drm/mm: fix dump table BUG

In

commit 9e8944ab564f2e3dde90a518cd32048c58918608
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Thu Nov 15 11:32:17 2012 +0000

    drm: Introduce an iterator over holes in the drm_mm range manager

helpers and iterators for hole handling have been introduced with some
debug BUG_ONs sprinkled over. Unfortunately this broke the mm dumper
which unconditionally tried to compute the size of the very first
hole.

While at it unify the code a bit with the hole dumping in the loop.

v2: Extract a hole dump helper.

Reported-by: Christopher Harvey <charvey@matrox.com>
Cc: Christopher Harvey <charvey@matrox.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: stable@vger.kernel.org
Acked-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 18 insertions, 16 deletions

diff --git a/drivers/gpu/drm/drm_mm.c b/drivers/gpu/drm/drm_mm.c
index db1e2d6f90d7..07cf99cc8862 100644
--- a/drivers/gpu/drm/drm_mm.c
+++ b/drivers/gpu/drm/drm_mm.c
@@ -755,33 +755,35 @@ void drm_mm_debug_table(struct drm_mm *mm, const char *prefix)
 EXPORT_SYMBOL(drm_mm_debug_table);
 
 #if defined(CONFIG_DEBUG_FS)
-int drm_mm_dump_table(struct seq_file *m, struct drm_mm *mm)
+static unsigned long drm_mm_dump_hole(struct seq_file *m, struct drm_mm_node *entry)
 {
-        struct drm_mm_node *entry;
-        unsigned long total_used = 0, total_free = 0, total = 0;
         unsigned long hole_start, hole_end, hole_size;
 
-        hole_start = drm_mm_hole_node_start(&mm->head_node);
-        hole_end = drm_mm_hole_node_end(&mm->head_node);
-        hole_size = hole_end - hole_start;
-        if (hole_size)
+        if (entry->hole_follows) {
+                hole_start = drm_mm_hole_node_start(entry);
+                hole_end = drm_mm_hole_node_end(entry);
+                hole_size = hole_end - hole_start;
                 seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: free\n",
                                 hole_start, hole_end, hole_size);
-        total_free += hole_size;
+                return hole_size;
+        }
+
+        return 0;
+}
+
+int drm_mm_dump_table(struct seq_file *m, struct drm_mm *mm)
+{
+        struct drm_mm_node *entry;
+        unsigned long total_used = 0, total_free = 0, total = 0;
+
+        total_free += drm_mm_dump_hole(m, &mm->head_node);
 
         drm_mm_for_each_node(entry, mm) {
                 seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: used\n",
                                 entry->start, entry->start + entry->size,
                                 entry->size);
                 total_used += entry->size;
-                if (entry->hole_follows) {
-                        hole_start = drm_mm_hole_node_start(entry);
-                        hole_end = drm_mm_hole_node_end(entry);
-                        hole_size = hole_end - hole_start;
-                        seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: free\n",
-                                        hole_start, hole_end, hole_size);
-                        total_free += hole_size;
-                }
+                total_free += drm_mm_dump_hole(m, entry);
         }
         total = total_free + total_used;