[PATCH 03/20] drm/amd/display: Reduce CPU busy-waiting for long delays
Qingqing Zhuo
qingqing.zhuo at amd.com
Wed Feb 22 06:40:24 UTC 2023
From: Aric Cyr <aric.cyr at amd.com>
[WHY]
udelay should not be used for long waits since it keeps CPU active,
wasting power.
[HOW]
Use fsleep where acceptable to allow CPU cores to be parked by the scheduler.
Reviewed-by: Wenjing Liu <Wenjing.Liu at amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo at amd.com>
Signed-off-by: Aric Cyr <aric.cyr at amd.com>
---
drivers/gpu/drm/amd/display/dc/dce/dce_aux.c | 9 ++-------
drivers/gpu/drm/amd/display/dc/dce/dce_dmcu.c | 2 +-
drivers/gpu/drm/amd/display/dc/dce/dmub_psr.c | 2 +-
drivers/gpu/drm/amd/display/dc/link/link_dpms.c | 4 ++--
.../amd/display/dc/link/protocols/link_dp_capability.c | 8 ++++----
.../drm/amd/display/dc/link/protocols/link_dp_dpia_bw.c | 2 +-
.../drm/amd/display/dc/link/protocols/link_dp_training.c | 7 ++-----
.../display/dc/link/protocols/link_dp_training_dpia.c | 2 +-
.../display/dc/link/protocols/link_edp_panel_control.c | 4 ++--
9 files changed, 16 insertions(+), 24 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/dc/dce/dce_aux.c b/drivers/gpu/drm/amd/display/dc/dce/dce_aux.c
index 140297c8ff55..739298d2dff3 100644
--- a/drivers/gpu/drm/amd/display/dc/dce/dce_aux.c
+++ b/drivers/gpu/drm/amd/display/dc/dce/dce_aux.c
@@ -832,13 +832,8 @@ bool dce_aux_transfer_with_retries(struct ddc_service *ddc,
LOG_FLAG_I2cAux_DceAux,
"dce_aux_transfer_with_retries: payload->defer_delay=%u",
payload->defer_delay);
- if (payload->defer_delay > 1) {
- msleep(payload->defer_delay);
- defer_time_in_ms += payload->defer_delay;
- } else if (payload->defer_delay <= 1) {
- udelay(payload->defer_delay * 1000);
- defer_time_in_ms += payload->defer_delay;
- }
+ fsleep(payload->defer_delay * 1000);
+ defer_time_in_ms += payload->defer_delay;
}
}
break;
diff --git a/drivers/gpu/drm/amd/display/dc/dce/dce_dmcu.c b/drivers/gpu/drm/amd/display/dc/dce/dce_dmcu.c
index d3cc5ec46956..e74266cc0098 100644
--- a/drivers/gpu/drm/amd/display/dc/dce/dce_dmcu.c
+++ b/drivers/gpu/drm/amd/display/dc/dce/dce_dmcu.c
@@ -586,7 +586,7 @@ static void dcn10_dmcu_set_psr_enable(struct dmcu *dmcu, bool enable, bool wait)
if (state == PSR_STATE0)
break;
}
- udelay(500);
+ fsleep(500);
}
/* assert if max retry hit */
diff --git a/drivers/gpu/drm/amd/display/dc/dce/dmub_psr.c b/drivers/gpu/drm/amd/display/dc/dce/dmub_psr.c
index 1e2d2cbe2c37..19440bdf6344 100644
--- a/drivers/gpu/drm/amd/display/dc/dce/dmub_psr.c
+++ b/drivers/gpu/drm/amd/display/dc/dce/dmub_psr.c
@@ -215,7 +215,7 @@ static void dmub_psr_enable(struct dmub_psr *dmub, bool enable, bool wait, uint8
break;
}
- udelay(500);
+ fsleep(500);
}
/* assert if max retry hit */
diff --git a/drivers/gpu/drm/amd/display/dc/link/link_dpms.c b/drivers/gpu/drm/amd/display/dc/link/link_dpms.c
index 257e1c3ba00a..180c92a9f117 100644
--- a/drivers/gpu/drm/amd/display/dc/link/link_dpms.c
+++ b/drivers/gpu/drm/amd/display/dc/link/link_dpms.c
@@ -1153,7 +1153,7 @@ static bool poll_for_allocation_change_trigger(struct dc_link *link)
break;
}
- msleep(5);
+ fsleep(5000);
}
if (result == ACT_FAILED) {
@@ -1640,7 +1640,7 @@ static bool write_128b_132b_sst_payload_allocation_table(
}
}
retries++;
- msleep(5);
+ fsleep(5000);
}
if (!result && retries == max_retries) {
diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c
index d4370856f164..0f2c59807079 100644
--- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c
+++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c
@@ -1005,7 +1005,7 @@ static enum dc_status wake_up_aux_channel(struct dc_link *link)
* signal and may need up to 1 ms before being able to reply.
*/
if (status != DC_OK || dpcd_power_state == DP_SET_POWER_D3) {
- udelay(1000);
+ fsleep(1000);
aux_channel_retry_cnt++;
}
}
@@ -2121,7 +2121,7 @@ static bool dp_verify_link_cap(
if (status == LINK_TRAINING_SUCCESS) {
success = true;
- udelay(1000);
+ fsleep(1000);
if (dc_link_dp_read_hpd_rx_irq_data(link, &irq_data) == DC_OK &&
dc_link_check_link_loss_status(
link,
@@ -2171,7 +2171,7 @@ bool dp_verify_link_cap_with_retries(
success = true;
break;
}
- msleep(10);
+ fsleep(10 * 1000);
}
dp_trace_lt_fail_count_update(link, fail_count, true);
@@ -2231,7 +2231,7 @@ bool dc_link_is_dp_sink_present(struct dc_link *link)
gpio_result = dal_gpio_get_value(ddc->pin_clock, &clock_pin);
ASSERT(gpio_result == GPIO_RESULT_OK);
if (clock_pin)
- udelay(1000);
+ fsleep(1000);
else
break;
} while (retry++ < 3);
diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia_bw.c b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia_bw.c
index f69e681b3b5b..fcb82bb855ed 100644
--- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia_bw.c
+++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia_bw.c
@@ -424,7 +424,7 @@ int dc_link_dp_dpia_handle_usb4_bandwidth_allocation_for_link(struct dc_link *li
timeout--;
else
break;
- udelay(10 * 1000);
+ fsleep(10 * 1000);
} while (!get_cm_response_ready_flag(link));
if (!timeout)
diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.c b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.c
index b48d4d822991..5e613ea2cd3f 100644
--- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.c
+++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.c
@@ -258,10 +258,7 @@ void dp_wait_for_training_aux_rd_interval(
struct dc_link *link,
uint32_t wait_in_micro_secs)
{
- if (wait_in_micro_secs > 1000)
- msleep(wait_in_micro_secs/1000);
- else
- udelay(wait_in_micro_secs);
+ fsleep(wait_in_micro_secs);
DC_LOG_HW_LINK_TRAINING("%s:\n wait = %d\n",
__func__,
@@ -970,7 +967,7 @@ static void dpcd_exit_training_mode(struct dc_link *link, enum dp_link_encoding
if ((core_link_read_dpcd(link, DP_SINK_STATUS, &sink_status, 1) == DC_OK) &&
(sink_status & DP_INTRA_HOP_AUX_REPLY_INDICATION) == 0)
break;
- udelay(1000);
+ fsleep(1000);
}
}
}
diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training_dpia.c b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training_dpia.c
index e60da0532c53..9715fa754d56 100644
--- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training_dpia.c
+++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training_dpia.c
@@ -1035,7 +1035,7 @@ enum link_training_result dc_link_dpia_perform_link_training(
* falling back to lower bandwidth settings possible.
*/
if (result == LINK_TRAINING_SUCCESS) {
- msleep(5);
+ fsleep(5000);
if (!link->is_automated)
result = dp_check_link_loss_status(link, <_settings);
} else if (result == LINK_TRAINING_ABORT)
diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_edp_panel_control.c b/drivers/gpu/drm/amd/display/dc/link/protocols/link_edp_panel_control.c
index 97e02b5b21ae..da7f83835f78 100644
--- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_edp_panel_control.c
+++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_edp_panel_control.c
@@ -325,7 +325,7 @@ bool dc_link_wait_for_t12(struct dc_link *link)
void link_edp_add_delay_for_T9(struct dc_link *link)
{
if (link && link->panel_config.pps.extra_delay_backlight_off > 0)
- udelay(link->panel_config.pps.extra_delay_backlight_off * 1000);
+ fsleep(link->panel_config.pps.extra_delay_backlight_off * 1000);
}
bool link_edp_receiver_ready_T9(struct dc_link *link)
@@ -383,7 +383,7 @@ bool link_edp_receiver_ready_T7(struct dc_link *link)
}
if (link && link->panel_config.pps.extra_t7_ms > 0)
- udelay(link->panel_config.pps.extra_t7_ms * 1000);
+ fsleep(link->panel_config.pps.extra_t7_ms * 1000);
return result;
}
--
2.34.1
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