drm/i915: Fix possible null pointer dereference after drm_dbg_printer conversion

Request can be NULL if no guilty request was identified so simply use
engine->i915 instead.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Fixes: d50892a9554c ("drm/i915: switch from drm_debug_printer() to device specific drm_dbg_printer()")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Luca Coelho <luciano.coelho@intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://lore.kernel.org/r/20240219131423.1854991-1-tvrtko.ursulin@linux.intel.com
Signed-off-by: Maxime Ripard <mripard@kernel.org>

diff --git a/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c b/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c
index 0f6406f0cca0294ac38ca3a3fe40371c8ccfb555..1247cc418a1c30642aaf531a630362479e30bbed 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c
+++ b/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c
@@ -96,8 +96,8 @@ static void heartbeat_commit(struct i915_request *rq,
 static void show_heartbeat(const struct i915_request *rq,
                           struct intel_engine_cs *engine)
 {
-       struct drm_printer p = drm_dbg_printer(&rq->i915->drm, DRM_UT_DRIVER,
-                                              "heartbeat");
+       struct drm_printer p =
+               drm_dbg_printer(&engine->i915->drm, DRM_UT_DRIVER, "heartbeat");
 
        if (!rq) {
                intel_engine_dump(engine, &p,