[Mesa-dev] [PATCH v1 0/7] Implement commont gralloc_handle_t in libdrm

[Tomasz Figa]

On Fri, Mar 23, 2018 at 8:52 PM, Robert Foss <robert.foss at collabora.com> wrote:
> Hey Chih-Wei,
>
>
> On 03/23/2018 03:43 AM, Chih-Wei Huang wrote:
>>
>> 2018-03-22 16:23 GMT+08:00 Tomasz Figa <tfiga at chromium.org>:
>>>
>>> Hi Chih-Wei,
>>>
>>> On Thu, Feb 22, 2018 at 2:53 PM, Chih-Wei Huang <cwhuang at linux.org.tw>
>>> wrote:
>>>>
>>>> 2018-02-21 3:03 GMT+08:00 Rob Herring <robh at kernel.org>:
>>>>>
>>>>>
>>>>> Perhaps worth revisiting. Given we've failed to progress at all since
>>>>> then may change opinions some. We already have to handle multiple
>>>>> opens share the same pipe_screen, so I don't think reusing the fd buys
>>>>> us anything.
>>>>>
>>>>> Maybe we're close to the point of removing the flink name support too.
>>>>> The android-x86 folks have been working to get dma-bufs working.
>>>>> Chih-Wei, any comments on this?
>>>>
>>>>
>>>> Ah! Sorry. I didn't catch or understand the details.
>>>> Did you mean the attempts to use drm_hwcomposer
>>>> in android-x86?
>>>> My understanding so far is most x86 GPUs won't work
>>>> except some very limited models.
>>>> It's due to kernel driver issues which may never be solved.
>>>> So we can't drop the flink name support.
>>>> Please correct me if I am wrong.
>>>
>>>
>>> Could you elaborate a bit more on those GPUs that won't work and
>>> corresponding driver issues? We're running cros_gralloc on Intel and
>>> AMD GPUs, with DMA-buf and render-node only setup and we haven't seen
>>> any problems.
>>
>>
>> Hi Tomasz,
>> I remember (in our previous discussion) you said
>> CrOS uses your own hwcomposer (proprietary?) so
>> the story may be different.
>>
>> What we have tried is gbm_gralloc + drm_hwcomposer
>> and I reported the issues here:
>>
>> https://lists.freedesktop.org/archives/dri-devel/2017-September/153580.html
>
>
> I took the liberty of moving you nouveau issue into the drm_hwc gitlab
> bugtracker.
>
> https://gitlab.freedesktop.org/drm-hwcomposer/drm-hwcomposer/issues/1

Hmm, reading further in that thread, that seemed to be related to
missing nouveau.atomic=1 in kernel command line:
https://lists.freedesktop.org/archives/dri-devel/2017-September/153681.html

It went further, but didn't work very well. I suspect that could have
been related to DRM_GRALLOC_GET_FD being used, which makes the mess
from the system due to gralloc and Mesa stepping on each other's GEM
handles (which aren't reference counted by design and importing a
buffer several time will always return the same handle).

Best regards,
Tomasz