Refer to DP link CTS 1.2/1.4 spec, the following test case request
source read DPCD 200h - 205h to get latest link status from sink.
(4.3.2.4) Handling of IRQ HPD Pulse with No Error Status Bits Set
(400.3.2.1) Successful Link Re-training After IRQ HPD Pulse
Due to Loss of Symbol Lock: HBR2 Extension
(400.3.2.2) Successful Link Re-training After IRQ HPD Pulse Due
to Loss of Clock Recovery Lock: HBR2 Extension
(400.3.2.3) Successful Link Re-training After IRQ HPD Pulse Due
to Loss of Inter-lane Alignment Lock: HBR2 Extension
So far, DRM DP driver just read back the link status from 202h
to 207h. DPR-120 would judge source can't pass these cases and
shows below error messages.
"Test FAILED, Source DUT does not read DPCD registers 200h-205h
within 100 ms".
v2: Use sizeof() to retrieve array size.
Cc: Jani Nikula <jani.nikula@xxxxxxxxx>
Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Cc: Lyude Paul <lyude@xxxxxxxxxx>
Cc: Simon Ser <contact@xxxxxxxxxxx>
Cc: Cooper Chiou <cooper.chiou@xxxxxxxxx>
Cc: William Tseng <william.tseng@xxxxxxxxx>
Signed-off-by: Lee Shawn C <shawn.c.lee@xxxxxxxxx>
---
drivers/gpu/drm/drm_dp_helper.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 24bbc710c825..4f03df317d62 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -410,17 +410,19 @@ int drm_dp_dpcd_read_phy_link_status(struct drm_dp_aux *aux,
u8 link_status[DP_LINK_STATUS_SIZE])
{
int ret;
+ u8 full_link_stat[DP_LINK_STATUS_SIZE + 2];
if (dp_phy == DP_PHY_DPRX) {
ret = drm_dp_dpcd_read(aux,
- DP_LANE0_1_STATUS,
- link_status,
- DP_LINK_STATUS_SIZE);
+ DP_SINK_COUNT,
+ full_link_stat,
+ sizeof(full_link_stat));
if (ret < 0)
return ret;
- WARN_ON(ret != DP_LINK_STATUS_SIZE);
+ memcpy(link_status, full_link_stat + 2, DP_LINK_STATUS_SIZE);
+ WARN_ON(ret != DP_LINK_STATUS_SIZE + 2);
return 0;
}
--
2.17.1
