[PATCH] drm: add drm device name

Christian König ckoenig.leichtzumerken at gmail.com
Tue Sep 17 11:20:09 UTC 2019


Am 17.09.19 um 11:27 schrieb Michel Dänzer:
> On 2019-09-17 11:23 a.m., Michel Dänzer wrote:
>> On 2019-09-17 10:23 a.m., Koenig, Christian wrote:
>>> Am 17.09.19 um 10:17 schrieb Daniel Vetter:
>>>> On Tue, Sep 17, 2019 at 10:12 AM Christian König
>>>> <ckoenig.leichtzumerken at gmail.com> wrote:
>>>>> Am 17.09.19 um 07:47 schrieb Jani Nikula:
>>>>>> On Mon, 16 Sep 2019, Marek Olšák <maraeo at gmail.com> wrote:
>>>>>>> The purpose is to get rid of all PCI ID tables for all drivers in
>>>>>>> userspace. (or at least stop updating them)
>>>>>>>
>>>>>>> Mesa common code and modesetting will use this.
>>>>>> I'd think this would warrant a high level description of what you want
>>>>>> to achieve in the commit message.
>>>>> And maybe explicitly call it uapi_name or even uapi_driver_name.
>>>> If it's uapi_name, then why do we need a new one for every generation?
>>>> Userspace drivers tend to span a lot more than just 1 generation. And
>>>> if you want to have per-generation data from the kernel to userspace,
>>>> then imo that's much better suited in some amdgpu ioctl, instead of
>>>> trying to encode that into the driver name.
>>> Well we already have an IOCTL for that, but I thought the intention here
>>> was to get rid of the PCI-ID tables in userspace to figure out which
>>> driver to load.
>> That's just unrealistic in general, I'm afraid. See e.g. the ongoing
>> transition from i965 to iris for recent Intel hardware. How is the
>> kernel supposed to know which driver is to be used?

Well how is userspace currently handling that? The kernel should NOT say 
which driver to use in userspace, but rather which one is used in the 
kernel.

Mapping that information to an userspace driver still needs to be done 
somewhere else, but the difference is that you don't need to add all 
PCI-IDs twice.

Christian.

>>
>>
>> For the Xorg modesetting driver, there's a simple solution, see
>> https://gitlab.freedesktop.org/xorg/xserver/merge_requests/278 .
>> Something similar can probably be done in Mesa as well.
> Another possibility might be for Xorg to use
> https://www.khronos.org/registry/EGL/extensions/MESA/EGL_MESA_query_driver.txt
> to determine the driver name. Then only Mesa might need any HW specific
> code.
>
>



More information about the dri-devel mailing list