diff options
| author | Nitin Gote <nitin.r.gote@intel.com> | 2025-04-16 16:06:40 +0530 |
|---|---|---|
| committer | Rodrigo Vivi <rodrigo.vivi@intel.com> | 2025-04-29 16:49:20 -0400 |
| commit | ce7743bc1b93cd81b5234b8bb9587607af3f6c2a (patch) | |
| tree | 4452969eceb5d0ce83e77623254d627eeb3a078b | |
| parent | 795dbde92fe5c6996a02a5b579481de73035e7bf (diff) | |
drm/i915/gt: Add delay to let engine resumes properly
Sometimes engine reset fails because the engine resumes from an
incorrect RING_HEAD. Engine head failed to set to zero even after
writing into it. This is a timing issue and we experimented
different values and found out that 20ms delay works best based
on testing.
So, add a 20ms delay to let engine resumes from correct RING_HEAD.
Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/13968
Signed-off-by: Nitin Gote <nitin.r.gote@intel.com>
Reviewed-by: Sebastian Brzezinka <sebastian.brzezinka@intel.com>
Reviewed-by: Krzysztof Karas <krzysztof.karas@intel.com>
Link: https://lore.kernel.org/r/20250416103640.212269-1-nitin.r.gote@intel.com
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
| -rw-r--r-- | drivers/gpu/drm/i915/gt/intel_ring_submission.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/gpu/drm/i915/gt/intel_ring_submission.c b/drivers/gpu/drm/i915/gt/intel_ring_submission.c index 458e29d89978..a93a65c536ec 100644 --- a/drivers/gpu/drm/i915/gt/intel_ring_submission.c +++ b/drivers/gpu/drm/i915/gt/intel_ring_submission.c @@ -365,7 +365,13 @@ static void reset_prepare(struct intel_engine_cs *engine) ENGINE_READ_FW(engine, RING_HEAD), ENGINE_READ_FW(engine, RING_TAIL), ENGINE_READ_FW(engine, RING_START)); - if (!stop_ring(engine)) { + /* + * Sometimes engine head failed to set to zero even after writing into it. + * Use wait_for_atomic() with 20ms delay to let engine resumes from + * correct RING_HEAD. Experimented different values and determined + * that 20ms works best based on testing. + */ + if (wait_for_atomic((!stop_ring(engine) == 0), 20)) { drm_err(&engine->i915->drm, "failed to set %s head to zero " "ctl %08x head %08x tail %08x start %08x\n", |