Chris Wilson <[email protected]> writes: > Upon gt resume, we first poison then sanitize the engine. However, our > testing shows that gen9 will very rarely retain the poisoned value from > the HWSP mappings of the execlists status registers. This suggests that > it is reading back from the HWSP, so rejig the register reset. > > Signed-off-by: Chris Wilson <[email protected]>
Acked-by: Mika Kuoppala <[email protected]> > --- > drivers/gpu/drm/i915/gt/intel_lrc.c | 19 +++++++++++++------ > 1 file changed, 13 insertions(+), 6 deletions(-) > > diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c > b/drivers/gpu/drm/i915/gt/intel_lrc.c > index 3d0e0894c015..a7d644a21f14 100644 > --- a/drivers/gpu/drm/i915/gt/intel_lrc.c > +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c > @@ -3924,6 +3924,14 @@ static void reset_csb_pointers(struct intel_engine_cs > *engine) > > ring_set_paused(engine, 0); > > + /* > + * Sometimes Icelake forgets to reset its pointers on a GPU reset. > + * Bludgeon them with a mmio update to be sure. > + */ > + ENGINE_WRITE(engine, RING_CONTEXT_STATUS_PTR, > + reset_value << 8 | reset_value); > + ENGINE_POSTING_READ(engine, RING_CONTEXT_STATUS_PTR); > + > /* > * After a reset, the HW starts writing into CSB entry [0]. We > * therefore have to set our HEAD pointer back one entry so that > @@ -3937,16 +3945,15 @@ static void reset_csb_pointers(struct intel_engine_cs > *engine) > WRITE_ONCE(*execlists->csb_write, reset_value); > wmb(); /* Make sure this is visible to HW (paranoia?) */ > > - /* > - * Sometimes Icelake forgets to reset its pointers on a GPU reset. > - * Bludgeon them with a mmio update to be sure. > - */ > + invalidate_csb_entries(&execlists->csb_status[0], > + &execlists->csb_status[reset_value]); > + > + /* Once more for luck and our trusty paranoia */ > ENGINE_WRITE(engine, RING_CONTEXT_STATUS_PTR, > reset_value << 8 | reset_value); > ENGINE_POSTING_READ(engine, RING_CONTEXT_STATUS_PTR); > > - invalidate_csb_entries(&execlists->csb_status[0], > - &execlists->csb_status[reset_value]); > + GEM_BUG_ON(READ_ONCE(*execlists->csb_write) != reset_value); > } > > static void execlists_sanitize(struct intel_engine_cs *engine) > -- > 2.20.1 _______________________________________________ Intel-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/intel-gfx
