drm-uapi}/drm_mode.h (100%)
>>>>>   rename {src/intel/drm => include/drm-uapi}/i915_drm.h (100%)
>>>>>   delete mode 100644 src/intel/Makefile.drm.am
>>>>
>>>>
>>>> I don't mean to pick on this patch specifically, but maybe it would
>>>> still make sense to depend on libdrm for the drm headers?  If not do
>>>> we want similar restrictions on updating these as we have for libdrm?
>>>
>>> Yes, we certainly have the same restrictions on updating headers (pull
>>> only things that have landed in airlied's drm-next, or possibly
>>> drm-misc-next if acked by airlied) as libdrm does.  That's
>>> "participating in kernel DRM development" rules, not libdrm rules.
>>
>> I'm not arguing about the fact that stuff has to land in drm-next,
>> etc. first, but there are pretty strict additional requirements as to
>> how they are updated:
>> https://cgit.freedesktop.org/mesa/drm/tree/include/drm/README
>> Do we want to enforce similar requirements in mesa?
>
>
> I think that's the idea, and what's in the README file of this commit.
> Maybe we need to update to to actually put the url of airlied's tree?
>
>>
>>> I don't think it makes sense to depend on libdrm if all you're using
>>>  From libdrm is the header that you can just put in the tree.
>>
>> I though we agreed that libdrm was supposed to be the canonical source
>> for these headers in userspace.  It just seems like we are going to
>> end up with a proliferation of these headers as various projects
>> decide to include them directly.
>
>
> I guess most driver developers didn't have an opinion at the time or didn't
> pay attention to the patch introducing
> https://cgit.freedesktop.org/mesa/drm/tree/include/drm/README
>
> Here is a pointer to the discussion with a different set of people, with
> Eric's answer which makes the best argument for this (in my opinion) :
>
> https://lists.freedesktop.org/archives/mesa-dev/2017-May/154491.html

I don't necessarily agree with the rules for updating the headers in
libdrm.  I agree with Eric's statement that they should always be
compatible.  I like to be able to update the UAPI headers along with
the libdrm patch that uses them.  That said, I get yelled at every
time I try and do that, so I feel like we should apply that equally or
get rid of it.

Alex