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From: Daniel Vetter <daniel@ffwll.ch>
To: "Kristian Høgsberg" <krh@bitplanet.net>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>,
	"intel-gfx@lists.freedesktop.org"
	<intel-gfx@lists.freedesktop.org>,
	stable@vger.kernel.org
Subject: Re: [PATCH] drm/i915: Deny wrapping an userptr into a framebuffer
Date: Fri, 23 Oct 2015 10:04:24 +0200	[thread overview]
Message-ID: <20151023080424.GJ16848@phenom.ffwll.local> (raw)
In-Reply-To: <CAOeoa-eQOzhZKHeCYi55MKyuberuupWvPt2PGAxbP6nDqH-_Ew@mail.gmail.com>

On Thu, Oct 22, 2015 at 04:23:09PM -0700, Kristian Høgsberg wrote:
> On Tue, Oct 13, 2015 at 6:22 AM, Chris Wilson <chris@chris-wilson.co.uk> wrote:
> > Pinning a userptr onto the hardware raises interesting questions about
> > the lifetime of such a surface as the framebuffer extends that life
> > beyond the client's address space. That is the hardware will need to
> > keep scanning out from the backing storage even after the client wants
> > to remap its address space. As the hardware pins the backing storage,
> > the userptr becomes invalid and this raises a WARN when the clients
> > tries to unmap its address space. The situation can be even more
> > complicated when the buffer is passed between processes, between a
> > client and display server, where the lifetime and hardware access is
> > even more confusing. Deny it.
> 
> Can we allow this for unsynchronized userptrs?

I'd like to not add more complexity to a root-only feature.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/intel-gfx

WARNING: multiple messages have this Message-ID (diff)
From: Daniel Vetter <daniel@ffwll.ch>
To: "Kristian Høgsberg" <krh@bitplanet.net>
Cc: Chris Wilson <chris@chris-wilson.co.uk>,
	"intel-gfx@lists.freedesktop.org"
	<intel-gfx@lists.freedesktop.org>,
	Daniel Vetter <daniel.vetter@ffwll.ch>,
	stable@vger.kernel.org
Subject: Re: [Intel-gfx] [PATCH] drm/i915: Deny wrapping an userptr into a framebuffer
Date: Fri, 23 Oct 2015 10:04:24 +0200	[thread overview]
Message-ID: <20151023080424.GJ16848@phenom.ffwll.local> (raw)
In-Reply-To: <CAOeoa-eQOzhZKHeCYi55MKyuberuupWvPt2PGAxbP6nDqH-_Ew@mail.gmail.com>

On Thu, Oct 22, 2015 at 04:23:09PM -0700, Kristian H�gsberg wrote:
> On Tue, Oct 13, 2015 at 6:22 AM, Chris Wilson <chris@chris-wilson.co.uk> wrote:
> > Pinning a userptr onto the hardware raises interesting questions about
> > the lifetime of such a surface as the framebuffer extends that life
> > beyond the client's address space. That is the hardware will need to
> > keep scanning out from the backing storage even after the client wants
> > to remap its address space. As the hardware pins the backing storage,
> > the userptr becomes invalid and this raises a WARN when the clients
> > tries to unmap its address space. The situation can be even more
> > complicated when the buffer is passed between processes, between a
> > client and display server, where the lifetime and hardware access is
> > even more confusing. Deny it.
> 
> Can we allow this for unsynchronized userptrs?

I'd like to not add more complexity to a root-only feature.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

  reply	other threads:[~2015-10-23  8:04 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-10-13 13:22 [PATCH] drm/i915: Deny wrapping an userptr into a framebuffer Chris Wilson
2015-10-13 14:00 ` [Intel-gfx] " Tvrtko Ursulin
2015-10-13 14:04   ` Tvrtko Ursulin
2015-10-13 14:04     ` [Intel-gfx] " Tvrtko Ursulin
2015-10-13 14:08   ` Jani Nikula
2015-10-13 15:29   ` Daniel Vetter
2015-10-13 15:29     ` [Intel-gfx] " Daniel Vetter
2015-10-22 23:23 ` Kristian Høgsberg
2015-10-23  8:04   ` Daniel Vetter [this message]
2015-10-23  8:04     ` Daniel Vetter
2015-10-23  9:28     ` Chris Wilson
2015-10-23  9:28       ` Chris Wilson
2015-10-23 19:20       ` Kristian Høgsberg
  -- strict thread matches above, loose matches on Subject: below --
2015-10-13 13:18 Chris Wilson

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