On Wed, Feb 22, 2012 at 10:24 AM, Daniel Vetter <daniel@xxxxxxxx> wrote: > On Wed, Feb 22, 2012 at 04:03:21PM +0000, James Simmons wrote: >> >> > > Imo we should ditch this - fb accel doesn't belong into the kernel. Even >> > > on hw that still has a blitter for easy 2d accel without a complete 3d >> > > state setup necessary, it's not worth it. Chris Wilson from our team once >> > > played around with implementing fb accel in the kernel (i915 hw still has >> > > a blitter engine in the latest generations). He quickly noticed that to >> > > have decent speed, competitive with s/w rendering by the cpu he needs the >> > > entire batch and buffer management stuff from userspace. And to really >> > > beat the cpu, you need even more magic. >> > > >> > > If you want fast 2d accel, use something like cairo. >> > >> > Our conclusion on this is that we should not expose an explicit 2D >> > acceleration API at the kernel level. If really needed, hardware 2D >> > acceleration could be implemented as a DRM device to handle memory management, >> > commands ring setup, synchronization, ... but I'm not even sure if that's >> > worth it. I might not have conveyed it well in my notes. >> >> Fbcon scrolling at be painful at HD or better modes. Fbcon needs 3 >> possible accels; copyarea, imageblit, and fillrect. The first two could be >> hooked from the TTM layer. Its something I plan to experiment to see if >> its worth it. > > Let's bite into this ;-) I know that fbcon scrolling totally sucks on big > screens, but I also think it's a total waste of time to fix this. Imo > fbcon has 2 use-cases: > - display an OOSP. > - allow me to run fsck (or any other desaster-recovery stuff). > > It can do that quite fine already. and for just fbcon scrolling, if you really wanted to you could implement it by just shuffling pages around in a GART.. (although, someone, *please* re-write fbcon) BR, -R > Flamy yours, Daniel > -- > Daniel Vetter > Mail: daniel@xxxxxxxx > Mobile: +41 (0)79 365 57 48 > -- > To unsubscribe from this list: send the line "unsubscribe linux-media" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
