drm/edid: Break out reading block 0 of the EDID

A future change wants to be able to read just block 0 of the EDID, so
break it out of drm_do_get_edid() into a sub-function.

This is intended to be a no-op change--just code movement.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210914132020.v5.2.I62e76a034ac78c994d40a23cd4ec5aeee56fa77c@changeid

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 6325877..520fe13 100644 (file)
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -1905,6 +1905,44 @@ int drm_add_override_edid_modes(struct drm_connector *connector)
 }
 EXPORT_SYMBOL(drm_add_override_edid_modes);
 
+static struct edid *drm_do_get_edid_base_block(
+       int (*get_edid_block)(void *data, u8 *buf, unsigned int block,
+                             size_t len),
+       void *data, bool *edid_corrupt, int *null_edid_counter)
+{
+       int i;
+       void *edid;
+
+       edid = kmalloc(EDID_LENGTH, GFP_KERNEL);
+       if (edid == NULL)
+               return NULL;
+
+       /* base block fetch */
+       for (i = 0; i < 4; i++) {
+               if (get_edid_block(data, edid, 0, EDID_LENGTH))
+                       goto out;
+               if (drm_edid_block_valid(edid, 0, false, edid_corrupt))
+                       break;
+               if (i == 0 && drm_edid_is_zero(edid, EDID_LENGTH)) {
+                       if (null_edid_counter)
+                               (*null_edid_counter)++;
+                       goto carp;
+               }
+       }
+       if (i == 4)
+               goto carp;
+
+       return edid;
+
+carp:
+       kfree(edid);
+       return ERR_PTR(-EINVAL);
+
+out:
+       kfree(edid);
+       return NULL;
+}
+
 /**
  * drm_do_get_edid - get EDID data using a custom EDID block read function
  * @connector: connector we're probing
@@ -1938,25 +1976,16 @@ struct edid *drm_do_get_edid(struct drm_connector *connector,
        if (override)
                return override;
 
-       if ((edid = kmalloc(EDID_LENGTH, GFP_KERNEL)) == NULL)
+       edid = (u8 *)drm_do_get_edid_base_block(get_edid_block, data,
+                                               &connector->edid_corrupt,
+                                               &connector->null_edid_counter);
+       if (IS_ERR_OR_NULL(edid)) {
+               if (IS_ERR(edid))
+                       connector_bad_edid(connector, edid, 1);
                return NULL;
-
-       /* base block fetch */
-       for (i = 0; i < 4; i++) {
-               if (get_edid_block(data, edid, 0, EDID_LENGTH))
-                       goto out;
-               if (drm_edid_block_valid(edid, 0, false,
-                                        &connector->edid_corrupt))
-                       break;
-               if (i == 0 && drm_edid_is_zero(edid, EDID_LENGTH)) {
-                       connector->null_edid_counter++;
-                       goto carp;
-               }
        }
-       if (i == 4)
-               goto carp;
 
-       /* if there's no extensions, we're done */
+       /* if there's no extensions or no connector, we're done */
        valid_extensions = edid[0x7e];
        if (valid_extensions == 0)
                return (struct edid *)edid;
@@ -2010,8 +2039,6 @@ struct edid *drm_do_get_edid(struct drm_connector *connector,
 
        return (struct edid *)edid;
 
-carp:
-       connector_bad_edid(connector, edid, 1);
 out:
        kfree(edid);
        return NULL;