On Mon, May 30, 2011 at 9:45 PM, Tormod Volden wrote: > From: Tormod Volden <debian.tormod@xxxxxxxxx> > > Drivers using multiple framebuffers got broken by commit > 41c2e75e60200a860a74b7c84a6375c105e7437f which ignored the framebuffer > (or register) map offset when looking for existing maps. The rationale > was that the kernel-userspace ABI is fixed at a 32-bit offset, so the > real offsets could not always be handed over for comparison. > > Instead of ignoring the offset we will compare the lower 32 bit. Drivers > using multiple framebuffers should just make sure that the lower 32 bit > are different. The existing drivers in question are practically limited > to 32-bit systems so that should be fine for them. > > It is assumed that current drivers always specify a correct framebuffer > map offset, even if this offset was ignored since above commit. So this > patch should not change anything for drivers using only one framebuffer. > > Drivers needing multiple framebuffers with 64-bit map offsets will need > to cook up something, for instance keeping an ID in the lower bit which > is to be aligned away when it comes to using the offset. > > All of above applies to _DRM_REGISTERS as well. > > Signed-off-by: Tormod Volden <debian.tormod@xxxxxxxxx> > --- > > > On Mon, May 30, 2011 at 1:29 AM, Dave Airlie wrote: >> >> If you test it and it works I like it best. Simple and clear, and pretty >> close to what I was thinking was a good idea. >> >> As you say if someone needs this functionality in a new driver they can >> fix it, but really new drivers shouldn't be doing anything in this area. >> >> Dave. > > > Whoops, there was a less obvious fallthrough from the _DRM_SHM case above, > where we do not want to compare offsets at all if it contains a lock(*). > > This patch has been tested on savage, and for verification also on radeon > with DRI1 and DRI2. > > Tormod Hi Dave, Is this good to go now and I can expect to see it in e.g. drm-next or are there any issues or doubts? Cheers, Tormod _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
