Re: [Intel-gfx] [PATCH 1/2] drm/i915: Disallow pin ioctl completely for kms drivers

[Jesse Barnes <jbarnes@virtuousgeek.org>]

On 11/24/2014 06:13 AM, Chris Wilson wrote:
> On Mon, Nov 24, 2014 at 03:10:05PM +0100, Daniel Vetter wrote:
>> On Mon, Nov 24, 2014 at 10:35:29AM +0000, Chris Wilson wrote:
>>> Pinning is a useful tool and it would also be useful to have again on
>>> gen6+.
>>
>> I think softpin or similar is doable with ppgtt. But with shared ggtt I'm
>> not really enthusiastic about providing this kind of rope to userspace.
>> And softpin is a different type of pinning, so we don't really lose
>> anything by ripping out the userspace hard pinning ioctls.
> 
> I am not talking about softpin, but being able to pin memory and a GGTT
> binding itself is useful.

I see you merged this over Chris's objections and then shot down his
revert.  I'm not clear on why you're so opposed to the pin ioctl?  It's
a privileged op and definitely has its uses as Chris has repeatedly
pointed out.

Why so insistent on dropping this particular ioctl?  Do you see it
causing actual problems?  Or do you just like preventing userspace from
doing things you don't agree with?

(Sorry, catching up on ancient backlog from intel-gfx, so maybe there's
a thread I missed when re-looking at this.  If so, please point me at it.)

Thanks,
Jesse