2011/8/10 Michel D?nzer <michel at daenzer.net>: > On Die, 2011-08-09 at 23:52 +0530, Mayank Rungta wrote: >> Added a check for the radeon ring buffer write index in r600.c which >> reads 0xffffffff on resume. This results in an Oops during >> radeon_ring_write. Masking the value averts this. >> >> This problem is not seen to be fixed in 3.0 r600.c as well. >> >> Detailed analysis of the problem can be found at - >> >> https://bugs.launchpad.net/ubuntu/+source/linux/+bug/820746/ >> >> --- >> >> BUG: unable to handle kernel paging request at fa501ffc - Oops at >> r600_cp_start+0x48/0x380 in r600_cp_resume+0x345/0x580 [radeon] >> >> drivers/gpu/drm/radeon/r600.c >> >> >> >> --- linux-2.6.38/drivers/gpu/drm/radeon/r600.c.orig ? ?2011-08-05 >> 15:39:40.824612700 +0530 >> +++ linux-2.6.38/drivers/gpu/drm/radeon/r600.c ? ?2011-08-08 >> 05:29:21.744417857 +0530 >> @@ -2218,6 +2218,8 @@ int r600_cp_resume(struct radeon_device >> >> ? ? ? rdev->cp.rptr = RREG32(CP_RB_RPTR); >> ? ? ? rdev->cp.wptr = RREG32(CP_RB_WPTR); >> + ? ?/* protect against crazy HW on resume */ >> + ? ?rdev->cp.wptr &= rdev->cp.ptr_mask; > > The indentation of the lines you're adding doesn't match the surrounding > lines. > > > Although the same workaround is already in r100.c, I wonder if we > shouldn't rather try and eliminate all reads from the CP_RB_WPTR > register, at least other than for debugging purposes. Alex, what do you > think?
Either this or reset the registers to 0 or a saved value on resume rather than reading from them. > > Otherwise, this should probably be added in evergreen.c as well. > Yes, and ni.c as well. Alex > >> ? ? ? ? ?Developer's Certificate of Origin 1.1 >> >> ? ? ? ? ?[...] > > No need to include all this text, just the *-by: tags are enough. > > > -- > Earthling Michel D?nzer ? ? ? ? ? | ? ? ? ? ? ? ? ? ? http://www.amd.com > Libre software enthusiast ? ? ? ? | ? ? ? ? ?Debian, X and DRI developer > _______________________________________________ > dri-devel mailing list > dri-devel at lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/dri-devel >