From fe25f3048322f32131a151ebe213f52821322f9c Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Tue, 22 May 2018 11:19:37 +0100 Subject: drm/i915/execlists: Wait for ELSP submission on restart 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 possibly sleep. Signed-off-by: Chris Wilson Link: https://patchwork.freedesktop.org/patch/msgid/20180522101937.7738-1-chris@chris-wilson.co.uk Reviewed-by: Mika Kuoppala --- drivers/gpu/drm/i915/i915_gem.h | 6 ++++++ drivers/gpu/drm/i915/intel_lrc.c | 11 ++++++++++- 2 files changed, 16 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 302af60415a3..4bcd3206991d 100644 --- a/drivers/gpu/drm/i915/intel_lrc.c +++ b/drivers/gpu/drm/i915/intel_lrc.c @@ -2008,7 +2008,16 @@ 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 multiple attempts to reset so that we know that we + * are the only one manipulating tasklet state. + */ + __tasklet_enable_sync_once(&engine->execlists.tasklet); GEM_TRACE("%s\n", engine->name); } -- cgit v1.2.3