[PATCH v2 2/3] drm/dp_helper: Define options for FRL training for HDMI2.1 PCON

Ankit Nautiyal ankit.k.nautiyal at intel.com
Thu Feb 11 06:43:04 UTC 2021


Currently the FRL training mode (Concurrent, Sequential) and
training type (Normal, Extended) are not defined properly and
are passed as bool values in drm_helpers for pcon
configuration for FRL training.

This patch:
-Add register masks for Sequential and Normal FRL training options.
-Fixes the drm_helpers for FRL Training configuration to use the
 appropriate masks.
-Modifies the calls to the above drm_helpers in i915/intel_dp as per
 the above change.

v2: Re-used the register masks for these options, instead of enum. (Ville)

Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal at intel.com>
---
 drivers/gpu/drm/drm_dp_helper.c         | 24 ++++++++++++++----------
 drivers/gpu/drm/i915/display/intel_dp.c | 10 ++++------
 include/drm/drm_dp_helper.h             |  6 ++++--
 3 files changed, 22 insertions(+), 18 deletions(-)

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index eedbb48815b7..cb2f53e56685 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -2635,14 +2635,16 @@ EXPORT_SYMBOL(drm_dp_pcon_is_frl_ready);
  * drm_dp_pcon_frl_configure_1() - Set HDMI LINK Configuration-Step1
  * @aux: DisplayPort AUX channel
  * @max_frl_gbps: maximum frl bw to be configured between PCON and HDMI sink
- * @concurrent_mode: true if concurrent mode or operation is required,
- * false otherwise.
+ * @frl_mode: FRL Training mode, it can be either Concurrent or Sequential.
+ * In Concurrent Mode, the FRL link bring up can be done along with
+ * DP Link training. In Sequential mode, the FRL link bring up is done prior to
+ * the DP Link training.
  *
  * Returns 0 if success, else returns negative error code.
  */
 
 int drm_dp_pcon_frl_configure_1(struct drm_dp_aux *aux, int max_frl_gbps,
-				bool concurrent_mode)
+				u8 frl_mode)
 {
 	int ret;
 	u8 buf;
@@ -2651,7 +2653,7 @@ int drm_dp_pcon_frl_configure_1(struct drm_dp_aux *aux, int max_frl_gbps,
 	if (ret < 0)
 		return ret;
 
-	if (concurrent_mode)
+	if (frl_mode == DP_PCON_ENABLE_CONCURRENT_LINK)
 		buf |= DP_PCON_ENABLE_CONCURRENT_LINK;
 	else
 		buf &= ~DP_PCON_ENABLE_CONCURRENT_LINK;
@@ -2694,21 +2696,23 @@ EXPORT_SYMBOL(drm_dp_pcon_frl_configure_1);
  * drm_dp_pcon_frl_configure_2() - Set HDMI Link configuration Step-2
  * @aux: DisplayPort AUX channel
  * @max_frl_mask : Max FRL BW to be tried by the PCON with HDMI Sink
- * @extended_train_mode : true for Extended Mode, false for Normal Mode.
- * In Normal mode, the PCON tries each frl bw from the max_frl_mask starting
- * from min, and stops when link training is successful. In Extended mode, all
- * frl bw selected in the mask are trained by the PCON.
+ * @frl_type : FRL training type, can be Extended, or Normal.
+ * In Normal FRL training, the PCON tries each frl bw from the max_frl_mask
+ * starting from min, and stops when link training is successful. In Extended
+ * FRL training, all frl bw selected in the mask are trained by the PCON.
  *
  * Returns 0 if success, else returns negative error code.
  */
 int drm_dp_pcon_frl_configure_2(struct drm_dp_aux *aux, int max_frl_mask,
-				bool extended_train_mode)
+				u8 frl_type)
 {
 	int ret;
 	u8 buf = max_frl_mask;
 
-	if (extended_train_mode)
+	if (frl_type == DP_PCON_FRL_LINK_TRAIN_EXTENDED)
 		buf |= DP_PCON_FRL_LINK_TRAIN_EXTENDED;
+	else
+		buf &= ~DP_PCON_FRL_LINK_TRAIN_EXTENDED;
 
 	ret = drm_dp_dpcd_writeb(aux, DP_PCON_HDMI_LINK_CONFIG_2, buf);
 	if (ret < 0)
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 61beeb3161e2..510c6b442c1b 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -2559,10 +2559,6 @@ static int intel_dp_hdmi_sink_max_frl(struct intel_dp *intel_dp)
 
 static int intel_dp_pcon_start_frl_training(struct intel_dp *intel_dp)
 {
-#define PCON_EXTENDED_TRAIN_MODE (1 > 0)
-#define PCON_CONCURRENT_MODE (1 > 0)
-#define PCON_SEQUENTIAL_MODE !PCON_CONCURRENT_MODE
-#define PCON_NORMAL_TRAIN_MODE !PCON_EXTENDED_TRAIN_MODE
 #define TIMEOUT_FRL_READY_MS 500
 #define TIMEOUT_HDMI_LINK_ACTIVE_MS 1000
 
@@ -2596,10 +2592,12 @@ static int intel_dp_pcon_start_frl_training(struct intel_dp *intel_dp)
 		return -ETIMEDOUT;
 
 	max_frl_bw_mask = intel_dp_pcon_set_frl_mask(max_frl_bw);
-	ret = drm_dp_pcon_frl_configure_1(&intel_dp->aux, max_frl_bw, PCON_SEQUENTIAL_MODE);
+	ret = drm_dp_pcon_frl_configure_1(&intel_dp->aux, max_frl_bw,
+					  DP_PCON_ENABLE_SEQUENTIAL_LINK);
 	if (ret < 0)
 		return ret;
-	ret = drm_dp_pcon_frl_configure_2(&intel_dp->aux, max_frl_bw_mask, PCON_NORMAL_TRAIN_MODE);
+	ret = drm_dp_pcon_frl_configure_2(&intel_dp->aux, max_frl_bw_mask,
+					  DP_PCON_FRL_LINK_TRAIN_NORMAL);
 	if (ret < 0)
 		return ret;
 	ret = drm_dp_pcon_frl_enable(&intel_dp->aux);
diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index edffd1dcca3e..f1c7e09728d4 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -1171,6 +1171,7 @@ struct drm_device;
 # define DP_PCON_ENABLE_MAX_BW_48GBPS	       6
 # define DP_PCON_ENABLE_SOURCE_CTL_MODE       (1 << 3)
 # define DP_PCON_ENABLE_CONCURRENT_LINK       (1 << 4)
+# define DP_PCON_ENABLE_SEQUENTIAL_LINK       (0 << 4)
 # define DP_PCON_ENABLE_LINK_FRL_MODE         (1 << 5)
 # define DP_PCON_ENABLE_HPD_READY	      (1 << 6)
 # define DP_PCON_ENABLE_HDMI_LINK             (1 << 7)
@@ -1185,6 +1186,7 @@ struct drm_device;
 # define DP_PCON_FRL_BW_MASK_40GBPS           (1 << 4)
 # define DP_PCON_FRL_BW_MASK_48GBPS           (1 << 5)
 # define DP_PCON_FRL_LINK_TRAIN_EXTENDED      (1 << 6)
+# define DP_PCON_FRL_LINK_TRAIN_NORMAL        (0 << 6)
 
 /* PCON HDMI LINK STATUS */
 #define DP_PCON_HDMI_TX_LINK_STATUS           0x303B
@@ -2149,9 +2151,9 @@ int drm_dp_get_pcon_max_frl_bw(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
 int drm_dp_pcon_frl_prepare(struct drm_dp_aux *aux, bool enable_frl_ready_hpd);
 bool drm_dp_pcon_is_frl_ready(struct drm_dp_aux *aux);
 int drm_dp_pcon_frl_configure_1(struct drm_dp_aux *aux, int max_frl_gbps,
-				bool concurrent_mode);
+				u8 frl_mode);
 int drm_dp_pcon_frl_configure_2(struct drm_dp_aux *aux, int max_frl_mask,
-				bool extended_train_mode);
+				u8 frl_type);
 int drm_dp_pcon_reset_frl_config(struct drm_dp_aux *aux);
 int drm_dp_pcon_frl_enable(struct drm_dp_aux *aux);
 
-- 
2.29.2



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