[PATCH 01/22] drm/i915: Don't pass *DP around to link training functions

Ander Conselvan de Oliveira
2015-10-23T10:02:11Z

It just makes the code more confusing, so just reference intel_dp_>DP
directly.

Note that this also fix a bug where the value of intel_dp->DP could be
different than the last value written to the hw, due to an early return
that would skip the 'intel_dp->DP = DP' line.

v2: Don't preserve old DP value on failure. (Sivakumar)
- Don't call drm_dp_clock_recovery_ok() twice. (Sivakumar)
- Keep return type of clock recovery and channel equalization
functions as void. (Ander)

v3: Remove DP parameter from intel_dp_set_signal_levels(). (Sivakumar)

Signed-off-by: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
---
drivers/gpu/drm/i915/intel_dp.c | 47 ++++++++++++++++++-----------------------
1 file changed, 20 insertions(+), 27 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 8287df4..648300e 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -3552,7 +3552,7 @@ gen7_edp_signal_levels(uint8_t train_set)

/* Properly updates "DP" with the correct signal levels. */
static void
-intel_dp_set_signal_levels(struct intel_dp *intel_dp, uint32_t *DP)
+intel_dp_set_signal_levels(struct intel_dp *intel_dp)
{
struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
enum port port = intel_dig_port->port;
@@ -3591,12 +3591,11 @@ intel_dp_set_signal_levels(struct intel_dp *intel_dp, uint32_t *DP)
(train_set & DP_TRAIN_PRE_EMPHASIS_MASK) >>
DP_TRAIN_PRE_EMPHASIS_SHIFT);

- *DP = (*DP & ~mask) | signal_levels;
+ intel_dp->DP = (intel_dp->DP & ~mask) | signal_levels;
}

static bool
intel_dp_set_link_train(struct intel_dp *intel_dp,
- uint32_t *DP,
uint8_t dp_train_pat)
{
struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
@@ -3605,9 +3604,9 @@ intel_dp_set_link_train(struct intel_dp *intel_dp,
uint8_t buf[sizeof(intel_dp->train_set) + 1];
int ret, len;

- _intel_dp_set_link_train(intel_dp, DP, dp_train_pat);
+ _intel_dp_set_link_train(intel_dp, &intel_dp->DP, dp_train_pat);

- I915_WRITE(intel_dp->output_reg, *DP);
+ I915_WRITE(intel_dp->output_reg, intel_dp->DP);
POSTING_READ(intel_dp->output_reg);

buf[0] = dp_train_pat;
@@ -3628,17 +3627,17 @@ intel_dp_set_link_train(struct intel_dp *intel_dp,
}

static bool
-intel_dp_reset_link_train(struct intel_dp *intel_dp, uint32_t *DP,
+intel_dp_reset_link_train(struct intel_dp *intel_dp,
uint8_t dp_train_pat)
{
if (!intel_dp->train_set_valid)
memset(intel_dp->train_set, 0, sizeof(intel_dp->train_set));
- intel_dp_set_signal_levels(intel_dp, DP);
- return intel_dp_set_link_train(intel_dp, DP, dp_train_pat);
+ intel_dp_set_signal_levels(intel_dp);
+ return intel_dp_set_link_train(intel_dp, dp_train_pat);
}

static bool
-intel_dp_update_link_train(struct intel_dp *intel_dp, uint32_t *DP,
+intel_dp_update_link_train(struct intel_dp *intel_dp,
const uint8_t link_status[DP_LINK_STATUS_SIZE])
{
struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
@@ -3647,9 +3646,9 @@ intel_dp_update_link_train(struct intel_dp *intel_dp, uint32_t *DP,
int ret;

intel_get_adjust_train(intel_dp, link_status);
- intel_dp_set_signal_levels(intel_dp, DP);
+ intel_dp_set_signal_levels(intel_dp);

- I915_WRITE(intel_dp->output_reg, *DP);
+ I915_WRITE(intel_dp->output_reg, intel_dp->DP);
POSTING_READ(intel_dp->output_reg);

ret = drm_dp_dpcd_write(&intel_dp->aux, DP_TRAINING_LANE0_SET,
@@ -3698,7 +3697,6 @@ intel_dp_link_training_clock_recovery(struct intel_dp *intel_dp)
int i;
uint8_t voltage;
int voltage_tries, loop_tries;
- uint32_t DP = intel_dp->DP;
uint8_t link_config[2];
uint8_t link_bw, rate_select;

@@ -3722,10 +3720,10 @@ intel_dp_link_training_clock_recovery(struct intel_dp *intel_dp)
link_config[1] = DP_SET_ANSI_8B10B;
drm_dp_dpcd_write(&intel_dp->aux, DP_DOWNSPREAD_CTRL, link_config, 2);

- DP |= DP_PORT_EN;
+ intel_dp->DP |= DP_PORT_EN;

/* clock recovery */
- if (!intel_dp_reset_link_train(intel_dp, &DP,
+ if (!intel_dp_reset_link_train(intel_dp,
DP_TRAINING_PATTERN_1 |
DP_LINK_SCRAMBLING_DISABLE)) {
DRM_ERROR("failed to enable link training\n");
@@ -3757,7 +3755,7 @@ intel_dp_link_training_clock_recovery(struct intel_dp *intel_dp)
DRM_DEBUG_KMS("clock recovery not ok, reset");
/* clear the flag as we are not reusing train set */
intel_dp->train_set_valid = false;
- if (!intel_dp_reset_link_train(intel_dp, &DP,
+ if (!intel_dp_reset_link_train(intel_dp,
DP_TRAINING_PATTERN_1 |
DP_LINK_SCRAMBLING_DISABLE)) {
DRM_ERROR("failed to enable link training\n");
@@ -3776,7 +3774,7 @@ intel_dp_link_training_clock_recovery(struct intel_dp *intel_dp)
DRM_ERROR("too many full retries, give up\n");
break;
}
- intel_dp_reset_link_train(intel_dp, &DP,
+ intel_dp_reset_link_train(intel_dp,
DP_TRAINING_PATTERN_1 |
DP_LINK_SCRAMBLING_DISABLE);
voltage_tries = 0;
@@ -3795,13 +3793,11 @@ intel_dp_link_training_clock_recovery(struct intel_dp *intel_dp)
voltage = intel_dp->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK;

/* Update training set as requested by target */
- if (!intel_dp_update_link_train(intel_dp, &DP, link_status)) {
+ if (!intel_dp_update_link_train(intel_dp, link_status)) {
DRM_ERROR("failed to update link training\n");
break;
}
}
-
- intel_dp->DP = DP;
}

static void
@@ -3811,7 +3807,6 @@ intel_dp_link_training_channel_equalization(struct intel_dp *intel_dp)
struct drm_device *dev = dig_port->base.base.dev;
bool channel_eq = false;
int tries, cr_tries;
- uint32_t DP = intel_dp->DP;
uint32_t training_pattern = DP_TRAINING_PATTERN_2;

/*
@@ -3830,7 +3825,7 @@ intel_dp_link_training_channel_equalization(struct intel_dp *intel_dp)
DRM_ERROR("5.4 Gbps link rate without HBR2/TPS3 support\n");

/* channel equalization */
- if (!intel_dp_set_link_train(intel_dp, &DP,
+ if (!intel_dp_set_link_train(intel_dp,
training_pattern |
DP_LINK_SCRAMBLING_DISABLE)) {
DRM_ERROR("failed to start channel equalization\n");
@@ -3859,7 +3854,7 @@ intel_dp_link_training_channel_equalization(struct intel_dp *intel_dp)
intel_dp->lane_count)) {
intel_dp->train_set_valid = false;
intel_dp_link_training_clock_recovery(intel_dp);
- intel_dp_set_link_train(intel_dp, &DP,
+ intel_dp_set_link_train(intel_dp,
training_pattern |
DP_LINK_SCRAMBLING_DISABLE);
cr_tries++;
@@ -3876,7 +3871,7 @@ intel_dp_link_training_channel_equalization(struct intel_dp *intel_dp)
if (tries > 5) {
intel_dp->train_set_valid = false;
intel_dp_link_training_clock_recovery(intel_dp);
- intel_dp_set_link_train(intel_dp, &DP,
+ intel_dp_set_link_train(intel_dp,
training_pattern |
DP_LINK_SCRAMBLING_DISABLE);
tries = 0;
@@ -3885,7 +3880,7 @@ intel_dp_link_training_channel_equalization(struct intel_dp *intel_dp)
}

/* Update training set as requested by target */
- if (!intel_dp_update_link_train(intel_dp, &DP, link_status)) {
+ if (!intel_dp_update_link_train(intel_dp, link_status)) {
DRM_ERROR("failed to update link training\n");
break;
}
@@ -3894,8 +3889,6 @@ intel_dp_link_training_channel_equalization(struct intel_dp *intel_dp)

intel_dp_set_idle_link_train(intel_dp);

- intel_dp->DP = DP;
-
if (channel_eq) {
intel_dp->train_set_valid = true;
DRM_DEBUG_KMS("Channel EQ done. DP Training successful\n");
@@ -3904,7 +3897,7 @@ intel_dp_link_training_channel_equalization(struct intel_dp *intel_dp)

void intel_dp_stop_link_train(struct intel_dp *intel_dp)
{
- intel_dp_set_link_train(intel_dp, &intel_dp->DP,
+ intel_dp_set_link_train(intel_dp,
DP_TRAINING_PATTERN_DISABLE);