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| author | Matthew Brost <matthew.brost@intel.com> | 2024-10-23 15:12:00 -0700 |
|---|---|---|
| committer | Lucas De Marchi <lucas.demarchi@intel.com> | 2024-10-30 22:14:06 -0700 |
| commit | 5a710196883e0ac019ac6df2a6d79c16ad3c32fa (patch) | |
| tree | c19ffc891b142788e6fb556abfdb9847a84e3d2b /drivers/gpu | |
| parent | 0191fddf53748cf2b473d78faeabe6dcb47689d2 (diff) | |
| download | lwn-5a710196883e0ac019ac6df2a6d79c16ad3c32fa.tar.gz lwn-5a710196883e0ac019ac6df2a6d79c16ad3c32fa.zip | |
drm/xe: Add mmio read before GGTT invalidate
On LNL without a mmio read before a GGTT invalidate the GuC can
incorrectly read the GGTT scratch page upon next access leading to jobs
not getting scheduled. A mmio read before a GGTT invalidate seems to fix
this. Since a GGTT invalidate is not a hot code path, blindly do a mmio
read before each GGTT invalidate.
Cc: John Harrison <John.C.Harrison@Intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: stable@vger.kernel.org
Fixes: dd08ebf6c352 ("drm/xe: Introduce a new DRM driver for Intel GPUs")
Reported-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/3164
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241023221200.1797832-1-matthew.brost@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/xe/xe_ggtt.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/gpu/drm/xe/xe_ggtt.c b/drivers/gpu/drm/xe/xe_ggtt.c index 0124ad120c04..558fac8bb6fb 100644 --- a/drivers/gpu/drm/xe/xe_ggtt.c +++ b/drivers/gpu/drm/xe/xe_ggtt.c @@ -401,6 +401,16 @@ static void ggtt_invalidate_gt_tlb(struct xe_gt *gt) static void xe_ggtt_invalidate(struct xe_ggtt *ggtt) { + struct xe_device *xe = tile_to_xe(ggtt->tile); + + /* + * XXX: Barrier for GGTT pages. Unsure exactly why this required but + * without this LNL is having issues with the GuC reading scratch page + * vs. correct GGTT page. Not particularly a hot code path so blindly + * do a mmio read here which results in GuC reading correct GGTT page. + */ + xe_mmio_read32(xe_root_tile_mmio(xe), VF_CAP_REG); + /* Each GT in a tile has its own TLB to cache GGTT lookups */ ggtt_invalidate_gt_tlb(ggtt->tile->primary_gt); ggtt_invalidate_gt_tlb(ggtt->tile->media_gt); |