Commit 3f2f6533 authored by Lespiau, Damien's avatar Lespiau, Damien Committed by Dave Airlie
Browse files

drm: Add support for alternate clocks of 4k modes 



v2: Fix hmdi typo (Simon Farnsworth, Ville Syrjälä)

Suggested-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: default avatarDamien Lespiau <damien.lespiau@intel.com>
Reviewed-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: default avatarSimon Farnsworth <simon.farnsworth@onelan.co.uk>
Reviewed-by: default avatarThierry Reding <treding@nvidia.com>
Signed-off-by: default avatarDave Airlie <airlied@gmail.com>
parent 7ebe1963

drivers/gpu/drm/drm_edid.c

+62 −6
Original line number Diff line number Diff line
@@ -2409,6 +2409,54 @@ u8 drm_match_cea_mode(const struct drm_display_mode *to_match) 
}

EXPORT_SYMBOL(drm_match_cea_mode);



/*

 * Calculate the alternate clock for HDMI modes (those from the HDMI vendor

 * specific block).

 *

 * It's almost like cea_mode_alternate_clock(), we just need to add an

 * exception for the VIC 4 mode (4096x2160@24Hz): no alternate clock for this

 * one.

 */

static unsigned int

hdmi_mode_alternate_clock(const struct drm_display_mode *hdmi_mode)

{

	if (hdmi_mode->vdisplay == 4096 && hdmi_mode->hdisplay == 2160)

		return hdmi_mode->clock;



	return cea_mode_alternate_clock(hdmi_mode);

}



/*

 * drm_match_hdmi_mode - look for a HDMI mode matching given mode

 * @to_match: display mode

 *

 * An HDMI mode is one defined in the HDMI vendor specific block.

 *

 * Returns the HDMI Video ID (VIC) of the mode or 0 if it isn't one.

 */

static u8 drm_match_hdmi_mode(const struct drm_display_mode *to_match)

{

	u8 mode;



	if (!to_match->clock)

		return 0;



	for (mode = 0; mode < ARRAY_SIZE(edid_4k_modes); mode++) {

		const struct drm_display_mode *hdmi_mode = &edid_4k_modes[mode];

		unsigned int clock1, clock2;



		/* Make sure to also match alternate clocks */

		clock1 = hdmi_mode->clock;

		clock2 = hdmi_mode_alternate_clock(hdmi_mode);



		if ((KHZ2PICOS(to_match->clock) == KHZ2PICOS(clock1) ||

		     KHZ2PICOS(to_match->clock) == KHZ2PICOS(clock2)) &&

		    drm_mode_equal_no_clocks(to_match, hdmi_mode))

			return mode + 1;

	}

	return 0;

}



static int

add_alternate_cea_modes(struct drm_connector *connector, struct edid *edid)

{
@@ -2426,18 +2474,26 @@ add_alternate_cea_modes(struct drm_connector *connector, struct edid *edid) 
	 * with the alternate clock for certain CEA modes.

	 */

	list_for_each_entry(mode, &connector->probed_modes, head) {

		const struct drm_display_mode *cea_mode;

		const struct drm_display_mode *cea_mode = NULL;

		struct drm_display_mode *newmode;

		u8 cea_mode_idx = drm_match_cea_mode(mode) - 1;

		u8 mode_idx = drm_match_cea_mode(mode) - 1;

		unsigned int clock1, clock2;



		if (cea_mode_idx >= ARRAY_SIZE(edid_cea_modes))

			continue;

		if (mode_idx < ARRAY_SIZE(edid_cea_modes)) {

			cea_mode = &edid_cea_modes[mode_idx];

			clock2 = cea_mode_alternate_clock(cea_mode);

		} else {

			mode_idx = drm_match_hdmi_mode(mode) - 1;

			if (mode_idx < ARRAY_SIZE(edid_4k_modes)) {

				cea_mode = &edid_4k_modes[mode_idx];

				clock2 = hdmi_mode_alternate_clock(cea_mode);

			}

		}



		cea_mode = &edid_cea_modes[cea_mode_idx];

		if (!cea_mode)

			continue;



		clock1 = cea_mode->clock;

		clock2 = cea_mode_alternate_clock(cea_mode);



		if (clock1 == clock2)

			continue;