On 22.01.2015 18:28, Michel Dänzer wrote: > On 22.01.2015 18:08, Christian König wrote: >> Am 22.01.2015 um 08:31 schrieb Michel Dänzer: >>> On 21.01.2015 18:22, Christian König wrote: >>>> Am 21.01.2015 um 09:36 schrieb Michel Dänzer: >>>>> From: Michel Dänzer <michel.daenzer@xxxxxxx> >>>>> >>>>> The GART table BO has to be moved out of VRAM for suspend/resume. Any >>>>> updates to the GART table during that time were silently dropped >>>>> without >>>>> this change. This caused GPU lockups on resume in some cases, see >>>>> the bug >>>>> reports referenced below. >>>>> >>>>> This might also make GPU reset more robust in some cases, as we no >>>>> longer >>>>> rely on the GART table in VRAM being preserved across the GPU >>>>> lockup/reset. >>>>> >>>>> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=85204 >>>>> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=86267 >>>>> Cc: stable@xxxxxxxxxxxxxxx >>>>> Signed-off-by: Michel Dänzer <michel.daenzer@xxxxxxx> >>>> Can we make that directly part of radeon_gart_table_vram_pin? Doesn't >>>> seem to make sense to always need to call both functions. >>> Good point, fixed in v2. >>> >>> >>>> Additional to that couldn't we just stop mapping/unmapping the BO in >>>> radeon_gart_table_vram_pin? As far as I know CPU mapped BOs can still >>>> move around. >>> You're probably thinking of userspace mappings. I think the kernel >>> mapping would continue pointing to the same area of VRAM even while the >>> BO is evicted from VRAM or pinned back to another area of VRAM. >> >> >> Oh really? I was always under the impression that we only need to wait >> for moves to complete and the kernel page tables would point to the new >> location after that automatically. >> >> If that's not the case we might have a problem in the UVD code as well. > > AFAIK it's not the case. If you can't confirm it either way from looking > at the TTM code, maybe you can hack up a test to verify it? Actually, I think I already tested it a couple of years ago, when I tried un-pinning the fbdev BO while it's not being scanned out. I could see fbcon scribbling over other BOs in VRAM when there was console output. :) -- Earthling Michel Dänzer | http://www.amd.com Libre software enthusiast | Mesa and X developer _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
