[Intel-gfx] [PATCH 2/3] drm/dp: reuse the 8b/10b link training delay helpers

Jani Nikula
2021-10-14T15:01:34Z

Reuse the 8b/10b link training delay helpers. Functionally this skips
the check for invalid values for DPCD 1.4 and later at clock recovery
delay (as it's a fixed delay and bypasses the rd_interval) but the same
value will be checked and invalid values reported at channel
equalization.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
drivers/gpu/drm/drm_dp_helper.c | 30 ++++++++++--------------------
1 file changed, 10 insertions(+), 20 deletions(-)

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index f7ebf5974fa7..ada0a1ff262d 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -284,35 +284,25 @@ EXPORT_SYMBOL(drm_dp_read_channel_eq_delay);
void drm_dp_link_train_clock_recovery_delay(const struct drm_dp_aux *aux,
const u8 dpcd[DP_RECEIVER_CAP_SIZE])
{
- unsigned long rd_interval = dpcd[DP_TRAINING_AUX_RD_INTERVAL] &
- DP_TRAINING_AUX_RD_MASK;
+ u8 rd_interval = dpcd[DP_TRAINING_AUX_RD_INTERVAL] &
+ DP_TRAINING_AUX_RD_MASK;
+ int delay_us;

- if (rd_interval > 4)
- drm_dbg_kms(aux->drm_dev, "%s: AUX interval %lu, out of range (max 4)\n",
- aux->name, rd_interval);
-
- if (rd_interval == 0 || dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14)
- rd_interval = 100;
+ if (dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14)
+ delay_us = 100;
else
- rd_interval *= 4 * USEC_PER_MSEC;
+ delay_us = __8b10b_clock_recovery_delay_us(aux, rd_interval);

- usleep_range(rd_interval, rd_interval * 2);
+ usleep_range(delay_us, delay_us * 2);
}
EXPORT_SYMBOL(drm_dp_link_train_clock_recovery_delay);

static void __drm_dp_link_train_channel_eq_delay(const struct drm_dp_aux *aux,
- unsigned long rd_interval)
+ u8 rd_interval)
{
- if (rd_interval > 4)
- drm_dbg_kms(aux->drm_dev, "%s: AUX interval %lu, out of range (max 4)\n",
- aux->name, rd_interval);
-
- if (rd_interval == 0)
- rd_interval = 400;
- else
- rd_interval *= 4 * USEC_PER_MSEC;
+ int delay_us = __8b10b_channel_eq_delay_us(aux, rd_interval);

- usleep_range(rd_interval, rd_interval * 2);
+ usleep_range(delay_us, delay_us * 2);
}

void drm_dp_link_train_channel_eq_delay(const struct drm_dp_aux *aux,
--
2.30.2