drm/i915: Add a sunset clause to GPU hang logging

If the kernel is old, more than a few releases old, chances are that the
user is using an old kernel for a good reason, despite there being GPU
hangs. After 180days since driver release stop suggesting that they
should send those reports upstream.

[Since Daniel acked this I expect he will pick up the dim patch to
automatically update the DRIVER_TIMESTAMP everytime we tag a new
release.]

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161014134428.29582-1-chris@chris-wilson.co.uk
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

drivers/gpu/drm/i915/i915_drv.h

@@ -71,6 +71,7 @@
 #define DRIVER_NAME		"i915"
 #define DRIVER_DESC		"Intel Graphics"
 #define DRIVER_DATE		"20161010"
+#define DRIVER_TIMESTAMP	1476452087
 
 #undef WARN_ON
 /* Many gcc seem to no see through this and fall over :( */

drivers/gpu/drm/i915/i915_gpu_error.c

@@ -1541,6 +1541,8 @@ static int capture(void *data)
 	return 0;
 }
 
+#define DAY_AS_SECONDS(x) (24 * 60 * 60 * (x))
+
 /**
  * i915_capture_error_state - capture an error record for later analysis
  * @dev: drm device
@@ -1593,7 +1595,8 @@ void i915_capture_error_state(struct drm_i915_private *dev_priv,
 		return;
 	}
 
-	if (!warned) {
+	if (!warned &&
+	    ktime_get_real_seconds() - DRIVER_TIMESTAMP < DAY_AS_SECONDS(180)) {
 		DRM_INFO("GPU hangs can indicate a bug anywhere in the entire gfx stack, including userspace.\n");
 		DRM_INFO("Please file a _new_ bug report on bugs.freedesktop.org against DRI -> DRM/Intel\n");
 		DRM_INFO("drm/i915 developers can then reassign to the right component if it's not a kernel issue.\n");