Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
drm/amd/display: add dc interface for query QoS information
[why]
Add support for retrieving Quality of Service (QoS) metrics from dc
to enable performance analysis and bottleneck identification. This provides
benchmark tools with real-time bandwidth and latency measurements from hardware
performance counters, helping diagnose display system performance issues.
[how]
- Add dc_get_qos_info() function to DC layer for unified QoS data retrieval
- Implement hardware sequencer interface with function pointers for QoS
measurements
- Integrate QoS metrics: peak/average bandwidth (Mbps) and max/average
latency (ns)
Reviewed-by: Aric Cyr <aric.cyr@amd.com>
Signed-off-by: Wenjing Liu <wenjing.liu@amd.com>
Signed-off-by: Roman Li <roman.li@amd.com>
Tested-by: Dan Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
authored by
Wenjing Liu
and committed by
Alex Deucher
e4a3133c
c0228872
+97
+24
drivers/gpu/drm/amd/display/dc/core/dc.c
+24
drivers/gpu/drm/amd/display/dc/core/dc.c
···
7091
7091
{
7092
7092
dc_dmub_srv_log_preos_dmcub_info(dc->ctx->dmub_srv);
7093
7093
}
7094
+
7095
+
bool dc_get_qos_info(struct dc *dc, struct dc_qos_info *info)
7096
+
{
7097
+
const struct dc_clocks *clk = &dc->current_state->bw_ctx.bw.dcn.clk;
7098
+
7099
+
memset(info, 0, sizeof(*info));
7100
+
7101
+
// Check if all measurement functions are available
7102
+
if (!dc->hwss.measure_peak_bw_mbps ||
7103
+
!dc->hwss.measure_avg_bw_mbps ||
7104
+
!dc->hwss.measure_max_latency_ns ||
7105
+
!dc->hwss.measure_avg_latency_ns) {
7106
+
return false;
7107
+
}
7108
+
7109
+
// Call measurement functions to get actual values
7110
+
info->actual_peak_bw_in_mbps = dc->hwss.measure_peak_bw_mbps(dc);
7111
+
info->actual_avg_bw_in_mbps = dc->hwss.measure_avg_bw_mbps(dc);
7112
+
info->actual_max_latency_in_ns = dc->hwss.measure_max_latency_ns(dc);
7113
+
info->actual_avg_latency_in_ns = dc->hwss.measure_avg_latency_ns(dc);
7114
+
info->dcn_bandwidth_ub_in_mbps = (uint32_t)(clk->fclk_khz / 1000 * 64);
7115
+
7116
+
return true;
7117
+
}
+36
drivers/gpu/drm/amd/display/dc/dc.h
+36
drivers/gpu/drm/amd/display/dc/dc.h
···
951
951
int min_dcfclk_mhz;
952
952
};
953
953
954
+
struct dc_qos_info {
955
+
uint32_t actual_peak_bw_in_mbps;
956
+
uint32_t qos_bandwidth_lb_in_mbps;
957
+
uint32_t actual_avg_bw_in_mbps;
958
+
uint32_t calculated_avg_bw_in_mbps;
959
+
uint32_t actual_max_latency_in_ns;
960
+
uint32_t qos_max_latency_ub_in_ns;
961
+
uint32_t actual_avg_latency_in_ns;
962
+
uint32_t qos_avg_latency_ub_in_ns;
963
+
uint32_t dcn_bandwidth_ub_in_mbps;
964
+
};
965
+
954
966
struct dc_state;
955
967
struct resource_pool;
956
968
struct dce_hwseq;
···
3333
3321
* Return: true if state was successfully captured, false on error
3334
3322
*/
3335
3323
bool dc_capture_register_software_state(struct dc *dc, struct dc_register_software_state *state);
3324
+
3325
+
/**
3326
+
* dc_get_qos_info() - Retrieve Quality of Service (QoS) information from display core
3327
+
* @dc: DC context containing current display configuration
3328
+
* @info: Pointer to dc_qos_info structure to populate with QoS metrics
3329
+
*
3330
+
* This function retrieves QoS metrics from the display core that can be used by
3331
+
* benchmark tools to analyze display system performance. The function may take
3332
+
* several milliseconds to execute due to hardware measurement requirements.
3333
+
*
3334
+
* QoS information includes:
3335
+
* - Bandwidth bounds (lower limits in Mbps)
3336
+
* - Latency bounds (upper limits in nanoseconds)
3337
+
* - Hardware-measured bandwidth metrics (peak/average in Mbps)
3338
+
* - Hardware-measured latency metrics (maximum/average in nanoseconds)
3339
+
*
3340
+
* The function will populate the provided dc_qos_info structure with current
3341
+
* QoS measurements. If hardware measurement functions are not available for
3342
+
* the current DCN version, the function returns false with zero'd info structure.
3343
+
*
3344
+
* Return: true if QoS information was successfully retrieved, false if measurement
3345
+
* functions are unavailable or hardware measurements cannot be performed
3346
+
*/
3347
+
bool dc_get_qos_info(struct dc *dc, struct dc_qos_info *info);
3336
3348
3337
3349
#endif /* DC_INTERFACE_H_ */
+37
drivers/gpu/drm/amd/display/dc/hwss/hw_sequencer.h
+37
drivers/gpu/drm/amd/display/dc/hwss/hw_sequencer.h
···
1287
1287
void (*get_underflow_debug_data)(const struct dc *dc,
1288
1288
struct timing_generator *tg,
1289
1289
struct dc_underflow_debug_data *out_data);
1290
+
1291
+
/**
1292
+
* measure_peak_bw_mbps - Measure actual peak bandwidth in Mbps
1293
+
* @dc: DC structure
1294
+
*
1295
+
* Returns the measured peak bandwidth value in Mbps from hardware
1296
+
* performance counters or registers.
1297
+
*/
1298
+
uint32_t (*measure_peak_bw_mbps)(struct dc *dc);
1299
+
1300
+
/**
1301
+
* measure_avg_bw_mbps - Measure actual average bandwidth in Mbps
1302
+
* @dc: DC structure
1303
+
*
1304
+
* Returns the measured average bandwidth value in Mbps from hardware
1305
+
* performance counters or registers.
1306
+
*/
1307
+
uint32_t (*measure_avg_bw_mbps)(struct dc *dc);
1308
+
1309
+
/**
1310
+
* measure_max_latency_ns - Measure actual maximum latency in nanoseconds
1311
+
* @dc: DC structure
1312
+
*
1313
+
* Returns the measured maximum latency value in nanoseconds from hardware
1314
+
* performance counters or registers.
1315
+
*/
1316
+
uint32_t (*measure_max_latency_ns)(struct dc *dc);
1317
+
1318
+
/**
1319
+
* measure_avg_latency_ns - Measure actual average latency in nanoseconds
1320
+
* @dc: DC structure
1321
+
*
1322
+
* Returns the measured average latency value in nanoseconds from hardware
1323
+
* performance counters or registers.
1324
+
*/
1325
+
uint32_t (*measure_avg_latency_ns)(struct dc *dc);
1326
+
1290
1327
};
1291
1328
1292
1329
void color_space_to_black_color(