From 19d0a5727123509f0fd8b84551d4715e86937df9 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Mon, 27 Feb 2017 20:58:49 +0000 Subject: [PATCH] drm/i915: Defer enabling hangcheck to the first fake breadcrumb interrupt By deferring hangcheck to the fake breadcrumb interrupt, we can simply the enabling procedure slightly - as by enabling the fake, we then enable the hangcheck. By always enabling the hangcheck from each fake interrupt (it will be a no-op for an already queued hangcheck), it will make restoring the breadcrumbs after a reset simpler in the next patch. Signed-off-by: Chris Wilson Cc: Tvrtko Ursulin Cc: Mika Kuoppala Reviewed-by: Tvrtko Ursulin Link: http://patchwork.freedesktop.org/patch/msgid/20170227205850.2828-3-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/intel_breadcrumbs.c | 36 ++++++++++++------------ 1 file changed, 18 insertions(+), 18 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_breadcrumbs.c b/drivers/gpu/drm/i915/intel_breadcrumbs.c index e7f4a4c923a2..3855c8c39b35 100644 --- a/drivers/gpu/drm/i915/intel_breadcrumbs.c +++ b/drivers/gpu/drm/i915/intel_breadcrumbs.c @@ -75,17 +75,6 @@ static void intel_breadcrumbs_hangcheck(unsigned long data) DRM_DEBUG("Hangcheck timer elapsed... %s idle\n", engine->name); set_bit(engine->id, &engine->i915->gpu_error.missed_irq_rings); mod_timer(&engine->breadcrumbs.fake_irq, jiffies + 1); - - /* Ensure that even if the GPU hangs, we get woken up. - * - * However, note that if no one is waiting, we never notice - * a gpu hang. Eventually, we will have to wait for a resource - * held by the GPU and so trigger a hangcheck. In the most - * pathological case, this will be upon memory starvation! To - * prevent this, we also queue the hangcheck from the retire - * worker. - */ - i915_queue_hangcheck(engine->i915); } static void intel_breadcrumbs_fake_irq(unsigned long data) @@ -99,8 +88,21 @@ static void intel_breadcrumbs_fake_irq(unsigned long data) * every jiffie in order to kick the oldest waiter to do the * coherent seqno check. */ - if (intel_engine_wakeup(engine)) - mod_timer(&engine->breadcrumbs.fake_irq, jiffies + 1); + if (!intel_engine_wakeup(engine)) + return; + + mod_timer(&engine->breadcrumbs.fake_irq, jiffies + 1); + + /* Ensure that even if the GPU hangs, we get woken up. + * + * However, note that if no one is waiting, we never notice + * a gpu hang. Eventually, we will have to wait for a resource + * held by the GPU and so trigger a hangcheck. In the most + * pathological case, this will be upon memory starvation! To + * prevent this, we also queue the hangcheck from the retire + * worker. + */ + i915_queue_hangcheck(engine->i915); } static void irq_enable(struct intel_engine_cs *engine) @@ -179,13 +181,11 @@ static void __intel_breadcrumbs_enable_irq(struct intel_breadcrumbs *b) b->irq_enabled = true; } - if (!b->irq_enabled || use_fake_irq(b)) { + /* Ensure we never sleep indefinitely */ + if (!b->irq_enabled || use_fake_irq(b)) mod_timer(&b->fake_irq, jiffies + 1); - i915_queue_hangcheck(i915); - } else { - /* Ensure we never sleep indefinitely */ + else mod_timer(&b->hangcheck, wait_timeout()); - } } static void __intel_breadcrumbs_disable_irq(struct intel_breadcrumbs *b) -- 2.30.2