From 93c97dc17ffc4a0651b5a939d1ef34897513b252 Mon Sep 17 00:00:00 2001 From: Imre Deak Date: Mon, 7 Nov 2016 11:20:03 +0200 Subject: [PATCH] drm/i915: Avoid early GPU idling due to race with new request There is a small race where a new request can be submitted and retired after the idle worker started to run which leads to idling the GPU too early. Fix this by deferring the idling to the pending instance of the worker. This scenario was pointed out by Chris. Cc: Chris Wilson Signed-off-by: Imre Deak Reviewed-by: Chris Wilson Link: http://patchwork.freedesktop.org/patch/msgid/1478510405-11799-2-git-send-email-imre.deak@intel.com --- drivers/gpu/drm/i915/i915_gem.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 490fd302bd1a..82170bcb3bf3 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -2766,6 +2766,13 @@ i915_gem_idle_work_handler(struct work_struct *work) goto out_rearm; } + /* + * New request retired after this work handler started, extend active + * period until next instance of the work. + */ + if (work_pending(work)) + goto out_unlock; + if (dev_priv->gt.active_requests) goto out_unlock; -- 2.11.0