drm: Mark constant arrays of drm_display_mode const

... and fixup some methods to accept the constant argument.

Now that constant module arrays are loaded into read-only memory, using
const appropriately has some benefits beyond warning the programmer
about likely mistakes.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 10 insertions, 9 deletions

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index a245d17165ae..af60d9be9632 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -449,12 +449,11 @@ static void edid_fixup_preferred(struct drm_connector *connector,
 struct drm_display_mode *drm_mode_find_dmt(struct drm_device *dev,
                                            int hsize, int vsize, int fresh)
 {
+        struct drm_display_mode *mode = NULL;
         int i;
-        struct drm_display_mode *ptr, *mode;
 
-        mode = NULL;
         for (i = 0; i < drm_num_dmt_modes; i++) {
-                ptr = &drm_dmt_modes[i];
+                const struct drm_display_mode *ptr = &drm_dmt_modes[i];
                 if (hsize == ptr->hdisplay &&
                         vsize == ptr->vdisplay &&
                         fresh == drm_mode_vrefresh(ptr)) {
@@ -885,7 +884,7 @@ static struct drm_display_mode *drm_mode_detailed(struct drm_device *dev,
 }
 
 static bool
-mode_is_rb(struct drm_display_mode *mode)
+mode_is_rb(const struct drm_display_mode *mode)
 {
         return (mode->htotal - mode->hdisplay == 160) &&
                (mode->hsync_end - mode->hdisplay == 80) &&
@@ -894,7 +893,8 @@ mode_is_rb(struct drm_display_mode *mode)
 }
 
 static bool
-mode_in_hsync_range(struct drm_display_mode *mode, struct edid *edid, u8 *t)
+mode_in_hsync_range(const struct drm_display_mode *mode,
+                    struct edid *edid, u8 *t)
 {
         int hsync, hmin, hmax;
 
@@ -910,7 +910,8 @@ mode_in_hsync_range(struct drm_display_mode *mode, struct edid *edid, u8 *t)
 }
 
 static bool
-mode_in_vsync_range(struct drm_display_mode *mode, struct edid *edid, u8 *t)
+mode_in_vsync_range(const struct drm_display_mode *mode,
+                    struct edid *edid, u8 *t)
 {
         int vsync, vmin, vmax;
 
@@ -941,7 +942,7 @@ range_pixel_clock(struct edid *edid, u8 *t)
 }
 
 static bool
-mode_in_range(struct drm_display_mode *mode, struct edid *edid,
+mode_in_range(const struct drm_display_mode *mode, struct edid *edid,
               struct detailed_timing *timing)
 {
         u32 max_clock;
@@ -1472,7 +1473,7 @@ int drm_add_modes_noedid(struct drm_connector *connector,
                         int hdisplay, int vdisplay)
 {
         int i, count, num_modes = 0;
-        struct drm_display_mode *mode, *ptr;
+        struct drm_display_mode *mode;
         struct drm_device *dev = connector->dev;
 
         count = sizeof(drm_dmt_modes) / sizeof(struct drm_display_mode);
@@ -1482,7 +1483,7 @@ int drm_add_modes_noedid(struct drm_connector *connector,
                 vdisplay = 0;
 
         for (i = 0; i < count; i++) {
-                ptr = &drm_dmt_modes[i];
+                const struct drm_display_mode *ptr = &drm_dmt_modes[i];
                 if (hdisplay && vdisplay) {
                         /*
                          * Only when two are valid, they will be used to check