linux_dsm_epyc7002/drivers/gpu
Ville Syrjälä 985b8bb486 drm/i915: Align DSPSURF to 128k on VLV/CHV
VLV/CHV have problems with 4k aligned linear scanout buffers. The VLV
docs got updated at some point to say that we need to align them to
128k, just like we do on gen4.

So far I've seen the problem manifest when the stride is an odd multiple
of 512 bytes, and the surface address meets the following pattern
'(addr & 0xf000) == 0x1000' (also == 0x2000 is problematic on VLV). The
result is a starcase effect (so some pages get dropped maybe?), with a
few pages here and there clearly getting scannout out at the wrong position.

I've not actually been able to reproduce this problem on gen4, so it's
not clear of the issue is any way related to the 128k restrictions
supposedly inherited from gen4. But let's hope the 128k alignment is
sufficient to hide it all.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Clint Taylor <Clinton.A.Taylor@intel.com>
Reviewed-by: Arun R Murthy <arun.r.murthy@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-06-15 18:07:27 +02:00
..
drm drm/i915: Align DSPSURF to 128k on VLV/CHV 2015-06-15 18:07:27 +02:00
host1x gpu: host1x: Export host1x_syncpt_read() 2015-04-02 18:46:20 +02:00
ipu-v3 imx-drm changes to use media bus formats and LDB drm_panel support 2015-04-13 17:28:57 +10:00
vga Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-10-13 16:23:15 +02:00
Makefile gpu: host1x: Provide a proper struct bus_type 2015-01-27 10:09:14 +01:00