Device enumeration support in libdrm

[Emil Velikov]

Dropping dri-devel for a second.

Hi Jammy,

On 10 July 2015 at 18:56, Emil Velikov <emil.l.velikov at gmail.com> wrote:
> On 9 July 2015 at 03:26, Zhou, Jammy <Jammy.Zhou at amd.com> wrote:
>> Although I don't like the method of manually iterating sysfs, it seems the last resort if we want to avoid introducing libudev dependency.
>>
> I have the same feeling, so if anyone can come with an better solution
> I'm all ears.
>
>> Besides, you mentioned that you would spend some time on the device enumeration interface, do you have some chance to look at it?
>>
> Not really bth. Waiting for a month someone to ack the revert inspired
> me to push this at the bottom on my list. Now that there is some
> interest I'll bring it back up.
>
I've been looking at this over the last few days, aiming for a
compatible solution and it has been proving a bit annoying. Mostly due
to the way any platform devices interact with the UNIQUE ioctls.

Namely the goal is to have drmGetDevices() provide bus information
that can be used with conjunction with drmOpen and (optionally)
drmGetBusid.

Can you help me out, understand how you're going to be using this,
such that I don't butcher things.
In what formal should the bus information be - are your intentions
solely on feeding that to drmOpen() or is the user going to do
something with it ?

Would providing the vendor/device id (via drmGetDevices) suffice or
you guys need the sub{vendor,device} rev as well ?


Thanks
Emil