diff options
Diffstat (limited to 'drivers/gpu/drm/amd/display/dc/link/link_detection.c')
| -rw-r--r-- | drivers/gpu/drm/amd/display/dc/link/link_detection.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/drivers/gpu/drm/amd/display/dc/link/link_detection.c b/drivers/gpu/drm/amd/display/dc/link/link_detection.c index 5d287874c125..d163360a2bf6 100644 --- a/drivers/gpu/drm/amd/display/dc/link/link_detection.c +++ b/drivers/gpu/drm/amd/display/dc/link/link_detection.c @@ -868,6 +868,11 @@ static void verify_link_capability(struct dc_link *link, struct dc_sink *sink, * Evaluates an 8-byte EDID header to check if it's good enough * for the purpose of determining whether a display is connected * without reading the full EDID. + * + * @edid_header: The first 8 bytes of the EDID read from DDC. + * + * Return: true if the header looks valid (>= 6 of 8 bytes match the + * expected 00/FF pattern), false otherwise. */ static bool link_detect_evaluate_edid_header(uint8_t edid_header[8]) { @@ -886,6 +891,11 @@ static bool link_detect_evaluate_edid_header(uint8_t edid_header[8]) * Detect whether a display is connected to DDC without reading full EDID. * Reads only the EDID header (the first 8 bytes of EDID) from DDC and * evaluates whether that matches. + * + * @link: DC link whose DDC/I2C is probed for the EDID header. + * + * Return: true if the EDID header was read and passes validation, + * false otherwise. */ static bool link_detect_ddc_probe(struct dc_link *link) { @@ -910,6 +920,11 @@ static bool link_detect_ddc_probe(struct dc_link *link) * Load detection can be used to detect the presence of an * analog display when we can't read DDC. This causes a visible * visual glitch so it should be used sparingly. + * + * @link: DC link to test using the DAC load-detect path. + * + * Return: true if the VBIOS load-detect call reports OK, false + * otherwise. */ static bool link_detect_dac_load_detect(struct dc_link *link) { @@ -1351,6 +1366,14 @@ static bool detect_link_and_local_sink(struct dc_link *link, /** * link_detect_analog() - Determines if an analog sink is connected. + * + * @link: DC link to evaluate (must support analog signalling). + * @type: Updated with the detected connection type: + * dc_connection_single (analog via DDC), + * dc_connection_dac_load (via load-detect), + * or dc_connection_none. + * + * Return: true if detection completed. */ static bool link_detect_analog(struct dc_link *link, enum dc_connection_type *type) { |