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 <ch...@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 + * 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); } -- 2.17.0 _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx