diff options
| author | Kuogee Hsieh <khsieh@codeaurora.org> | 2020-11-03 12:49:01 -0800 |
|---|---|---|
| committer | Rob Clark <robdclark@chromium.org> | 2020-11-10 12:39:48 -0800 |
| commit | ea530388e64bd584645f2d89e40ca7dffade8eff (patch) | |
| tree | 02f229b34f4be0b7c5448b7ccd22d8ff489343f4 /drivers/gpu/drm/msm/dp/dp_ctrl.c | |
| parent | 231a04fcc6cb5b0e5f72c015d36462a17355f925 (diff) | |
drm/msm/dp: skip checking LINK_STATUS_UPDATED bit
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>
Diffstat (limited to 'drivers/gpu/drm/msm/dp/dp_ctrl.c')
| -rw-r--r-- | drivers/gpu/drm/msm/dp/dp_ctrl.c | 20 |
1 files changed, 6 insertions, 14 deletions
diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c index 139af85a8f2d..c569e97c82a6 100644 --- a/drivers/gpu/drm/msm/dp/dp_ctrl.c +++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c @@ -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; - - 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 = -EINVAL; } - return -ETIMEDOUT; + return ret; } static int dp_ctrl_link_train_1(struct dp_ctrl_private *ctrl, |