Commit 3fe5739d authored by Angus Wang's avatar Angus Wang Committed by Alex Deucher
Browse files

drm/amd/display: Add flip interval workaround 



[WHY]
Some games experience low FPS issues when FreeSync is on and VSync is
toggled to half refresh rate.

[HOW]
First create a function to determine workaround conditions, which is
when we detect 2 or more VSync interrupts between flips and a very short
VSync to flip interval. We do the workaround during VSync interrupts and
set the v_total_max and min to nominal. We also cleanup after we exit
the game.

Tested-by: default avatarDaniel Wheeler <daniel.wheeler@amd.com>
Reviewed-by: default avatarAnthony Koo <Anthony.Koo@amd.com>
Reviewed-by: default avatarAric Cyr <Aric.Cyr@amd.com>
Acked-by: default avatarTom Chung <chiahsuan.chung@amd.com>
Signed-off-by: default avatarAngus Wang <Angus.Wang@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 35b2186b

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

+73 −1
Original line number Diff line number Diff line
@@ -29,6 +29,7 @@ 
#include "dc.h"

#include "mod_freesync.h"

#include "core_types.h"

#include "dm_services.h"



#define MOD_FREESYNC_MAX_CONCURRENT_STREAMS  32
@@ -46,6 +47,10 @@ 
/* Number of consecutive frames to check before entering/exiting fixed refresh */

#define FIXED_REFRESH_ENTER_FRAME_COUNT 5

#define FIXED_REFRESH_EXIT_FRAME_COUNT 10

/* Flip interval workaround constants */

#define VSYNCS_BETWEEN_FLIP_THRESHOLD 2

#define FREESYNC_CONSEC_FLIP_AFTER_VSYNC 5

#define FREESYNC_VSYNC_TO_FLIP_DELTA_IN_US 500



struct core_freesync {

	struct mod_freesync public;
@@ -466,6 +471,41 @@ static void apply_fixed_refresh(struct core_freesync *core_freesync, 
	}

}



static void determine_flip_interval_workaround_req(struct mod_vrr_params *in_vrr,

		unsigned int curr_time_stamp_in_us)

{

	in_vrr->flip_interval.vsync_to_flip_in_us = curr_time_stamp_in_us -

			in_vrr->flip_interval.v_update_timestamp_in_us;



	/* Determine conditions for stopping workaround */

	if (in_vrr->flip_interval.flip_interval_workaround_active &&

			in_vrr->flip_interval.vsyncs_between_flip < VSYNCS_BETWEEN_FLIP_THRESHOLD &&

			in_vrr->flip_interval.vsync_to_flip_in_us > FREESYNC_VSYNC_TO_FLIP_DELTA_IN_US) {

		in_vrr->flip_interval.flip_interval_detect_counter = 0;

		in_vrr->flip_interval.program_flip_interval_workaround = true;

		in_vrr->flip_interval.flip_interval_workaround_active = false;

	} else {

		/* Determine conditions for starting workaround */

		if (in_vrr->flip_interval.vsyncs_between_flip >= VSYNCS_BETWEEN_FLIP_THRESHOLD &&

				in_vrr->flip_interval.vsync_to_flip_in_us < FREESYNC_VSYNC_TO_FLIP_DELTA_IN_US) {

			/* Increase flip interval counter we have 2 vsyncs between flips and

			 * vsync to flip interval is less than 500us

			 */

			in_vrr->flip_interval.flip_interval_detect_counter++;

			if (in_vrr->flip_interval.flip_interval_detect_counter > FREESYNC_CONSEC_FLIP_AFTER_VSYNC) {

				/* Start workaround if we detect 5 consecutive instances of the above case */

				in_vrr->flip_interval.program_flip_interval_workaround = true;

				in_vrr->flip_interval.flip_interval_workaround_active = true;

			}

		} else {

			/* Reset the flip interval counter if we condition is no longer met */

			in_vrr->flip_interval.flip_interval_detect_counter = 0;

		}

	}



	in_vrr->flip_interval.vsyncs_between_flip = 0;

}



static bool vrr_settings_require_update(struct core_freesync *core_freesync,

		struct mod_freesync_config *in_config,

		unsigned int min_refresh_in_uhz,
@@ -1179,6 +1219,9 @@ void mod_freesync_handle_preflip(struct mod_freesync *mod_freesync, 
				in_out_vrr);

		}



		determine_flip_interval_workaround_req(in_out_vrr,

				curr_time_stamp_in_us);



	}

}
@@ -1187,6 +1230,7 @@ void mod_freesync_handle_v_update(struct mod_freesync *mod_freesync, 
		struct mod_vrr_params *in_out_vrr)

{

	struct core_freesync *core_freesync = NULL;

	unsigned int cur_timestamp_in_us;



	if ((mod_freesync == NULL) || (stream == NULL) || (in_out_vrr == NULL))

		return;
@@ -1196,6 +1240,34 @@ void mod_freesync_handle_v_update(struct mod_freesync *mod_freesync, 
	if (in_out_vrr->supported == false)

		return;



	cur_timestamp_in_us = dm_get_timestamp(core_freesync->dc->ctx)/10;



	in_out_vrr->flip_interval.vsyncs_between_flip++;

	in_out_vrr->flip_interval.v_update_timestamp_in_us = cur_timestamp_in_us;



	if (in_out_vrr->state == VRR_STATE_ACTIVE_VARIABLE &&

			(in_out_vrr->flip_interval.flip_interval_workaround_active ||

			(!in_out_vrr->flip_interval.flip_interval_workaround_active &&

			in_out_vrr->flip_interval.program_flip_interval_workaround))) {

		// set freesync vmin vmax to nominal for workaround

		in_out_vrr->adjust.v_total_min =

			mod_freesync_calc_v_total_from_refresh(

			stream, in_out_vrr->max_refresh_in_uhz);

		in_out_vrr->adjust.v_total_max =

				in_out_vrr->adjust.v_total_min;

		in_out_vrr->flip_interval.program_flip_interval_workaround = false;

		in_out_vrr->flip_interval.do_flip_interval_workaround_cleanup = true;

		return;

	}



	if (in_out_vrr->state != VRR_STATE_ACTIVE_VARIABLE &&

			in_out_vrr->flip_interval.do_flip_interval_workaround_cleanup) {

		in_out_vrr->flip_interval.do_flip_interval_workaround_cleanup = false;

		in_out_vrr->flip_interval.flip_interval_detect_counter = 0;

		in_out_vrr->flip_interval.vsyncs_between_flip = 0;

		in_out_vrr->flip_interval.vsync_to_flip_in_us = 0;

	}



	/* Below the Range Logic */



	/* Only execute if in fullscreen mode */

drivers/gpu/drm/amd/display/modules/inc/mod_freesync.h

+12 −0
Original line number Diff line number Diff line
@@ -105,6 +105,16 @@ struct mod_vrr_params_fixed_refresh { 
	uint32_t frame_counter;

};



struct mod_vrr_params_flip_interval {

	bool flip_interval_workaround_active;

	bool program_flip_interval_workaround;

	bool do_flip_interval_workaround_cleanup;

	uint32_t flip_interval_detect_counter;

	uint32_t vsyncs_between_flip;

	uint32_t vsync_to_flip_in_us;

	uint32_t v_update_timestamp_in_us;

};



struct mod_vrr_params {

	bool supported;

	bool send_info_frame;
@@ -121,6 +131,8 @@ struct mod_vrr_params { 
	struct mod_vrr_params_fixed_refresh fixed;



	struct mod_vrr_params_btr btr;



	struct mod_vrr_params_flip_interval flip_interval;

};



struct mod_freesync *mod_freesync_create(struct dc *dc);