<7> [324.212725] [drm:drm_dp_dpcd_access] Too many retries, giving up. First error: -5
<3> [324.212863] [drm:intel_dp_start_link_train [i915]] *ERROR* failed to enable link training
<3> [349.753045] [drm:lspcon_init [i915]] *ERROR* Failed to probe lspcon
<3> [349.753168] [drm:intel_ddi_init [i915]] *ERROR* LSPCON init failed on port B
<3> [353.686349] [drm:lspcon_init [i915]] *ERROR* Failed to probe lspcon
<3> [353.686443] [drm:intel_ddi_init [i915]] *ERROR* LSPCON init failed on port B
This also got hit in the same way in https://intel-gfx-ci.01.org/tree/drm-tip/IGTPW_1981/issues.html
Also seen in https://patchwork.freedesktop.org/series/51215/ and https://patchwork.freedesktop.org/series/51258/
Please attach /sys/kernel/debug/dri/0/i915_vbt from the failing device.
Created attachment 142272 [details]
BIOS(VBT) information from failed machine.
Swati tested LSPCON probing on Bangalore APL system, where:
- LSPCON HW is on port B,
- VBT was bad, and was showing LSPCON on all ports A, B C
- On Port B, the probe was successful, but probe was failure on port
A and C (as there was no LSPCON)
- On FI-CI Build APL system:
- the VBT seems showing LSPCON only on Port B
- but we are seeing a failure during the probe itself, even on LSPCON port
So technically, Swati is not able to reproduce this issue yet (as the
probe failures were on non-LSPCON ports A and C, due to wrong VBT
Next steps for debug:
Lakshmi: Can you please share the BIOS(VBT) which is being flashed
on CI- APL system where the failure has been observed ?
Swati: Please flash this BIOS(VBT) on Bangalore APL system, and see
if you are able to reproduce this issue.
- If yes: Lets debug this issue further and root cause.
- If no: We might need to get access to CI-APL system, for root causing.
Created attachment 142273 [details]
BIOS VBT file
Adding KBL platform based on the latest results.
In the boot log of https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_5021/fi-apl-guc/boot0.log, it can be seen
<7>[ 6.938880] [drm:lspcon_wake_native_aux_ch [i915]] Native AUX CH up, DPCD version: 0.0
DPCD version is read incorrectly, after that lspcon probe error comes.
Failure of following i-g-t subtests has this thing common:
The same thing is happening for APL and KBL.
KBL NUC on which I am trying to reproduce this issue, DPCD version is read correctly and probe failure is not observed.