From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Fri, 15 Jun 2018 10:31:36 +0100
Subject: drm/i915: Be irqsafe inside reset
Git-commit: 042ed2dbe5b294e6c225e12d380062ee6adb3ac0
Patch-mainline: v4.19-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

As we want to be able to call i915_reset_engine and co from a softirq or
timer context, we need to be irqsafe at all times. So we have to forgo
the simple spin_lock_irq for the full spin_lock_irqsave.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180615093137.14270-1-chris@chris-wilson.co.uk

Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/i915/i915_gem.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3179,15 +3179,17 @@ i915_gem_reset_request(struct intel_engi
 		 */
 		request = i915_gem_find_active_request(engine);
 		if (request) {
+			unsigned long flags;
+
 			i915_gem_context_mark_innocent(request->gem_context);
 			dma_fence_set_error(&request->fence, -EAGAIN);
 
 			/* Rewind the engine to replay the incomplete rq */
-			spin_lock_irq(&engine->timeline.lock);
+			spin_lock_irqsave(&engine->timeline.lock, flags);
 			request = list_prev_entry(request, link);
 			if (&request->link == &engine->timeline.requests)
 				request = NULL;
-			spin_unlock_irq(&engine->timeline.lock);
+			spin_unlock_irqrestore(&engine->timeline.lock, flags);
 		}
 	}