iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

drm/msm/dp: skip checking LINK_STATUS_UPDATED bit

Browse Source 
Some dongle will not clear LINK_STATUS_UPDATED bit after
DPCD read which cause link training failed. This patch
just read 6 bytes of DPCD link status from sink and return
without checking LINK_STATUS_UPDATED bit.
Only 8 bits are used to represent link rate at sinker DPCD.
The really link rate is 2.7Mb times the 8 bits value.
For example, 0x0A at DPCD is equal to 2.7Gb (10 * 2.7Mb).
This patch also convert 8 bits value of DPCD to really link
rate to fix worng link rate error during phy compliance test.

Fixes: 6625e2637d93 ("drm/msm/dp: DisplayPort PHY compliance tests fixup")
Signed-off-by: Kuogee Hsieh <khsieh@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>
This commit is contained in:
Kuogee Hsieh 2020-11-03 12:49:01 -08:00 committed by Rob Clark
parent 231a04fcc6
commit ea530388e6
2 changed files with 20 additions and 29 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
drivers/gpu/drm/msm/dp/dp_ctrl.c
View File

@ -1064,23 +1064,15 @@ 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;
int ret = 0, len;
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;
}
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 = -EINVAL;
}
return -ETIMEDOUT;
return ret;
}
static int dp_ctrl_link_train_1(struct dp_ctrl_private *ctrl,

29
drivers/gpu/drm/msm/dp/dp_link.c
View File

@ -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;
}
@ -943,22 +944,20 @@ 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);
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));
bool clock_recovery_done = drm_dp_clock_recovery_ok(link->link_status,
link->dp_link.link_params.num_lanes);
return 0;
DRM_DEBUG_DP("channel_eq_done = %d, clock_recovery_done = %d\n",
channel_eq_done, clock_recovery_done);
if (channel_eq_done && clock_recovery_done)
return -EINVAL;
return 0;
}
/**