kernel/drivers/gpu/drm/amd/display/modules/freesync/freesync.c
2024-07-22 17:22:30 +08:00

1350 lines
41 KiB
C

/*
* Copyright 2016 Advanced Micro Devices, Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*
* Authors: AMD
*
*/
#include <linux/slab.h>
#include "dm_services.h"
#include "dc.h"
#include "mod_freesync.h"
#include "core_types.h"
#define MOD_FREESYNC_MAX_CONCURRENT_STREAMS 32
#define MIN_REFRESH_RANGE 10
/* Refresh rate ramp at a fixed rate of 65 Hz/second */
#define STATIC_SCREEN_RAMP_DELTA_REFRESH_RATE_PER_FRAME ((1000 / 60) * 65)
/* Number of elements in the render times cache array */
#define RENDER_TIMES_MAX_COUNT 10
/* Threshold to exit/exit BTR (to avoid frequent enter-exits at the lower limit) */
#define BTR_MAX_MARGIN 2500
/* Threshold to change BTR multiplier (to avoid frequent changes) */
#define BTR_DRIFT_MARGIN 2000
/* Threshold to exit fixed refresh rate */
#define FIXED_REFRESH_EXIT_MARGIN_IN_HZ 1
/* 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
struct core_freesync {
struct mod_freesync public;
struct dc *dc;
};
#define MOD_FREESYNC_TO_CORE(mod_freesync)\
container_of(mod_freesync, struct core_freesync, public)
struct mod_freesync *mod_freesync_create(struct dc *dc)
{
struct core_freesync *core_freesync =
kzalloc(sizeof(struct core_freesync), GFP_KERNEL);
if (core_freesync == NULL)
goto fail_alloc_context;
if (dc == NULL)
goto fail_construct;
core_freesync->dc = dc;
return &core_freesync->public;
fail_construct:
kfree(core_freesync);
fail_alloc_context:
return NULL;
}
void mod_freesync_destroy(struct mod_freesync *mod_freesync)
{
struct core_freesync *core_freesync = NULL;
if (mod_freesync == NULL)
return;
core_freesync = MOD_FREESYNC_TO_CORE(mod_freesync);
kfree(core_freesync);
}
#if 0 /* Unused currently */
static unsigned int calc_refresh_in_uhz_from_duration(
unsigned int duration_in_ns)
{
unsigned int refresh_in_uhz =
((unsigned int)(div64_u64((1000000000ULL * 1000000),
duration_in_ns)));
return refresh_in_uhz;
}
#endif
static unsigned int calc_duration_in_us_from_refresh_in_uhz(
unsigned int refresh_in_uhz)
{
unsigned int duration_in_us =
((unsigned int)(div64_u64((1000000000ULL * 1000),
refresh_in_uhz)));
return duration_in_us;
}
static unsigned int calc_duration_in_us_from_v_total(
const struct dc_stream_state *stream,
const struct mod_vrr_params *in_vrr,
unsigned int v_total)
{
unsigned int duration_in_us =
(unsigned int)(div64_u64(((unsigned long long)(v_total)
* 10000) * stream->timing.h_total,
stream->timing.pix_clk_100hz));
return duration_in_us;
}
unsigned int mod_freesync_calc_v_total_from_refresh(
const struct dc_stream_state *stream,
unsigned int refresh_in_uhz)
{
unsigned int v_total;
unsigned int frame_duration_in_ns;
frame_duration_in_ns =
((unsigned int)(div64_u64((1000000000ULL * 1000000),
refresh_in_uhz)));
v_total = div64_u64(div64_u64(((unsigned long long)(
frame_duration_in_ns) * (stream->timing.pix_clk_100hz / 10)),
stream->timing.h_total), 1000000);
/* v_total cannot be less than nominal */
if (v_total < stream->timing.v_total) {
ASSERT(v_total < stream->timing.v_total);
v_total = stream->timing.v_total;
}
return v_total;
}
static unsigned int calc_v_total_from_duration(
const struct dc_stream_state *stream,
const struct mod_vrr_params *vrr,
unsigned int duration_in_us)
{
unsigned int v_total = 0;
if (duration_in_us < vrr->min_duration_in_us)
duration_in_us = vrr->min_duration_in_us;
if (duration_in_us > vrr->max_duration_in_us)
duration_in_us = vrr->max_duration_in_us;
v_total = div64_u64(div64_u64(((unsigned long long)(
duration_in_us) * (stream->timing.pix_clk_100hz / 10)),
stream->timing.h_total), 1000);
/* v_total cannot be less than nominal */
if (v_total < stream->timing.v_total) {
ASSERT(v_total < stream->timing.v_total);
v_total = stream->timing.v_total;
}
return v_total;
}
static void update_v_total_for_static_ramp(
struct core_freesync *core_freesync,
const struct dc_stream_state *stream,
struct mod_vrr_params *in_out_vrr)
{
unsigned int v_total = 0;
unsigned int current_duration_in_us =
calc_duration_in_us_from_v_total(
stream, in_out_vrr,
in_out_vrr->adjust.v_total_max);
unsigned int target_duration_in_us =
calc_duration_in_us_from_refresh_in_uhz(
in_out_vrr->fixed.target_refresh_in_uhz);
bool ramp_direction_is_up = (current_duration_in_us >
target_duration_in_us) ? true : false;
/* Calculate ratio between new and current frame duration with 3 digit */
unsigned int frame_duration_ratio = div64_u64(1000000,
(1000 + div64_u64(((unsigned long long)(
STATIC_SCREEN_RAMP_DELTA_REFRESH_RATE_PER_FRAME) *
current_duration_in_us),
1000000)));
/* Calculate delta between new and current frame duration in us */
unsigned int frame_duration_delta = div64_u64(((unsigned long long)(
current_duration_in_us) *
(1000 - frame_duration_ratio)), 1000);
/* Adjust frame duration delta based on ratio between current and
* standard frame duration (frame duration at 60 Hz refresh rate).
*/
unsigned int ramp_rate_interpolated = div64_u64(((unsigned long long)(
frame_duration_delta) * current_duration_in_us), 16666);
/* Going to a higher refresh rate (lower frame duration) */
if (ramp_direction_is_up) {
/* Reduce frame duration */
current_duration_in_us -= ramp_rate_interpolated;
/* Adjust for frame duration below min */
if (current_duration_in_us <= target_duration_in_us) {
in_out_vrr->fixed.ramping_active = false;
in_out_vrr->fixed.ramping_done = true;
current_duration_in_us =
calc_duration_in_us_from_refresh_in_uhz(
in_out_vrr->fixed.target_refresh_in_uhz);
}
/* Going to a lower refresh rate (larger frame duration) */
} else {
/* Increase frame duration */
current_duration_in_us += ramp_rate_interpolated;
/* Adjust for frame duration above max */
if (current_duration_in_us >= target_duration_in_us) {
in_out_vrr->fixed.ramping_active = false;
in_out_vrr->fixed.ramping_done = true;
current_duration_in_us =
calc_duration_in_us_from_refresh_in_uhz(
in_out_vrr->fixed.target_refresh_in_uhz);
}
}
v_total = div64_u64(div64_u64(((unsigned long long)(
current_duration_in_us) * (stream->timing.pix_clk_100hz / 10)),
stream->timing.h_total), 1000);
/* v_total cannot be less than nominal */
if (v_total < stream->timing.v_total)
v_total = stream->timing.v_total;
in_out_vrr->adjust.v_total_min = v_total;
in_out_vrr->adjust.v_total_max = v_total;
}
static void apply_below_the_range(struct core_freesync *core_freesync,
const struct dc_stream_state *stream,
unsigned int last_render_time_in_us,
struct mod_vrr_params *in_out_vrr)
{
unsigned int inserted_frame_duration_in_us = 0;
unsigned int mid_point_frames_ceil = 0;
unsigned int mid_point_frames_floor = 0;
unsigned int frame_time_in_us = 0;
unsigned int delta_from_mid_point_in_us_1 = 0xFFFFFFFF;
unsigned int delta_from_mid_point_in_us_2 = 0xFFFFFFFF;
unsigned int frames_to_insert = 0;
unsigned int delta_from_mid_point_delta_in_us;
unsigned int max_render_time_in_us =
in_out_vrr->max_duration_in_us - in_out_vrr->btr.margin_in_us;
/* Program BTR */
if ((last_render_time_in_us + in_out_vrr->btr.margin_in_us / 2) < max_render_time_in_us) {
/* Exit Below the Range */
if (in_out_vrr->btr.btr_active) {
in_out_vrr->btr.frame_counter = 0;
in_out_vrr->btr.btr_active = false;
}
} else if (last_render_time_in_us > (max_render_time_in_us + in_out_vrr->btr.margin_in_us / 2)) {
/* Enter Below the Range */
if (!in_out_vrr->btr.btr_active) {
in_out_vrr->btr.btr_active = true;
}
}
/* BTR set to "not active" so disengage */
if (!in_out_vrr->btr.btr_active) {
in_out_vrr->btr.inserted_duration_in_us = 0;
in_out_vrr->btr.frames_to_insert = 0;
in_out_vrr->btr.frame_counter = 0;
/* Restore FreeSync */
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 =
mod_freesync_calc_v_total_from_refresh(stream,
in_out_vrr->min_refresh_in_uhz);
/* BTR set to "active" so engage */
} else {
/* Calculate number of midPoint frames that could fit within
* the render time interval - take ceil of this value
*/
mid_point_frames_ceil = (last_render_time_in_us +
in_out_vrr->btr.mid_point_in_us - 1) /
in_out_vrr->btr.mid_point_in_us;
if (mid_point_frames_ceil > 0) {
frame_time_in_us = last_render_time_in_us /
mid_point_frames_ceil;
delta_from_mid_point_in_us_1 =
(in_out_vrr->btr.mid_point_in_us >
frame_time_in_us) ?
(in_out_vrr->btr.mid_point_in_us - frame_time_in_us) :
(frame_time_in_us - in_out_vrr->btr.mid_point_in_us);
}
/* Calculate number of midPoint frames that could fit within
* the render time interval - take floor of this value
*/
mid_point_frames_floor = last_render_time_in_us /
in_out_vrr->btr.mid_point_in_us;
if (mid_point_frames_floor > 0) {
frame_time_in_us = last_render_time_in_us /
mid_point_frames_floor;
delta_from_mid_point_in_us_2 =
(in_out_vrr->btr.mid_point_in_us >
frame_time_in_us) ?
(in_out_vrr->btr.mid_point_in_us - frame_time_in_us) :
(frame_time_in_us - in_out_vrr->btr.mid_point_in_us);
}
/* Choose number of frames to insert based on how close it
* can get to the mid point of the variable range.
* - Delta for CEIL: delta_from_mid_point_in_us_1
* - Delta for FLOOR: delta_from_mid_point_in_us_2
*/
if (mid_point_frames_ceil &&
(last_render_time_in_us / mid_point_frames_ceil) <
in_out_vrr->min_duration_in_us) {
/* Check for out of range.
* If using CEIL produces a value that is out of range,
* then we are forced to use FLOOR.
*/
frames_to_insert = mid_point_frames_floor;
} else if (mid_point_frames_floor < 2) {
/* Check if FLOOR would result in non-LFC. In this case
* choose to use CEIL
*/
frames_to_insert = mid_point_frames_ceil;
} else if (delta_from_mid_point_in_us_1 < delta_from_mid_point_in_us_2) {
/* If choosing CEIL results in a frame duration that is
* closer to the mid point of the range.
* Choose CEIL
*/
frames_to_insert = mid_point_frames_ceil;
} else {
/* If choosing FLOOR results in a frame duration that is
* closer to the mid point of the range.
* Choose FLOOR
*/
frames_to_insert = mid_point_frames_floor;
}
/* Prefer current frame multiplier when BTR is enabled unless it drifts
* too far from the midpoint
*/
if (delta_from_mid_point_in_us_1 < delta_from_mid_point_in_us_2) {
delta_from_mid_point_delta_in_us = delta_from_mid_point_in_us_2 -
delta_from_mid_point_in_us_1;
} else {
delta_from_mid_point_delta_in_us = delta_from_mid_point_in_us_1 -
delta_from_mid_point_in_us_2;
}
if (in_out_vrr->btr.frames_to_insert != 0 &&
delta_from_mid_point_delta_in_us < BTR_DRIFT_MARGIN) {
if (((last_render_time_in_us / in_out_vrr->btr.frames_to_insert) <
max_render_time_in_us) &&
((last_render_time_in_us / in_out_vrr->btr.frames_to_insert) >
in_out_vrr->min_duration_in_us))
frames_to_insert = in_out_vrr->btr.frames_to_insert;
}
/* Either we've calculated the number of frames to insert,
* or we need to insert min duration frames
*/
if (frames_to_insert &&
(last_render_time_in_us / frames_to_insert) <
in_out_vrr->min_duration_in_us){
frames_to_insert -= (frames_to_insert > 1) ?
1 : 0;
}
if (frames_to_insert > 0)
inserted_frame_duration_in_us = last_render_time_in_us /
frames_to_insert;
if (inserted_frame_duration_in_us < in_out_vrr->min_duration_in_us)
inserted_frame_duration_in_us = in_out_vrr->min_duration_in_us;
/* Cache the calculated variables */
in_out_vrr->btr.inserted_duration_in_us =
inserted_frame_duration_in_us;
in_out_vrr->btr.frames_to_insert = frames_to_insert;
in_out_vrr->btr.frame_counter = frames_to_insert;
}
}
static void apply_fixed_refresh(struct core_freesync *core_freesync,
const struct dc_stream_state *stream,
unsigned int last_render_time_in_us,
struct mod_vrr_params *in_out_vrr)
{
bool update = false;
unsigned int max_render_time_in_us = in_out_vrr->max_duration_in_us;
/* Compute the exit refresh rate and exit frame duration */
unsigned int exit_refresh_rate_in_milli_hz = ((1000000000/max_render_time_in_us)
+ (1000*FIXED_REFRESH_EXIT_MARGIN_IN_HZ));
unsigned int exit_frame_duration_in_us = 1000000000/exit_refresh_rate_in_milli_hz;
if (last_render_time_in_us < exit_frame_duration_in_us) {
/* Exit Fixed Refresh mode */
if (in_out_vrr->fixed.fixed_active) {
in_out_vrr->fixed.frame_counter++;
if (in_out_vrr->fixed.frame_counter >
FIXED_REFRESH_EXIT_FRAME_COUNT) {
in_out_vrr->fixed.frame_counter = 0;
in_out_vrr->fixed.fixed_active = false;
in_out_vrr->fixed.target_refresh_in_uhz = 0;
update = true;
}
} else
in_out_vrr->fixed.frame_counter = 0;
} else if (last_render_time_in_us > max_render_time_in_us) {
/* Enter Fixed Refresh mode */
if (!in_out_vrr->fixed.fixed_active) {
in_out_vrr->fixed.frame_counter++;
if (in_out_vrr->fixed.frame_counter >
FIXED_REFRESH_ENTER_FRAME_COUNT) {
in_out_vrr->fixed.frame_counter = 0;
in_out_vrr->fixed.fixed_active = true;
in_out_vrr->fixed.target_refresh_in_uhz =
in_out_vrr->max_refresh_in_uhz;
update = true;
}
} else
in_out_vrr->fixed.frame_counter = 0;
}
if (update) {
if (in_out_vrr->fixed.fixed_active) {
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;
} else {
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 =
mod_freesync_calc_v_total_from_refresh(stream,
in_out_vrr->min_refresh_in_uhz);
}
}
}
static bool vrr_settings_require_update(struct core_freesync *core_freesync,
struct mod_freesync_config *in_config,
unsigned int min_refresh_in_uhz,
unsigned int max_refresh_in_uhz,
struct mod_vrr_params *in_vrr)
{
if (in_vrr->state != in_config->state) {
return true;
} else if (in_vrr->state == VRR_STATE_ACTIVE_FIXED &&
in_vrr->fixed.target_refresh_in_uhz !=
in_config->fixed_refresh_in_uhz) {
return true;
} else if (in_vrr->min_refresh_in_uhz != min_refresh_in_uhz) {
return true;
} else if (in_vrr->max_refresh_in_uhz != max_refresh_in_uhz) {
return true;
}
return false;
}
bool mod_freesync_get_vmin_vmax(struct mod_freesync *mod_freesync,
const struct dc_stream_state *stream,
unsigned int *vmin,
unsigned int *vmax)
{
*vmin = stream->adjust.v_total_min;
*vmax = stream->adjust.v_total_max;
return true;
}
bool mod_freesync_get_v_position(struct mod_freesync *mod_freesync,
struct dc_stream_state *stream,
unsigned int *nom_v_pos,
unsigned int *v_pos)
{
struct core_freesync *core_freesync = NULL;
struct crtc_position position;
if (mod_freesync == NULL)
return false;
core_freesync = MOD_FREESYNC_TO_CORE(mod_freesync);
if (dc_stream_get_crtc_position(core_freesync->dc, &stream, 1,
&position.vertical_count,
&position.nominal_vcount)) {
*nom_v_pos = position.nominal_vcount;
*v_pos = position.vertical_count;
return true;
}
return false;
}
static void build_vrr_infopacket_data_v1(const struct mod_vrr_params *vrr,
struct dc_info_packet *infopacket,
bool freesync_on_desktop)
{
/* PB1 = 0x1A (24bit AMD IEEE OUI (0x00001A) - Byte 0) */
infopacket->sb[1] = 0x1A;
/* PB2 = 0x00 (24bit AMD IEEE OUI (0x00001A) - Byte 1) */
infopacket->sb[2] = 0x00;
/* PB3 = 0x00 (24bit AMD IEEE OUI (0x00001A) - Byte 2) */
infopacket->sb[3] = 0x00;
/* PB4 = Reserved */
/* PB5 = Reserved */
/* PB6 = [Bits 7:3 = Reserved] */
/* PB6 = [Bit 0 = FreeSync Supported] */
if (vrr->state != VRR_STATE_UNSUPPORTED)
infopacket->sb[6] |= 0x01;
/* PB6 = [Bit 1 = FreeSync Enabled] */
if (vrr->state != VRR_STATE_DISABLED &&
vrr->state != VRR_STATE_UNSUPPORTED)
infopacket->sb[6] |= 0x02;
if (freesync_on_desktop) {
/* PB6 = [Bit 2 = FreeSync Active] */
if (vrr->state != VRR_STATE_DISABLED &&
vrr->state != VRR_STATE_UNSUPPORTED)
infopacket->sb[6] |= 0x04;
} else {
if (vrr->state == VRR_STATE_ACTIVE_VARIABLE ||
vrr->state == VRR_STATE_ACTIVE_FIXED)
infopacket->sb[6] |= 0x04;
}
// For v1 & 2 infoframes program nominal if non-fs mode, otherwise full range
/* PB7 = FreeSync Minimum refresh rate (Hz) */
if (vrr->state == VRR_STATE_ACTIVE_VARIABLE ||
vrr->state == VRR_STATE_ACTIVE_FIXED) {
infopacket->sb[7] = (unsigned char)((vrr->min_refresh_in_uhz + 500000) / 1000000);
} else {
infopacket->sb[7] = (unsigned char)((vrr->max_refresh_in_uhz + 500000) / 1000000);
}
/* PB8 = FreeSync Maximum refresh rate (Hz)
* Note: We should never go above the field rate of the mode timing set.
*/
infopacket->sb[8] = (unsigned char)((vrr->max_refresh_in_uhz + 500000) / 1000000);
}
static void build_vrr_infopacket_data_v3(const struct mod_vrr_params *vrr,
struct dc_info_packet *infopacket)
{
unsigned int min_refresh;
unsigned int max_refresh;
unsigned int fixed_refresh;
unsigned int min_programmed;
unsigned int max_programmed;
/* PB1 = 0x1A (24bit AMD IEEE OUI (0x00001A) - Byte 0) */
infopacket->sb[1] = 0x1A;
/* PB2 = 0x00 (24bit AMD IEEE OUI (0x00001A) - Byte 1) */
infopacket->sb[2] = 0x00;
/* PB3 = 0x00 (24bit AMD IEEE OUI (0x00001A) - Byte 2) */
infopacket->sb[3] = 0x00;
/* PB4 = Reserved */
/* PB5 = Reserved */
/* PB6 = [Bits 7:3 = Reserved] */
/* PB6 = [Bit 0 = FreeSync Supported] */
if (vrr->state != VRR_STATE_UNSUPPORTED)
infopacket->sb[6] |= 0x01;
/* PB6 = [Bit 1 = FreeSync Enabled] */
if (vrr->state != VRR_STATE_DISABLED &&
vrr->state != VRR_STATE_UNSUPPORTED)
infopacket->sb[6] |= 0x02;
/* PB6 = [Bit 2 = FreeSync Active] */
if (vrr->state == VRR_STATE_ACTIVE_VARIABLE ||
vrr->state == VRR_STATE_ACTIVE_FIXED)
infopacket->sb[6] |= 0x04;
min_refresh = (vrr->min_refresh_in_uhz + 500000) / 1000000;
max_refresh = (vrr->max_refresh_in_uhz + 500000) / 1000000;
fixed_refresh = (vrr->fixed_refresh_in_uhz + 500000) / 1000000;
min_programmed = (vrr->state == VRR_STATE_ACTIVE_FIXED) ? fixed_refresh :
(vrr->state == VRR_STATE_ACTIVE_VARIABLE) ? min_refresh :
(vrr->state == VRR_STATE_INACTIVE) ? min_refresh :
max_refresh; // Non-fs case, program nominal range
max_programmed = (vrr->state == VRR_STATE_ACTIVE_FIXED) ? fixed_refresh :
(vrr->state == VRR_STATE_ACTIVE_VARIABLE) ? max_refresh :
max_refresh;// Non-fs case, program nominal range
/* PB7 = FreeSync Minimum refresh rate (Hz) */
infopacket->sb[7] = min_programmed & 0xFF;
/* PB8 = FreeSync Maximum refresh rate (Hz) */
infopacket->sb[8] = max_programmed & 0xFF;
/* PB11 : MSB FreeSync Minimum refresh rate [Hz] - bits 9:8 */
infopacket->sb[11] = (min_programmed >> 8) & 0x03;
/* PB12 : MSB FreeSync Maximum refresh rate [Hz] - bits 9:8 */
infopacket->sb[12] = (max_programmed >> 8) & 0x03;
/* PB16 : Reserved bits 7:1, FixedRate bit 0 */
infopacket->sb[16] = (vrr->state == VRR_STATE_ACTIVE_FIXED) ? 1 : 0;
}
static void build_vrr_infopacket_fs2_data(enum color_transfer_func app_tf,
struct dc_info_packet *infopacket)
{
if (app_tf != TRANSFER_FUNC_UNKNOWN) {
infopacket->valid = true;
infopacket->sb[6] |= 0x08; // PB6 = [Bit 3 = Native Color Active]
if (app_tf == TRANSFER_FUNC_GAMMA_22) {
infopacket->sb[9] |= 0x04; // PB6 = [Bit 2 = Gamma 2.2 EOTF Active]
}
}
}
static void build_vrr_infopacket_header_v1(enum signal_type signal,
struct dc_info_packet *infopacket,
unsigned int *payload_size)
{
if (dc_is_hdmi_signal(signal)) {
/* HEADER */
/* HB0 = Packet Type = 0x83 (Source Product
* Descriptor InfoFrame)
*/
infopacket->hb0 = DC_HDMI_INFOFRAME_TYPE_SPD;
/* HB1 = Version = 0x01 */
infopacket->hb1 = 0x01;
/* HB2 = [Bits 7:5 = 0] [Bits 4:0 = Length = 0x08] */
infopacket->hb2 = 0x08;
*payload_size = 0x08;
} else if (dc_is_dp_signal(signal)) {
/* HEADER */
/* HB0 = Secondary-data Packet ID = 0 - Only non-zero
* when used to associate audio related info packets
*/
infopacket->hb0 = 0x00;
/* HB1 = Packet Type = 0x83 (Source Product
* Descriptor InfoFrame)
*/
infopacket->hb1 = DC_HDMI_INFOFRAME_TYPE_SPD;
/* HB2 = [Bits 7:0 = Least significant eight bits -
* For INFOFRAME, the value must be 1Bh]
*/
infopacket->hb2 = 0x1B;
/* HB3 = [Bits 7:2 = INFOFRAME SDP Version Number = 0x1]
* [Bits 1:0 = Most significant two bits = 0x00]
*/
infopacket->hb3 = 0x04;
*payload_size = 0x1B;
}
}
static void build_vrr_infopacket_header_v2(enum signal_type signal,
struct dc_info_packet *infopacket,
unsigned int *payload_size)
{
if (dc_is_hdmi_signal(signal)) {
/* HEADER */
/* HB0 = Packet Type = 0x83 (Source Product
* Descriptor InfoFrame)
*/
infopacket->hb0 = DC_HDMI_INFOFRAME_TYPE_SPD;
/* HB1 = Version = 0x02 */
infopacket->hb1 = 0x02;
/* HB2 = [Bits 7:5 = 0] [Bits 4:0 = Length = 0x09] */
infopacket->hb2 = 0x09;
*payload_size = 0x09;
} else if (dc_is_dp_signal(signal)) {
/* HEADER */
/* HB0 = Secondary-data Packet ID = 0 - Only non-zero
* when used to associate audio related info packets
*/
infopacket->hb0 = 0x00;
/* HB1 = Packet Type = 0x83 (Source Product
* Descriptor InfoFrame)
*/
infopacket->hb1 = DC_HDMI_INFOFRAME_TYPE_SPD;
/* HB2 = [Bits 7:0 = Least significant eight bits -
* For INFOFRAME, the value must be 1Bh]
*/
infopacket->hb2 = 0x1B;
/* HB3 = [Bits 7:2 = INFOFRAME SDP Version Number = 0x2]
* [Bits 1:0 = Most significant two bits = 0x00]
*/
infopacket->hb3 = 0x08;
*payload_size = 0x1B;
}
}
static void build_vrr_infopacket_header_v3(enum signal_type signal,
struct dc_info_packet *infopacket,
unsigned int *payload_size)
{
unsigned char version;
version = 3;
if (dc_is_hdmi_signal(signal)) {
/* HEADER */
/* HB0 = Packet Type = 0x83 (Source Product
* Descriptor InfoFrame)
*/
infopacket->hb0 = DC_HDMI_INFOFRAME_TYPE_SPD;
/* HB1 = Version = 0x03 */
infopacket->hb1 = version;
/* HB2 = [Bits 7:5 = 0] [Bits 4:0 = Length] */
infopacket->hb2 = 0x10;
*payload_size = 0x10;
} else if (dc_is_dp_signal(signal)) {
/* HEADER */
/* HB0 = Secondary-data Packet ID = 0 - Only non-zero
* when used to associate audio related info packets
*/
infopacket->hb0 = 0x00;
/* HB1 = Packet Type = 0x83 (Source Product
* Descriptor InfoFrame)
*/
infopacket->hb1 = DC_HDMI_INFOFRAME_TYPE_SPD;
/* HB2 = [Bits 7:0 = Least significant eight bits -
* For INFOFRAME, the value must be 1Bh]
*/
infopacket->hb2 = 0x1B;
/* HB3 = [Bits 7:2 = INFOFRAME SDP Version Number = 0x2]
* [Bits 1:0 = Most significant two bits = 0x00]
*/
infopacket->hb3 = (version & 0x3F) << 2;
*payload_size = 0x1B;
}
}
static void build_vrr_infopacket_checksum(unsigned int *payload_size,
struct dc_info_packet *infopacket)
{
/* Calculate checksum */
unsigned int idx = 0;
unsigned char checksum = 0;
checksum += infopacket->hb0;
checksum += infopacket->hb1;
checksum += infopacket->hb2;
checksum += infopacket->hb3;
for (idx = 1; idx <= *payload_size; idx++)
checksum += infopacket->sb[idx];
/* PB0 = Checksum (one byte complement) */
infopacket->sb[0] = (unsigned char)(0x100 - checksum);
infopacket->valid = true;
}
static void build_vrr_infopacket_v1(enum signal_type signal,
const struct mod_vrr_params *vrr,
struct dc_info_packet *infopacket,
bool freesync_on_desktop)
{
/* SPD info packet for FreeSync */
unsigned int payload_size = 0;
build_vrr_infopacket_header_v1(signal, infopacket, &payload_size);
build_vrr_infopacket_data_v1(vrr, infopacket, freesync_on_desktop);
build_vrr_infopacket_checksum(&payload_size, infopacket);
infopacket->valid = true;
}
static void build_vrr_infopacket_v2(enum signal_type signal,
const struct mod_vrr_params *vrr,
enum color_transfer_func app_tf,
struct dc_info_packet *infopacket,
bool freesync_on_desktop)
{
unsigned int payload_size = 0;
build_vrr_infopacket_header_v2(signal, infopacket, &payload_size);
build_vrr_infopacket_data_v1(vrr, infopacket, freesync_on_desktop);
build_vrr_infopacket_fs2_data(app_tf, infopacket);
build_vrr_infopacket_checksum(&payload_size, infopacket);
infopacket->valid = true;
}
#ifndef TRIM_FSFT
static void build_vrr_infopacket_fast_transport_data(
bool ftActive,
unsigned int ftOutputRate,
struct dc_info_packet *infopacket)
{
/* PB9 : bit7 - fast transport Active*/
unsigned char activeBit = (ftActive) ? 1 << 7 : 0;
infopacket->sb[1] &= ~activeBit; //clear bit
infopacket->sb[1] |= activeBit; //set bit
/* PB13 : Target Output Pixel Rate [kHz] - bits 7:0 */
infopacket->sb[13] = ftOutputRate & 0xFF;
/* PB14 : Target Output Pixel Rate [kHz] - bits 15:8 */
infopacket->sb[14] = (ftOutputRate >> 8) & 0xFF;
/* PB15 : Target Output Pixel Rate [kHz] - bits 23:16 */
infopacket->sb[15] = (ftOutputRate >> 16) & 0xFF;
}
#endif
static void build_vrr_infopacket_v3(enum signal_type signal,
const struct mod_vrr_params *vrr,
#ifndef TRIM_FSFT
bool ftActive, unsigned int ftOutputRate,
#endif
enum color_transfer_func app_tf,
struct dc_info_packet *infopacket)
{
unsigned int payload_size = 0;
build_vrr_infopacket_header_v3(signal, infopacket, &payload_size);
build_vrr_infopacket_data_v3(vrr, infopacket);
build_vrr_infopacket_fs2_data(app_tf, infopacket);
#ifndef TRIM_FSFT
build_vrr_infopacket_fast_transport_data(
ftActive,
ftOutputRate,
infopacket);
#endif
build_vrr_infopacket_checksum(&payload_size, infopacket);
infopacket->valid = true;
}
static void build_vrr_infopacket_sdp_v1_3(enum vrr_packet_type packet_type,
struct dc_info_packet *infopacket)
{
uint8_t idx = 0, size = 0;
size = ((packet_type == PACKET_TYPE_FS_V1) ? 0x08 :
(packet_type == PACKET_TYPE_FS_V3) ? 0x10 :
0x09);
for (idx = infopacket->hb2; idx > 1; idx--) // Data Byte Count: 0x1B
infopacket->sb[idx] = infopacket->sb[idx-1];
infopacket->sb[1] = size; // Length
infopacket->sb[0] = (infopacket->hb3 >> 2) & 0x3F;//Version
infopacket->hb3 = (0x13 << 2); // Header,SDP 1.3
infopacket->hb2 = 0x1D;
}
void mod_freesync_build_vrr_infopacket(struct mod_freesync *mod_freesync,
const struct dc_stream_state *stream,
const struct mod_vrr_params *vrr,
enum vrr_packet_type packet_type,
enum color_transfer_func app_tf,
struct dc_info_packet *infopacket,
bool pack_sdp_v1_3)
{
/* SPD info packet for FreeSync
* VTEM info packet for HdmiVRR
* Check if Freesync is supported. Return if false. If true,
* set the corresponding bit in the info packet
*/
if (!vrr->send_info_frame)
return;
switch (packet_type) {
case PACKET_TYPE_FS_V3:
#ifndef TRIM_FSFT
// always populate with pixel rate.
build_vrr_infopacket_v3(
stream->signal, vrr,
stream->timing.flags.FAST_TRANSPORT,
(stream->timing.flags.FAST_TRANSPORT) ?
stream->timing.fast_transport_output_rate_100hz :
stream->timing.pix_clk_100hz,
app_tf, infopacket);
#else
build_vrr_infopacket_v3(stream->signal, vrr, app_tf, infopacket);
#endif
break;
case PACKET_TYPE_FS_V2:
build_vrr_infopacket_v2(stream->signal, vrr, app_tf, infopacket, stream->freesync_on_desktop);
break;
case PACKET_TYPE_VRR:
case PACKET_TYPE_FS_V1:
default:
build_vrr_infopacket_v1(stream->signal, vrr, infopacket, stream->freesync_on_desktop);
}
if (true == pack_sdp_v1_3 &&
true == dc_is_dp_signal(stream->signal) &&
packet_type != PACKET_TYPE_VRR &&
packet_type != PACKET_TYPE_VTEM)
build_vrr_infopacket_sdp_v1_3(packet_type, infopacket);
}
void mod_freesync_build_vrr_params(struct mod_freesync *mod_freesync,
const struct dc_stream_state *stream,
struct mod_freesync_config *in_config,
struct mod_vrr_params *in_out_vrr)
{
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;
if (mod_freesync == NULL)
return;
core_freesync = MOD_FREESYNC_TO_CORE(mod_freesync);
/* Calculate nominal field rate for stream */
nominal_field_rate_in_uhz =
mod_freesync_calc_nominal_field_rate(stream);
min_refresh_in_uhz = in_config->min_refresh_in_uhz;
max_refresh_in_uhz = in_config->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 > 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,
in_out_vrr))
return;
in_out_vrr->state = in_config->state;
in_out_vrr->send_info_frame = in_config->vsif_supported;
if (in_config->state == VRR_STATE_UNSUPPORTED) {
in_out_vrr->state = VRR_STATE_UNSUPPORTED;
in_out_vrr->supported = false;
in_out_vrr->adjust.v_total_min = stream->timing.v_total;
in_out_vrr->adjust.v_total_max = stream->timing.v_total;
return;
} else {
in_out_vrr->min_refresh_in_uhz = (unsigned int)min_refresh_in_uhz;
in_out_vrr->max_duration_in_us =
calc_duration_in_us_from_refresh_in_uhz(
(unsigned int)min_refresh_in_uhz);
in_out_vrr->max_refresh_in_uhz = (unsigned int)max_refresh_in_uhz;
in_out_vrr->min_duration_in_us =
calc_duration_in_us_from_refresh_in_uhz(
(unsigned int)max_refresh_in_uhz);
if (in_config->state == VRR_STATE_ACTIVE_FIXED)
in_out_vrr->fixed_refresh_in_uhz = in_config->fixed_refresh_in_uhz;
else
in_out_vrr->fixed_refresh_in_uhz = 0;
refresh_range = div_u64(in_out_vrr->max_refresh_in_uhz + 500000, 1000000) -
+ div_u64(in_out_vrr->min_refresh_in_uhz + 500000, 1000000);
in_out_vrr->supported = true;
}
in_out_vrr->fixed.ramping_active = in_config->ramping;
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))
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;
in_out_vrr->btr.frames_to_insert = 0;
in_out_vrr->btr.frame_counter = 0;
in_out_vrr->fixed.fixed_active = false;
in_out_vrr->fixed.target_refresh_in_uhz = 0;
in_out_vrr->btr.mid_point_in_us =
(in_out_vrr->min_duration_in_us +
in_out_vrr->max_duration_in_us) / 2;
if (in_out_vrr->state == VRR_STATE_UNSUPPORTED) {
in_out_vrr->adjust.v_total_min = stream->timing.v_total;
in_out_vrr->adjust.v_total_max = stream->timing.v_total;
} else if (in_out_vrr->state == VRR_STATE_DISABLED) {
in_out_vrr->adjust.v_total_min = stream->timing.v_total;
in_out_vrr->adjust.v_total_max = stream->timing.v_total;
} else if (in_out_vrr->state == VRR_STATE_INACTIVE) {
in_out_vrr->adjust.v_total_min = stream->timing.v_total;
in_out_vrr->adjust.v_total_max = stream->timing.v_total;
} else if (in_out_vrr->state == VRR_STATE_ACTIVE_VARIABLE &&
refresh_range >= MIN_REFRESH_RANGE) {
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 =
mod_freesync_calc_v_total_from_refresh(stream,
in_out_vrr->min_refresh_in_uhz);
} else if (in_out_vrr->state == VRR_STATE_ACTIVE_FIXED) {
in_out_vrr->fixed.target_refresh_in_uhz =
in_out_vrr->fixed_refresh_in_uhz;
if (in_out_vrr->fixed.ramping_active &&
in_out_vrr->fixed.fixed_active) {
/* Do not update vtotals if ramping is already active
* in order to continue ramp from current refresh.
*/
in_out_vrr->fixed.fixed_active = true;
} else {
in_out_vrr->fixed.fixed_active = true;
in_out_vrr->adjust.v_total_min =
mod_freesync_calc_v_total_from_refresh(stream,
in_out_vrr->fixed.target_refresh_in_uhz);
in_out_vrr->adjust.v_total_max =
in_out_vrr->adjust.v_total_min;
}
} else {
in_out_vrr->state = VRR_STATE_INACTIVE;
in_out_vrr->adjust.v_total_min = stream->timing.v_total;
in_out_vrr->adjust.v_total_max = stream->timing.v_total;
}
}
void mod_freesync_handle_preflip(struct mod_freesync *mod_freesync,
const struct dc_plane_state *plane,
const struct dc_stream_state *stream,
unsigned int curr_time_stamp_in_us,
struct mod_vrr_params *in_out_vrr)
{
struct core_freesync *core_freesync = NULL;
unsigned int last_render_time_in_us = 0;
unsigned int average_render_time_in_us = 0;
if (mod_freesync == NULL)
return;
core_freesync = MOD_FREESYNC_TO_CORE(mod_freesync);
if (in_out_vrr->supported &&
in_out_vrr->state == VRR_STATE_ACTIVE_VARIABLE) {
unsigned int i = 0;
unsigned int oldest_index = plane->time.index + 1;
if (oldest_index >= DC_PLANE_UPDATE_TIMES_MAX)
oldest_index = 0;
last_render_time_in_us = curr_time_stamp_in_us -
plane->time.prev_update_time_in_us;
/* Sum off all entries except oldest one */
for (i = 0; i < DC_PLANE_UPDATE_TIMES_MAX; i++) {
average_render_time_in_us +=
plane->time.time_elapsed_in_us[i];
}
average_render_time_in_us -=
plane->time.time_elapsed_in_us[oldest_index];
/* Add render time for current flip */
average_render_time_in_us += last_render_time_in_us;
average_render_time_in_us /= DC_PLANE_UPDATE_TIMES_MAX;
if (in_out_vrr->btr.btr_enabled) {
apply_below_the_range(core_freesync,
stream,
last_render_time_in_us,
in_out_vrr);
} else {
apply_fixed_refresh(core_freesync,
stream,
last_render_time_in_us,
in_out_vrr);
}
}
}
void mod_freesync_handle_v_update(struct mod_freesync *mod_freesync,
const struct dc_stream_state *stream,
struct mod_vrr_params *in_out_vrr)
{
struct core_freesync *core_freesync = NULL;
if ((mod_freesync == NULL) || (stream == NULL) || (in_out_vrr == NULL))
return;
core_freesync = MOD_FREESYNC_TO_CORE(mod_freesync);
if (in_out_vrr->supported == false)
return;
/* Below the Range Logic */
/* Only execute if in fullscreen mode */
if (in_out_vrr->state == VRR_STATE_ACTIVE_VARIABLE &&
in_out_vrr->btr.btr_active) {
/* TODO: pass in flag for Pre-DCE12 ASIC
* in order for frame variable duration to take affect,
* it needs to be done one VSYNC early, which is at
* frameCounter == 1.
* For DCE12 and newer updates to V_TOTAL_MIN/MAX
* will take affect on current frame
*/
if (in_out_vrr->btr.frames_to_insert ==
in_out_vrr->btr.frame_counter) {
in_out_vrr->adjust.v_total_min =
calc_v_total_from_duration(stream,
in_out_vrr,
in_out_vrr->btr.inserted_duration_in_us);
in_out_vrr->adjust.v_total_max =
in_out_vrr->adjust.v_total_min;
}
if (in_out_vrr->btr.frame_counter > 0)
in_out_vrr->btr.frame_counter--;
/* Restore FreeSync */
if (in_out_vrr->btr.frame_counter == 0) {
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 =
mod_freesync_calc_v_total_from_refresh(stream,
in_out_vrr->min_refresh_in_uhz);
}
}
/* If in fullscreen freesync mode or in video, do not program
* static screen ramp values
*/
if (in_out_vrr->state == VRR_STATE_ACTIVE_VARIABLE)
in_out_vrr->fixed.ramping_active = false;
/* Gradual Static Screen Ramping Logic
* Execute if ramp is active and user enabled freesync static screen
*/
if (in_out_vrr->state == VRR_STATE_ACTIVE_FIXED &&
in_out_vrr->fixed.ramping_active) {
update_v_total_for_static_ramp(
core_freesync, stream, in_out_vrr);
}
}
void mod_freesync_get_settings(struct mod_freesync *mod_freesync,
const struct mod_vrr_params *vrr,
unsigned int *v_total_min, unsigned int *v_total_max,
unsigned int *event_triggers,
unsigned int *window_min, unsigned int *window_max,
unsigned int *lfc_mid_point_in_us,
unsigned int *inserted_frames,
unsigned int *inserted_duration_in_us)
{
if (mod_freesync == NULL)
return;
if (vrr->supported) {
*v_total_min = vrr->adjust.v_total_min;
*v_total_max = vrr->adjust.v_total_max;
*event_triggers = 0;
*lfc_mid_point_in_us = vrr->btr.mid_point_in_us;
*inserted_frames = vrr->btr.frames_to_insert;
*inserted_duration_in_us = vrr->btr.inserted_duration_in_us;
}
}
unsigned long long mod_freesync_calc_nominal_field_rate(
const struct dc_stream_state *stream)
{
unsigned long long nominal_field_rate_in_uhz = 0;
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;
nominal_field_rate_in_uhz *= 100000000ULL;
nominal_field_rate_in_uhz = div_u64(nominal_field_rate_in_uhz, total);
return nominal_field_rate_in_uhz;
}
unsigned long long mod_freesync_calc_field_rate_from_timing(
unsigned int vtotal, unsigned int htotal, unsigned int pix_clk)
{
unsigned long long field_rate_in_uhz = 0;
unsigned int total = htotal * vtotal;
/* Calculate nominal field rate for stream, rounded up to nearest integer */
field_rate_in_uhz = pix_clk;
field_rate_in_uhz *= 1000000ULL;
field_rate_in_uhz = div_u64(field_rate_in_uhz, total);
return field_rate_in_uhz;
}
bool mod_freesync_is_valid_range(uint32_t min_refresh_cap_in_uhz,
uint32_t max_refresh_cap_in_uhz,
uint32_t nominal_field_rate_in_uhz)
{
/* Typically nominal refresh calculated can have some fractional part.
* Allow for some rounding error of actual video timing by taking floor
* of caps and request. Round the nominal refresh rate.
*
* Dividing will convert everything to units in Hz although input
* variable name is in uHz!
*
* Also note, this takes care of rounding error on the nominal refresh
* so by rounding error we only expect it to be off by a small amount,
* such as < 0.1 Hz. i.e. 143.9xxx or 144.1xxx.
*
* Example 1. Caps Min = 40 Hz, Max = 144 Hz
* Request Min = 40 Hz, Max = 144 Hz
* Nominal = 143.5x Hz rounded to 144 Hz
* This function should allow this as valid request
*
* Example 2. Caps Min = 40 Hz, Max = 144 Hz
* Request Min = 40 Hz, Max = 144 Hz
* Nominal = 144.4x Hz rounded to 144 Hz
* This function should allow this as valid request
*
* Example 3. Caps Min = 40 Hz, Max = 144 Hz
* Request Min = 40 Hz, Max = 144 Hz
* Nominal = 120.xx Hz rounded to 120 Hz
* This function should return NOT valid since the requested
* max is greater than current timing's nominal
*
* Example 4. Caps Min = 40 Hz, Max = 120 Hz
* Request Min = 40 Hz, Max = 120 Hz
* Nominal = 144.xx Hz rounded to 144 Hz
* This function should return NOT valid since the nominal
* is greater than the capability's max refresh
*/
nominal_field_rate_in_uhz =
div_u64(nominal_field_rate_in_uhz + 500000, 1000000);
min_refresh_cap_in_uhz /= 1000000;
max_refresh_cap_in_uhz /= 1000000;
/* Check nominal is within range */
if (nominal_field_rate_in_uhz > max_refresh_cap_in_uhz ||
nominal_field_rate_in_uhz < min_refresh_cap_in_uhz)
return false;
/* If nominal is less than max, limit the max allowed refresh rate */
if (nominal_field_rate_in_uhz < max_refresh_cap_in_uhz)
max_refresh_cap_in_uhz = nominal_field_rate_in_uhz;
/* Check min is within range */
if (min_refresh_cap_in_uhz > max_refresh_cap_in_uhz)
return false;
/* For variable range, check for at least 10 Hz range */
if (nominal_field_rate_in_uhz - min_refresh_cap_in_uhz < 10)
return false;
return true;
}