From: Stanislav Lisovskiy <stanislav.lisovskiy@xxxxxxxxx>
Many drivers would benefit from using
drm helper to compare edid, rather
than bothering with own implementation.
v2: Added documentation for this function.
Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@xxxxxxxxx>
---
drivers/gpu/drm/drm_edid.c | 33 +++++++++++++++++++++++++++++++++
include/drm/drm_edid.h | 9 +++++++++
2 files changed, 42 insertions(+)
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index d8372d63851b..34cabfddcdd3 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -1615,6 +1615,39 @@ static bool drm_edid_is_zero(const u8 *in_edid, int length)
return true;
}
+/**
+ * drm_edid_are_equal - compare two edid blobs.
+ * @edid1: pointer to first blob
+ * @edid2: pointer to second blob
+ * This helper can be used during probing to determine if
+ * edid had changed.
+ */
+bool drm_edid_are_equal(const struct edid *edid1, const struct edid *edid2)
+{
+ int edid1_len, edid2_len;
+ bool edid1_present = edid1 != NULL;
+ bool edid2_present = edid2 != NULL;
+
+ if (edid1_present != edid2_present)
+ return false;
+
+ if (edid1) {
+
+ edid1_len = EDID_LENGTH * (1 + edid1->extensions);
+ edid2_len = EDID_LENGTH * (1 + edid2->extensions);
+
+ if (edid1_len != edid2_len)
+ return false;
+
+ if (memcmp(edid1, edid2, edid1_len))
+ return false;
+ }
+
+ return true;
+}
+EXPORT_SYMBOL(drm_edid_are_equal);
+
+
/**
* drm_edid_block_valid - Sanity check the EDID block (base or extension)
* @raw_edid: pointer to raw EDID block
diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h
index 34b15e3d070c..5c26cc65b786 100644
--- a/include/drm/drm_edid.h
+++ b/include/drm/drm_edid.h
@@ -359,6 +359,15 @@ drm_load_edid_firmware(struct drm_connector *connector)
}
#endif
+/**
+ * drm_edid_are_equal - compare two edid blobs.
+ * @edid1: pointer to first blob
+ * @edid2: pointer to second blob
+ * This helper can be used during probing to determine if
+ * edid had changed.
+ */
+bool drm_edid_are_equal(const struct edid *edid1, const struct edid *edid2);
+
int
drm_hdmi_avi_infoframe_from_display_mode(struct hdmi_avi_infoframe *frame,
struct drm_connector *connector,
--
2.25.1
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