From: Stanislav Lisovskiy stanislav.lisovskiy@intel.com
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@intel.com --- 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,