From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thierry Reding Subject: Re: [RFC 4/4] drm: Add NVIDIA Tegra support Date: Thu, 12 Apr 2012 15:25:31 +0200 Message-ID: <20120412132531.GC5353@avionic-0098.adnet.avionic-design.de> References: <1334146230-1795-1-git-send-email-thierry.reding@avionic-design.de> <1334146230-1795-5-git-send-email-thierry.reding@avionic-design.de> <4F85C97E.50203@wwwdotorg.org> <20120412092106.GU3852@pengutronix.de> <20120412093301.GB23336@avionic-0098.mockup.avionic-design.de> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============8544377842281880572==" Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Alex Deucher Cc: Stephen Warren , Sascha Hauer , dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org, linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, Colin Cross , Jon Mayo , devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org List-Id: devicetree@vger.kernel.org --===============8544377842281880572== Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="ABTtc+pdwF7KHXCz" Content-Disposition: inline --ABTtc+pdwF7KHXCz Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable * Alex Deucher wrote: > On Thu, Apr 12, 2012 at 5:33 AM, Thierry Reding > wrote: > > In other words I would like to use the Tegra hardware to render content= into > > a framebuffer (using potentially the 3D engine or HW accelerated video > > decoding blocks) but display that framebuffer with a CRTC registered by= a > > different driver (perhaps provided by a PCIe or USB device). > > > > I think such a setup would be possible if the CRTC registration can be > > decoupled from the DRM driver. Perhaps sdrm even supports that already? >=20 > You should be able to do something like that already with dma_buf and > the drm prime infrastructure. There's even a drm driver for the udl > USB framebuffer devices. Using DRM PRIME requires user-space to be involved. I was thinking more alo= ng the lines of allowing a dumb DRM driver that only provides a CRTC to regist= er with another driver so that it shows up as an output for the latter DRM device. Then again, having user-space control this may be more flexible. Performanc= e- wise both should be about the same, right? What I don't quite understand yet is how the DMABUF would be synchronized on both ends. Is there some infra- structure to account for it or would I have to export two buffers and flip them during the vblank of the "consumer"? Thierry --ABTtc+pdwF7KHXCz Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (GNU/Linux) iEYEARECAAYFAk+G18sACgkQZ+BJyKLjJp9yUgCfedk1cyQsdy4+JdUG6HydNLZM oToAniSdeVK4+piE/ghRhSQNk5zgSSHP =zPOZ -----END PGP SIGNATURE----- --ABTtc+pdwF7KHXCz-- --===============8544377842281880572== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ iommu mailing list iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org https://lists.linuxfoundation.org/mailman/listinfo/iommu --===============8544377842281880572==--