Am 06.02.19 um 18:23 schrieb Ard Biesheuvel:
On Fri, 25 Jan 2019 at 11:35, Ard Biesheuvel ard.biesheuvel@linaro.org wrote:
On Fri, 25 Jan 2019 at 12:30, Christian König ckoenig.leichtzumerken@gmail.com wrote:
Am 25.01.19 um 09:43 schrieb Ard Biesheuvel:
On Thu, 24 Jan 2019 at 15:01, Alex Deucher alexdeucher@gmail.com wrote:
On Thu, Jan 24, 2019 at 9:00 AM Ard Biesheuvel ard.biesheuvel@linaro.org wrote:
On Thu, 24 Jan 2019 at 13:31, Koenig, Christian Christian.Koenig@amd.com wrote: > Am 24.01.19 um 13:06 schrieb Ard Biesheuvel: >> The DRM driver stack is designed to work with cache coherent devices >> only, but permits an optimization to be enabled in some cases, where >> for some buffers, both the CPU and the GPU use uncached mappings, >> removing the need for DMA snooping and allocation in the CPU caches. >> >> The use of uncached GPU mappings relies on the correct implementation >> of the PCIe NoSnoop TLP attribute by the platform, otherwise the GPU >> will use cached mappings nonetheless. On x86 platforms, this does not >> seem to matter, as uncached CPU mappings will snoop the caches in any >> case. However, on ARM and arm64, enabling this optimization on a >> platform where NoSnoop is ignored results in loss of coherency, which >> breaks correct operation of the device. Since we have no way of >> detecting whether NoSnoop works or not, just disable this >> optimization entirely for ARM and arm64. >> >> Cc: Christian Koenig christian.koenig@amd.com >> Cc: Alex Deucher alexander.deucher@amd.com >> Cc: David Zhou David1.Zhou@amd.com >> Cc: Huang Rui ray.huang@amd.com >> Cc: Junwei Zhang Jerry.Zhang@amd.com >> Cc: Michel Daenzer michel.daenzer@amd.com >> Cc: David Airlie airlied@linux.ie >> Cc: Daniel Vetter daniel@ffwll.ch >> Cc: Maarten Lankhorst maarten.lankhorst@linux.intel.com >> Cc: Maxime Ripard maxime.ripard@bootlin.com >> Cc: Sean Paul sean@poorly.run >> Cc: Michael Ellerman mpe@ellerman.id.au >> Cc: Benjamin Herrenschmidt benh@kernel.crashing.org >> Cc: Will Deacon will.deacon@arm.com >> Cc: Christoph Hellwig hch@infradead.org >> Cc: Robin Murphy robin.murphy@arm.com >> Cc: amd-gfx list amd-gfx@lists.freedesktop.org >> Cc: dri-devel dri-devel@lists.freedesktop.org >> Reported-by: Carsten Haitzler Carsten.Haitzler@arm.com >> Signed-off-by: Ard Biesheuvel ard.biesheuvel@linaro.org > The subject line should probably read "disable uncached...". > Ugh, of course ...
> With that fixed the patch is Reviewed-by: Christian König > christian.koenig@amd.com. >
Same: Reviewed-by: Alex Deucher alexander.deucher@amd.com
Thanks all
Should I resend the patch with the subject corrected?
I will update the subject line and push it upstream through drm-misc-next if nobody objects.
Wonderful, thanks.
Hi Christian,
Are you still planning to merge this for v5.1?
My bad, only pushed this to our internal branch, but forgot out drm-misc-next.
Fixed now, thanks for the reminder.
Christian.
Thanks, Ard. _______________________________________________ amd-gfx mailing list amd-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/amd-gfx