From 86aa7e760a6709789a21bdf186bd0c3635da6b9a Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Mon, 23 Jan 2017 11:31:32 +0000
Subject: [PATCH] drm/i915: Assert that the context-switch completion matches
our context
When execlists signals the context completion, it also provides the
context id for the status event. Assert that id matches the one we expect.
v2: The upper dword of the context status is a duplicate of the upper
dword from elsp submission (i.e. includes the group id as well as the
context id). Include this check as well.
v3: Only check against lrc_desc (as this contains the hw_id check)
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170123113132.18665-2-chris@chris-wilson.co.uk
---
drivers/gpu/drm/i915/intel_lrc.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 432ee495dec22..eceffe25c0221 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -595,6 +595,11 @@ static void intel_lrc_irq_handler(unsigned long data)
if (!(status & GEN8_CTX_STATUS_COMPLETED_MASK))
continue;
+ /* Check the context/desc id for this event matches */
+ GEM_BUG_ON(readl(buf + 2 * idx + 1) !=
+ upper_32_bits(intel_lr_context_descriptor(port[0].request->ctx,
+ engine)));
+
GEM_BUG_ON(port[0].count == 0);
if (--port[0].count == 0) {
GEM_BUG_ON(status & GEN8_CTX_STATUS_PREEMPTED);
--
2.30.2