Re: [patch] radeonfb: FB_WAITFORVSYNC implementation
From: Michel Dänzer <hidden>
Date: 2005-03-12 19:20:36
On Sat, 2005-03-12 at 17:12 +0000, Torgeir Veimo wrote:
On Sat, 2005-03-12 at 12:10 -0500, Michel D채nzer wrote:quoted
On Sat, 2005-03-12 at 17:13 +0200, Ville Syrj채l채 wrote:quoted
Also adding support for FB_ACTIVATE_VBL should be quite simple now.You don't need an interrupt for that. You can choose via the CRTC_OFFSET_CNTL:CRTC_OFFSET_FLIP_CNTL bit whether the update of the CRTC offset should take effect immediately or on the next vertical blank. Personally, I'm not sure why something that needs this functionality can't use the DRM...My interest for adding this is video playback. It's kind of hard to do through the DRM.
You don't have to use the DRM for anything but the wait for vsync; I can see the effort of initializing the DRM to the point where this is possible being prohibitive though. The real point is that the usage of the interrupt needs to be coordinated between the framebuffer device and the DRM. Something like the first one to request the IRQ setting up a callback mechanism where the other can hook into might be a possibility? Or the shared mini-driver that has been proposed for years, but isn't liked by some... -- Earthling Michel D채nzer | Debian (powerpc), X and DRI developer Libre software enthusiast | http://svcs.affero.net/rm.php?r=daenzer ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_ide95&alloc_id396&op=click