Commit 536faa45 authored by Stanislav Lisovskiy's avatar Stanislav Lisovskiy Committed by Maarten Lankhorst
Browse files

drm: Add helper to compare edids. 



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: default avatarStanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Signed-off-by: default avatarMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200630002700.5451-2-kunal1.joshi@intel.com
parent e9d636ab

drivers/gpu/drm/drm_edid.c

+33 −0
Original line number Diff line number Diff line
@@ -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

include/drm/drm_edid.h

+9 −0
Original line number Diff line number Diff line
@@ -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,

					 const struct drm_connector *connector,

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