Chris Wilson <ch...@chris-wilson.co.uk> writes: > After a GPU reset, we need to drain all the CS events so that we have an > accurate picture of the execlists state at the time of the reset. Be > paranoid and force a read of the CSB write pointer from memory. > > Signed-off-by: Chris Wilson <ch...@chris-wilson.co.uk> > Cc: Mika Kuoppala <mika.kuopp...@linux.intel.com> > --- > drivers/gpu/drm/i915/gt/intel_lrc.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c > b/drivers/gpu/drm/i915/gt/intel_lrc.c > index 3d83c7e0d9de..61a38a4ccbca 100644 > --- a/drivers/gpu/drm/i915/gt/intel_lrc.c > +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c > @@ -2836,6 +2836,10 @@ static void __execlists_reset(struct intel_engine_cs > *engine, bool stalled) > struct i915_request *rq; > u32 *regs; > > + mb(); /* paranoia: read the CSB pointers from after the reset */ > + clflush(execlists->csb_write); > + mb(); > +
We know there is always a cost. We do invalidate the csb on each pass on process_csb. Add csb_write in to invalidate_csb entries along with mbs. Rename it to invalidate_csb and use it always? By doing so, we could prolly throw out the rmb() at the start of the process_csb as we would have invalidated the write pointer along with the entries we read, on previous pass. -Mika > process_csb(engine); /* drain preemption events */ > > /* Following the reset, we need to reload the CSB read/write pointers */ > -- > 2.23.0 _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx
