[PATCH 3/4] drm/edid: move displayid validation to it's own function.

[Dave Airlie]

From: Dave Airlie <airl...@redhat.com>

We need to use this for validating modeline additions.

Signed-off-by: Dave Airlie <airlied at redhat.com>
---
 drivers/gpu/drm/drm_edid.c | 44 ++++++++++++++++++++++++++------------------
 1 file changed, 26 insertions(+), 18 deletions(-)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 3cf17a3..73d4218 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -3901,6 +3901,29 @@ static void drm_add_display_info(struct edid *edid,
                info->color_formats |= DRM_COLOR_FORMAT_YCRCB422;
 }

+static int validate_displayid(u8 *displayid, int length, int idx)
+{
+       int i;
+       u8 csum = 0;
+       struct displayid_hdr *base;
+
+       base = (struct displayid_hdr *)&displayid[idx];
+
+       DRM_DEBUG_KMS("base revision 0x%x, length %d, %d %d\n",
+                     base->rev, base->bytes, base->prod_id, base->ext_count);
+
+       if (base->bytes + 5 > length - idx)
+               return -EINVAL;
+       for (i = idx; i <= base->bytes + 5; i++) {
+               csum += displayid[i];
+       }
+       if (csum) {
+               DRM_ERROR("DisplayID checksum invalid, remainder is %d\n", 
csum);
+               return -EINVAL;
+       }
+       return 0;
+}
+
 /**
  * drm_add_edid_modes - add modes from EDID data, if available
  * @connector: connector we're probing
@@ -4212,30 +4235,15 @@ static int drm_parse_display_id(struct drm_connector 
*connector,
 {
        /* if this is an EDID extension the first byte will be 0x70 */
        int idx = 0;
-       struct displayid_hdr *base;
        struct displayid_block *block;
-       u8 csum = 0;
-       int i;
        int ret;

        if (is_edid_extension)
                idx = 1;

-       base = (struct displayid_hdr *)&displayid[idx];
-
-       DRM_DEBUG_KMS("base revision 0x%x, length %d, %d %d\n",
-                     base->rev, base->bytes, base->prod_id, base->ext_count);
-
-       if (base->bytes + 5 > length - idx)
-               return -EINVAL;
-
-       for (i = idx; i <= base->bytes + 5; i++) {
-               csum += displayid[i];
-       }
-       if (csum) {
-               DRM_ERROR("DisplayID checksum invalid, remainder is %d\n", 
csum);
-               return -EINVAL;
-       }
+       ret = validate_displayid(displayid, length, idx);
+       if (ret)
+               return ret;

        idx += sizeof(struct displayid_hdr);
        while (block = (struct displayid_block *)&displayid[idx],
-- 
2.5.5