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disp: msm: dp: add 1.4a cts support for link training

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Add support for new requirements in 1.4a CTS which need
to try link training 1 on different lane counts and link
rates.

CRs-Fixed: 2458753
Change-Id: I2039822f420a73232df7293afcddd7bee263c7b4
Signed-off-by: Ajay Singh Parmar <aparmar@codeaurora.org>
This commit is contained in:
Ajay Singh Parmar
2019-05-17 15:33:22 -07:00
parent 91b9fb1222
commit aa11061eed
1 changed files with 37 additions and 5 deletions
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42
msm/dp/dp_ctrl.c
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@@ -74,6 +74,7 @@ struct dp_ctrl_private {
atomic_t aborted; atomic_t aborted;
u8 initial_lane_count; u8 initial_lane_count;
u8 initial_bw_code;
u32 vic; u32 vic;
u32 stream_count; u32 stream_count;
@@ -295,6 +296,26 @@ static int dp_ctrl_lane_count_down_shift(struct dp_ctrl_private *ctrl)
return ret; return ret;
} }
static bool dp_ctrl_is_link_rate_rbr(struct dp_ctrl_private *ctrl)
{
return ctrl->link->link_params.bw_code == DP_LINK_BW_1_62;
}
static u8 dp_ctrl_get_active_lanes(struct dp_ctrl_private *ctrl,
u8 *link_status)
{
u8 lane, count = 0;
for (lane = 0; lane < ctrl->link->link_params.lane_count; lane++) {
if (link_status[lane / 2] & (1 << (lane * 4)))
count++;
else
break;
}
return count;
}
static int dp_ctrl_link_training_1(struct dp_ctrl_private *ctrl) static int dp_ctrl_link_training_1(struct dp_ctrl_private *ctrl)
{ {
int tries, old_v_level, ret = -EINVAL; int tries, old_v_level, ret = -EINVAL;
@@ -343,15 +364,13 @@ static int dp_ctrl_link_training_1(struct dp_ctrl_private *ctrl)
else else
break; break;
if (ctrl->link->phy_params.v_level == DP_LINK_VOLTAGE_MAX) { if (ctrl->link->phy_params.v_level == DP_LINK_VOLTAGE_MAX) {
pr_err_ratelimited("max v_level reached\n"); pr_err_ratelimited("max v_level reached\n");
break; break;
} }
if (old_v_level == ctrl->link->phy_params.v_level) { if (old_v_level == ctrl->link->phy_params.v_level) {
tries++; if (++tries >= maximum_retries) {
if (tries >= maximum_retries) {
pr_err("max tries reached\n"); pr_err("max tries reached\n");
ret = -ETIMEDOUT; ret = -ETIMEDOUT;
break; break;
@@ -366,6 +385,18 @@ static int dp_ctrl_link_training_1(struct dp_ctrl_private *ctrl)
ctrl->link->adjust_levels(ctrl->link, link_status); ctrl->link->adjust_levels(ctrl->link, link_status);
} }
if (ret && dp_ctrl_is_link_rate_rbr(ctrl)) {
u8 active_lanes = dp_ctrl_get_active_lanes(ctrl, link_status);
if (active_lanes) {
ctrl->link->link_params.lane_count = active_lanes;
ctrl->link->link_params.bw_code = ctrl->initial_bw_code;
/* retry with new settings */
ret = -EAGAIN;
}
}
ctrl->aux->state &= ~DP_STATE_TRAIN_1_STARTED; ctrl->aux->state &= ~DP_STATE_TRAIN_1_STARTED;
if (ret) if (ret)
@@ -467,7 +498,7 @@ static int dp_ctrl_link_training_2(struct dp_ctrl_private *ctrl)
else else
break; break;
if (tries > maximum_retries) { if (tries >= maximum_retries) {
ret = dp_ctrl_lane_count_down_shift(ctrl); ret = dp_ctrl_lane_count_down_shift(ctrl);
break; break;
} }
@@ -1227,8 +1258,9 @@ static int dp_ctrl_on(struct dp_ctrl *dp_ctrl, bool mst_mode,
ctrl->link->link_params.bw_code, ctrl->link->link_params.bw_code,
ctrl->link->link_params.lane_count); ctrl->link->link_params.lane_count);
/* backup initial lane count */ /* backup initial lane count and bw code */
ctrl->initial_lane_count = ctrl->link->link_params.lane_count; ctrl->initial_lane_count = ctrl->link->link_params.lane_count;
ctrl->initial_bw_code = ctrl->link->link_params.bw_code;
rc = dp_ctrl_link_setup(ctrl, shallow); rc = dp_ctrl_link_setup(ctrl, shallow);
ctrl->power_on = true; ctrl->power_on = true;