Commits
Ville Syrjälä committed 8a292d016d1
drm/i915: Make RPS EI/thresholds multiple of 25 on SNB-BDW
Somehow my SNB GT1 (Dell XPS 8300) gets very unhappy around
GPU hangs if the RPS EI/thresholds aren't suitably aligned.
It seems like scheduling/timer interupts stop working somehow
and things get stuck eg. in usleep_range().
I bisected the problem down to
commit 8a5864377b12 ("drm/i915/skl: Restructured the gen6_set_rps_thresholds function")
I observed that before all the values were at least multiples of 25,
but afterwards they are not. And rounding things up to the next multiple
of 25 does seem to help, so lets' do that. I also tried roundup(..., 5)
but that wasn't sufficient. Also I have no idea if we might need this sort of
thing on gen9+ as well.
These are the original EI/thresholds:
LOW_POWER
GEN6_RP_UP_EI 12500
GEN6_RP_UP_THRESHOLD 11800
GEN6_RP_DOWN_EI 25000
GEN6_RP_DOWN_THRESHOLD 21250
BETWEEN
GEN6_RP_UP_EI 10250
GEN6_RP_UP_THRESHOLD 9225
GEN6_RP_DOWN_EI 25000
GEN6_RP_DOWN_THRESHOLD 18750
HIGH_POWER
GEN6_RP_UP_EI 8000
GEN6_RP_UP_THRESHOLD 6800
GEN6_RP_DOWN_EI 25000
GEN6_RP_DOWN_THRESHOLD 15000
These are after 8a5864377b12:
LOW_POWER
GEN6_RP_UP_EI 12500
GEN6_RP_UP_THRESHOLD 11875
GEN6_RP_DOWN_EI 25000
GEN6_RP_DOWN_THRESHOLD 21250
BETWEEN
GEN6_RP_UP_EI 10156
GEN6_RP_UP_THRESHOLD 9140
GEN6_RP_DOWN_EI 25000
GEN6_RP_DOWN_THRESHOLD 18750
HIGH_POWER
GEN6_RP_UP_EI 7812
GEN6_RP_UP_THRESHOLD 6640
GEN6_RP_DOWN_EI 25000
GEN6_RP_DOWN_THRESHOLD 15000
And these are what we have after this patch:
LOW_POWER
GEN6_RP_UP_EI 12500
GEN6_RP_UP_THRESHOLD 11875
GEN6_RP_DOWN_EI 25000
GEN6_RP_DOWN_THRESHOLD 21250
BETWEEN
GEN6_RP_UP_EI 10175
GEN6_RP_UP_THRESHOLD 9150
GEN6_RP_DOWN_EI 25000
GEN6_RP_DOWN_THRESHOLD 18750
HIGH_POWER
GEN6_RP_UP_EI 7825
GEN6_RP_UP_THRESHOLD 6650
GEN6_RP_DOWN_EI 25000
GEN6_RP_DOWN_THRESHOLD 15000
Cc: stable@vger.kernel.org
Cc: Akash Goel <akash.goel@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Testcase: igt/kms_pipe_crc_basic/hang-read-crc-pipe-B
Fixes: 8a5864377b12 ("drm/i915/skl: Restructured the gen6_set_rps_thresholds function")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1461159836-9108-1-git-send-email-ville.syrjala@linux.intel.com
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Patrik Jakobsson <patrik.jakobsson@linux.intel.com>