[Mesa-dev] Removing GRALLOC_MODULE_PERFORM_GET_DRM_FD

[Tomasz Figa]

On Mon, Mar 26, 2018 at 9:45 PM, Robert Foss <robert.foss at collabora.com> wrote:
> Hey,
>
> On 03/23/2018 06:21 PM, Emil Velikov wrote:
>>
>> On 23 March 2018 at 16:20, Tomasz Figa <tfiga at chromium.org> wrote:
>>>
>>> On Sat, Mar 24, 2018 at 12:55 AM, Emil Velikov <emil.l.velikov at gmail.com>
>>> wrote:
>>>>
>>>> On 23 March 2018 at 13:15, Tomasz Figa <tfiga at chromium.org> wrote:
>>>>
>>>>>
>>>>> Perhaps we could try to use drmOpenWithType() [2]. We could have one
>>>>> property that would be passed as "name" argument and another property
>>>>> for "busid" argument. I assume "type" would be always RENDER?
>>>>>
>>>> I would strongly encourage against using the drmOpen* API, it's a DRI1
>>>> remnant.
>>>> It might work in a particular instance, but has a number of serious
>>>> flaws. Some highlights:
>>>>   - using busid works only with PCI devices
>>>>   - open() w/o O_CLOEXEC
>>>>   - when build w/o udev - it creates a node: mkdir, chown(root), chmod,
>>>> mknod
>>>>   - calls back into Xserver/DDX module
>>>>   - last but no least - borderline hacks with massive documentation [1]
>>>> to keep this running.
>>>
>>>
>>> I wasn't aware of that. Thanks for pointing this out.
>>>
>>> Still, I think matching by name and/or bus ID would make sense,
>>> wouldn't it? Perhaps Mesa already has some helpers for that?
>>>
>> Indeed it does make sense. AFAICT there's no such helper - yet no
>> objections to adding one ;-)
>
>
> So, I guess having one would be helpful.
> Where should it live, and what should it be built ontop of?

There is some code of similar purpose in src/loader/loader.c, e.g.
loader_open_device(). Emil, does it sound like a reasonable place?

Best regards,
Tomasz