i915: Don't dereference HWS in /proc debug files when it isn't initialized.

Signed-off-by: Eric Anholt <eric@anholt.net>
Acked-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 12 insertions, 3 deletions

diff --git a/drivers/gpu/drm/i915/i915_gem_proc.c b/drivers/gpu/drm/i915/i915_gem_proc.c
index 15d4160415b0..93de15b4c9a7 100644
--- a/drivers/gpu/drm/i915/i915_gem_proc.c
+++ b/drivers/gpu/drm/i915/i915_gem_proc.c
@@ -192,7 +192,12 @@ static int i915_gem_seqno_info(char *buf, char **start, off_t offset,
 
         *start = &buf[offset];
         *eof = 0;
-        DRM_PROC_PRINT("Current sequence: %d\n", i915_get_gem_seqno(dev));
+        if (dev_priv->hw_status_page != NULL) {
+                DRM_PROC_PRINT("Current sequence: %d\n",
+                               i915_get_gem_seqno(dev));
+        } else {
+                DRM_PROC_PRINT("Current sequence: hws uninitialized\n");
+        }
         DRM_PROC_PRINT("Waiter sequence:  %d\n",
                        dev_priv->mm.waiting_gem_seqno);
         DRM_PROC_PRINT("IRQ sequence:     %d\n", dev_priv->mm.irq_gem_seqno);
@@ -230,8 +235,12 @@ static int i915_interrupt_info(char *buf, char **start, off_t offset,
                        I915_READ(PIPEBSTAT));
         DRM_PROC_PRINT("Interrupts received: %d\n",
                        atomic_read(&dev_priv->irq_received));
-        DRM_PROC_PRINT("Current sequence:    %d\n",
-                       i915_get_gem_seqno(dev));
+        if (dev_priv->hw_status_page != NULL) {
+                DRM_PROC_PRINT("Current sequence:    %d\n",
+                               i915_get_gem_seqno(dev));
+        } else {
+                DRM_PROC_PRINT("Current sequence:    hws uninitialized\n");
+        }
         DRM_PROC_PRINT("Waiter sequence:     %d\n",
                        dev_priv->mm.waiting_gem_seqno);
         DRM_PROC_PRINT("IRQ sequence:        %d\n",