| Message ID | 20180525093206.1919-9-chris@chris-wilson.co.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Chris Wilson <chris@chris-wilson.co.uk> writes: > After a reset, we will ensure that there is at least one request > submitted to HW to ensure that a context is loaded for powersaving. > Let's wait for this submission via a tasklet to complete before we drop > our forcewake, ensuring the system is ready for rc6 before we let it > possible sleep. s/possible/possibly ? > > Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> > --- > drivers/gpu/drm/i915/i915_gem.h | 6 ++++++ > drivers/gpu/drm/i915/intel_lrc.c | 15 ++++++++++++++- > 2 files changed, 20 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/i915/i915_gem.h b/drivers/gpu/drm/i915/i915_gem.h > index 62ee4e385365..261da577829a 100644 > --- a/drivers/gpu/drm/i915/i915_gem.h > +++ b/drivers/gpu/drm/i915/i915_gem.h > @@ -82,4 +82,10 @@ static inline void __tasklet_disable_sync_once(struct tasklet_struct *t) > tasklet_unlock_wait(t); > } > > +static inline void __tasklet_enable_sync_once(struct tasklet_struct *t) > +{ > + if (atomic_dec_return(&t->count) == 0) > + tasklet_kill(t); > +} > + > #endif /* __I915_GEM_H__ */ > diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c > index b3a5cfb7689f..f2fb48b1a7b7 100644 > --- a/drivers/gpu/drm/i915/intel_lrc.c > +++ b/drivers/gpu/drm/i915/intel_lrc.c > @@ -1877,6 +1877,8 @@ execlists_reset_prepare(struct intel_engine_cs *engine) > > GEM_TRACE("%s\n", engine->name); > > + intel_uncore_forcewake_get(engine->i915, FORCEWAKE_ALL); > + > /* > * Prevent request submission to the hardware until we have > * completed the reset in i915_gem_reset_finish(). If a request > @@ -2007,7 +2009,18 @@ static void execlists_reset(struct intel_engine_cs *engine, > > static void execlists_reset_finish(struct intel_engine_cs *engine) > { > - tasklet_enable(&engine->execlists.tasklet); > + /* > + * Flush the tasklet while we still have the forcewake to be sure > + * that it is not allowed to sleep before we restart and reload a > + * context. > + * > + * As before (with execlists_reset_prepare) we rely on the caller > + * serialising mutiple attempts to reset so that we know that we s/mutiple/multiple > + * are the only one manipulating tasklet state. > + */ > + __tasklet_enable_sync_once(&engine->execlists.tasklet); > + > + intel_uncore_forcewake_put(engine->i915, FORCEWAKE_ALL); as discussed in irc, we already hold forcewakes on behalf of prepare_engine() above us. With forcewake_put/get removed, Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com> > > GEM_TRACE("%s\n", engine->name); > } > -- > 2.17.0 > > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
diff --git a/drivers/gpu/drm/i915/i915_gem.h b/drivers/gpu/drm/i915/i915_gem.h index 62ee4e385365..261da577829a 100644 --- a/drivers/gpu/drm/i915/i915_gem.h +++ b/drivers/gpu/drm/i915/i915_gem.h @@ -82,4 +82,10 @@ static inline void __tasklet_disable_sync_once(struct tasklet_struct *t) tasklet_unlock_wait(t); } +static inline void __tasklet_enable_sync_once(struct tasklet_struct *t) +{ + if (atomic_dec_return(&t->count) == 0) + tasklet_kill(t); +} + #endif /* __I915_GEM_H__ */ diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c index b3a5cfb7689f..f2fb48b1a7b7 100644 --- a/drivers/gpu/drm/i915/intel_lrc.c +++ b/drivers/gpu/drm/i915/intel_lrc.c @@ -1877,6 +1877,8 @@ execlists_reset_prepare(struct intel_engine_cs *engine) GEM_TRACE("%s\n", engine->name); + intel_uncore_forcewake_get(engine->i915, FORCEWAKE_ALL); + /* * Prevent request submission to the hardware until we have * completed the reset in i915_gem_reset_finish(). If a request @@ -2007,7 +2009,18 @@ static void execlists_reset(struct intel_engine_cs *engine, static void execlists_reset_finish(struct intel_engine_cs *engine) { - tasklet_enable(&engine->execlists.tasklet); + /* + * Flush the tasklet while we still have the forcewake to be sure + * that it is not allowed to sleep before we restart and reload a + * context. + * + * As before (with execlists_reset_prepare) we rely on the caller + * serialising mutiple attempts to reset so that we know that we + * are the only one manipulating tasklet state. + */ + __tasklet_enable_sync_once(&engine->execlists.tasklet); + + intel_uncore_forcewake_put(engine->i915, FORCEWAKE_ALL); GEM_TRACE("%s\n", engine->name); }
After a reset, we will ensure that there is at least one request submitted to HW to ensure that a context is loaded for powersaving. Let's wait for this submission via a tasklet to complete before we drop our forcewake, ensuring the system is ready for rc6 before we let it possible sleep. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> --- drivers/gpu/drm/i915/i915_gem.h | 6 ++++++ drivers/gpu/drm/i915/intel_lrc.c | 15 ++++++++++++++- 2 files changed, 20 insertions(+), 1 deletion(-)