diff options
| author | Chris Wilson <chris@chris-wilson.co.uk> | 2020-11-02 22:10:57 +0000 |
|---|---|---|
| committer | Rodrigo Vivi <rodrigo.vivi@intel.com> | 2020-11-03 19:22:42 -0500 |
| commit | e67d01d8494640018b08cd767aeb2824a8e11983 (patch) | |
| tree | 1dbb48f036ec19d7c855d97d38e9db3494692e89 /drivers/gpu | |
| parent | 306bb61d6bb3531b0d05429a771ac13a75aa30c8 (diff) | |
| download | linux-stable-e67d01d8494640018b08cd767aeb2824a8e11983.tar.gz linux-stable-e67d01d8494640018b08cd767aeb2824a8e11983.tar.bz2 linux-stable-e67d01d8494640018b08cd767aeb2824a8e11983.zip | |
drm/i915/gt: Flush xcs before tgl breadcrumbs
In a simple test case that writes to scratch and then busy-waits for the
batch to be signaled, we observe that the signal is before the write is
posted. That is bad news.
Splitting the flush + write_dword into two separate flush_dw prevents
the issue from being reproduced, we can presume the post-sync op is not
so post-sync.
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/216
Testcase: igt/gem_exec_fence/parallel
Testcase: igt/i915_selftest/live/gt_timelines
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: stable@vger.kernel.org
Acked-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201102221057.29626-2-chris@chris-wilson.co.uk
(cherry picked from commit 09212e81e5450743e5b06b27c4e344e4c45b630d)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/i915/gt/intel_lrc.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c index d12861cf0753..f82c6dd1de18 100644 --- a/drivers/gpu/drm/i915/gt/intel_lrc.c +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c @@ -4994,7 +4994,9 @@ gen12_emit_fini_breadcrumb_tail(struct i915_request *request, u32 *cs) static u32 *gen12_emit_fini_breadcrumb(struct i915_request *rq, u32 *cs) { - return gen12_emit_fini_breadcrumb_tail(rq, emit_xcs_breadcrumb(rq, cs)); + /* XXX Stalling flush before seqno write; post-sync not */ + cs = emit_xcs_breadcrumb(rq, __gen8_emit_flush_dw(cs, 0, 0, 0)); + return gen12_emit_fini_breadcrumb_tail(rq, cs); } static u32 * |