Commit 5a6b5458 authored by Aric Cyr's avatar Aric Cyr Committed by Alex Deucher
Browse files

drm/amd/display: LFC not working on 2.0x range monitors (v2) 



[Why]
Nominal pixel clock and EDID information differ in precision so although
monitor reports maximum refresh is 2x minimum, LFC was not being
enabled.

[How]
Use minimum refresh rate as nominal/2 when EDID dictates that min
refresh = max refresh/2.

v2: squash in 64 bit divide fix

Signed-off-by: default avatarAric Cyr <aric.cyr@amd.com>
Reviewed-by: default avatarNicholas Kazlauskas <Nicholas.Kazlauskas@amd.com>
Acked-by: default avatarRodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 5c41c023

drivers/gpu/drm/amd/display/modules/freesync/freesync.c

+19 −15
Original line number Diff line number Diff line
@@ -734,6 +734,7 @@ void mod_freesync_build_vrr_params(struct mod_freesync *mod_freesync, 
{

	struct core_freesync *core_freesync = NULL;

	unsigned long long nominal_field_rate_in_uhz = 0;

	unsigned long long rounded_nominal_in_uhz = 0;

	unsigned int refresh_range = 0;

	unsigned long long min_refresh_in_uhz = 0;

	unsigned long long max_refresh_in_uhz = 0;
@@ -750,17 +751,20 @@ void mod_freesync_build_vrr_params(struct mod_freesync *mod_freesync, 
	min_refresh_in_uhz = in_config->min_refresh_in_uhz;

	max_refresh_in_uhz = in_config->max_refresh_in_uhz;



	// Don't allow min > max

	if (min_refresh_in_uhz > max_refresh_in_uhz)

		min_refresh_in_uhz = max_refresh_in_uhz;



	// Full range may be larger than current video timing, so cap at nominal

	if (max_refresh_in_uhz > nominal_field_rate_in_uhz)

		max_refresh_in_uhz = nominal_field_rate_in_uhz;



	// Full range may be larger than current video timing, so cap at nominal

	if (min_refresh_in_uhz > nominal_field_rate_in_uhz)

		min_refresh_in_uhz = nominal_field_rate_in_uhz;

	if (min_refresh_in_uhz > max_refresh_in_uhz)

		min_refresh_in_uhz = max_refresh_in_uhz;



	// If a monitor reports exactly max refresh of 2x of min, enforce it on nominal

	rounded_nominal_in_uhz =

			div_u64(nominal_field_rate_in_uhz + 50000, 100000) * 100000;

	if (in_config->max_refresh_in_uhz == (2 * in_config->min_refresh_in_uhz) &&

		in_config->max_refresh_in_uhz == rounded_nominal_in_uhz)

		min_refresh_in_uhz = div_u64(nominal_field_rate_in_uhz, 2);



	if (!vrr_settings_require_update(core_freesync,

			in_config, (unsigned int)min_refresh_in_uhz, (unsigned int)max_refresh_in_uhz,
@@ -792,11 +796,6 @@ void mod_freesync_build_vrr_params(struct mod_freesync *mod_freesync, 
		refresh_range = in_out_vrr->max_refresh_in_uhz -

				in_out_vrr->min_refresh_in_uhz;



		in_out_vrr->btr.margin_in_us = in_out_vrr->max_duration_in_us -

				2 * in_out_vrr->min_duration_in_us;

		if (in_out_vrr->btr.margin_in_us > BTR_MAX_MARGIN)

			in_out_vrr->btr.margin_in_us = BTR_MAX_MARGIN;



		in_out_vrr->supported = true;

	}
@@ -804,9 +803,14 @@ void mod_freesync_build_vrr_params(struct mod_freesync *mod_freesync, 


	in_out_vrr->btr.btr_enabled = in_config->btr;



	if (in_out_vrr->max_refresh_in_uhz <

			2 * in_out_vrr->min_refresh_in_uhz)

	if (in_out_vrr->max_refresh_in_uhz < (2 * in_out_vrr->min_refresh_in_uhz))

		in_out_vrr->btr.btr_enabled = false;

	else {

		in_out_vrr->btr.margin_in_us = in_out_vrr->max_duration_in_us -

				2 * in_out_vrr->min_duration_in_us;

		if (in_out_vrr->btr.margin_in_us > BTR_MAX_MARGIN)

			in_out_vrr->btr.margin_in_us = BTR_MAX_MARGIN;

	}



	in_out_vrr->btr.btr_active = false;

	in_out_vrr->btr.inserted_duration_in_us = 0;
@@ -1008,8 +1012,8 @@ unsigned long long mod_freesync_calc_nominal_field_rate( 
	unsigned int total = stream->timing.h_total * stream->timing.v_total;



	/* Calculate nominal field rate for stream, rounded up to nearest integer */

	nominal_field_rate_in_uhz = stream->timing.pix_clk_100hz / 10;

	nominal_field_rate_in_uhz *= 1000ULL * 1000ULL * 1000ULL;

	nominal_field_rate_in_uhz = stream->timing.pix_clk_100hz;

	nominal_field_rate_in_uhz *= 100000000ULL;



	nominal_field_rate_in_uhz =	div_u64(nominal_field_rate_in_uhz, total);

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