From b52c7c7704f2f5c2611b633fe052ba74c25d7de1 Mon Sep 17 00:00:00 2001
From: Jani Nikula <jani.nikula@intel.com>
Date: Thu, 14 Oct 2021 18:00:58 +0300
Subject: drm/dp: reuse the 8b/10b link training delay helpers
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Git-commit: 02ed47aa6cc697fc34053c011fe72984a86273cb
Patch-mainline: v5.17-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225

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.

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211014150059.28957-2-jani.nikula@intel.com
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 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,
-- 
2.38.1