[PATCH] drm/msm/dp: skip checking LINK_STATUS_UPDATED bit

From: Kuogee Hsieh
Date: Tue Oct 20 2020 - 13:00:32 EST


No need to check LINK_STATuS_UPDATED bit before
return 6 bytes of link status during link training.
This patch also fix phy compliance test link rate
conversion error.

Signed-off-by: Kuogee Hsieh <khsieh@xxxxxxxxxxxxxx>
---
drivers/gpu/drm/msm/dp/dp_ctrl.c | 20 ++++++--------------
drivers/gpu/drm/msm/dp/dp_link.c | 24 +++++++++++-------------
2 files changed, 17 insertions(+), 27 deletions(-)

diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c
index 6bdaec778c4c..76e891c91c6e 100644
--- a/drivers/gpu/drm/msm/dp/dp_ctrl.c
+++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c
@@ -1061,23 +1061,15 @@ static bool dp_ctrl_train_pattern_set(struct dp_ctrl_private *ctrl,
static int dp_ctrl_read_link_status(struct dp_ctrl_private *ctrl,
u8 *link_status)
{
- int len = 0;
- u32 const offset = DP_LANE_ALIGN_STATUS_UPDATED - DP_LANE0_1_STATUS;
- u32 link_status_read_max_retries = 100;
-
- while (--link_status_read_max_retries) {
- len = drm_dp_dpcd_read_link_status(ctrl->aux,
- link_status);
- if (len != DP_LINK_STATUS_SIZE) {
- DRM_ERROR("DP link status read failed, err: %d\n", len);
- return len;
- }
+ int ret = 0, len;

- if (!(link_status[offset] & DP_LINK_STATUS_UPDATED))
- return 0;
+ len = drm_dp_dpcd_read_link_status(ctrl->aux, link_status);
+ if (len != DP_LINK_STATUS_SIZE) {
+ DRM_ERROR("DP link status read failed, err: %d\n", len);
+ ret = len;
}

- return -ETIMEDOUT;
+ return ret;
}

static int dp_ctrl_link_train_1(struct dp_ctrl_private *ctrl,
diff --git a/drivers/gpu/drm/msm/dp/dp_link.c b/drivers/gpu/drm/msm/dp/dp_link.c
index c811da515fb3..58d65daae3b3 100644
--- a/drivers/gpu/drm/msm/dp/dp_link.c
+++ b/drivers/gpu/drm/msm/dp/dp_link.c
@@ -773,7 +773,8 @@ static int dp_link_process_link_training_request(struct dp_link_private *link)
link->request.test_lane_count);

link->dp_link.link_params.num_lanes = link->request.test_lane_count;
- link->dp_link.link_params.rate = link->request.test_link_rate;
+ link->dp_link.link_params.rate =
+ drm_dp_bw_code_to_link_rate(link->request.test_link_rate);

return 0;
}
@@ -939,20 +940,17 @@ static u8 get_link_status(const u8 link_status[DP_LINK_STATUS_SIZE], int r)
*/
static int dp_link_process_link_status_update(struct dp_link_private *link)
{
- if (!(get_link_status(link->link_status,
- DP_LANE_ALIGN_STATUS_UPDATED) &
- DP_LINK_STATUS_UPDATED) ||
- (drm_dp_clock_recovery_ok(link->link_status,
- link->dp_link.link_params.num_lanes) &&
- drm_dp_channel_eq_ok(link->link_status,
- link->dp_link.link_params.num_lanes)))
- return -EINVAL;
+ bool channel_eq_done = drm_dp_channel_eq_ok(link->link_status,
+ link->dp_link.link_params.num_lanes);
+
+ bool clock_recovery_done = drm_dp_clock_recovery_ok(link->link_status,
+ link->dp_link.link_params.num_lanes);

DRM_DEBUG_DP("channel_eq_done = %d, clock_recovery_done = %d\n",
- drm_dp_clock_recovery_ok(link->link_status,
- link->dp_link.link_params.num_lanes),
- drm_dp_clock_recovery_ok(link->link_status,
- link->dp_link.link_params.num_lanes));
+ channel_eq_done, clock_recovery_done);
+
+ if (channel_eq_done && clock_recovery_done)
+ return -EINVAL;

return 0;
}

base-commit: 0855cb4b31953b8c539e57b970da8146bcd4405a
--
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