Bug 109112 - "*ERROR* Failed to probe lspcon" when HDMI isn't plugged before boot
Summary: "*ERROR* Failed to probe lspcon" when HDMI isn't plugged before boot
Status: NEEDINFO
Alias: None
Product: DRI
Classification: Unclassified
Component: DRM/Intel (show other bugs)
Version: XOrg git
Hardware: Other All
: medium normal
Assignee: Swati Sharma
QA Contact: Intel GFX Bugs mailing list
URL:
Whiteboard: Triaged
Keywords:
Depends on:
Blocks:
 
Reported: 2018-12-20 07:25 UTC by Kai-Heng Feng
Modified: 2019-02-20 11:21 UTC (History)
3 users (show)

See Also:
i915 platform: CFL
i915 features: display/LSPCON


Attachments
HDMI cable plugged before boot, LSPCON works (157.15 KB, text/plain)
2018-12-20 07:26 UTC, Kai-Heng Feng
no flags Details
HDMI cable _not_ plugged before boot, LSPCON doesn't work (126.18 KB, text/plain)
2018-12-20 07:27 UTC, Kai-Heng Feng
no flags Details
i915_display_info, HDMI cable plugged before boot (5.63 KB, text/plain)
2019-01-04 03:54 UTC, Kai-Heng Feng
no flags Details
i915_display_info, HDMI cable plugged after boot (579 bytes, text/plain)
2019-01-04 03:54 UTC, Kai-Heng Feng
no flags Details
VBT info (6.00 KB, application/octet-stream)
2019-01-04 03:55 UTC, Kai-Heng Feng
no flags Details

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Description Kai-Heng Feng 2018-12-20 07:25:58 UTC
Kernel vision: drm-intel-nightly, cod/tip/drm-tip/2018-12-19.

When booting the system without HDMI cable plugged, the system can never detect HDMI cable afterward.

This issue is not observed when HDMI cable is plugged before boot, LSPCON gets probed successfully in this case. HDMI hotplug also works in this case.

I tried to increase both retry count and sleep time in lspcon_probe(), but it doesn't make any difference.
Comment 1 Kai-Heng Feng 2018-12-20 07:26:59 UTC
Created attachment 142857 [details]
HDMI cable plugged before boot, LSPCON works
Comment 2 Kai-Heng Feng 2018-12-20 07:27:38 UTC
Created attachment 142858 [details]
HDMI cable _not_ plugged before boot, LSPCON doesn't work
Comment 3 Kai-Heng Feng 2018-12-20 07:29:53 UTC
I also tested Windows 10. HDMI still works when the cable wasn't plugged before boot.
Comment 4 Lakshmi 2018-12-20 20:10:53 UTC
Swati, any comments here?
Comment 5 Swati Sharma 2018-12-21 13:14:09 UTC
Hi Kai-Heng-Feng,

To re-create same test scenario can be please elaborate how you are testing?
   1. Booting with which connector attached (if not HDMI)?
   2. After booting, are you doing hot-unplug of previous connector attached and 
      hot-plug of HDMI connector?
   3. After hot-plug of HDMI cable, are you seeing any blank screen/no signal?
   4. Are you executing any test?
Comment 6 Hugh Chao 2018-12-25 03:46:35 UTC
Hi, Swati,

1. No any connector attached.
2. If HDMI cable is plugged before boot, it will always have signal no matter how you hot-unplug and hot-plug HDMI.
3. If HDMI cable isn't connected before boot, It's always blank screen when we hot-plug the cable.
4. No, just normal boot up.
Comment 7 Swati Sharma 2018-12-26 12:06:55 UTC
Thanks Hugh Chao for the info. Seeing the logs where the LSP-Con works, LSP-Con chip being used is from Parade Tech. Can you please confirm whether you are seeing this issue in MCA LSP-Con chips as-well?
Comment 8 Kai-Heng Feng 2018-12-29 16:49:34 UTC
(In reply to Swati Sharma from comment #7)
> Thanks Hugh Chao for the info. Seeing the logs where the LSP-Con works,
> LSP-Con chip being used is from Parade Tech. Can you please confirm whether
> you are seeing this issue in MCA LSP-Con chips as-well?

Is LSPCON chip swappable? The platform in question is already on the market so I am not sure it's feasible to test different LSPCON chips.
Comment 9 Swati Sharma 2019-01-02 13:39:20 UTC
It's ok. There are 2 vendors of lspcon chip-Parade and MCA.
Can you please provide following info:
1. cat /sys/kernel/debug/dri/0/i915_display_info
2. attach /sys/kernel/debug/dri/0/i915_vbt
3. are you using any external dongle/cable?
Comment 10 Kai-Heng Feng 2019-01-04 03:54:19 UTC
Created attachment 142971 [details]
i915_display_info, HDMI cable plugged before boot
Comment 11 Kai-Heng Feng 2019-01-04 03:54:50 UTC
Created attachment 142972 [details]
i915_display_info, HDMI cable plugged after boot
Comment 12 Kai-Heng Feng 2019-01-04 03:55:05 UTC
Created attachment 142973 [details]
VBT info
Comment 13 Kai-Heng Feng 2019-01-04 03:56:30 UTC
(In reply to Swati Sharma from comment #9)
> 3. are you using any external dongle/cable?
Yes, it's a mini desktop so HDMI cable is required for this setup.
Comment 14 Anthony Wong 2019-01-14 02:32:04 UTC
Any update?
Comment 15 Swati Sharma 2019-01-14 09:17:01 UTC
Hi Wong,

I tried replicating issue locally on kabylake gen9 platform, however couldn't succeed. No lspcon probe issue is observed.

Configuration provided by you and mine is:
<Swati>
connector 83: type DP-1, status: connected
DP branch device present: yes
                Type: HDMI
                ID: 175IB0
                HW: 1.2
                SW: 8.41
                Max TMDS clock: 600000 kHz
                Max bpc: 12
<Kai-Heng Feng>
connector 109: type DP-3, status: connected
	DP branch device present: yes
		Type: HDMI
		ID: 175IB0
		HW: 1.0
		SW: 7.35
		Max TMDS clock: 600000 kHz
		Max bpc: 12
Here the difference is in HW and SW f/w. I will recommend you to please update to the latest sw f/w and test again.
Since Linux F/W Flash Tool is not ready yet to update the f/w, you can update f/w by booting with windows first and using their AuxUpdate tool.

In the logs of the failed case we can see "Native AUX CH down" and after that probe issue comes.
May be in the latest s/w f/w issue would have been resolved from the parade, if this needs a h/w update (which hopefully shouldn't be the case) then nothing can be done.

So, first update the s/w f/w, test and share your observation; only then we can take further steps.
Comment 16 Lakshmi 2019-02-13 11:26:18 UTC
Kai, have you verified the issue by updating fw? Any updates here?
Comment 17 Kai-Heng Feng 2019-02-20 11:11:45 UTC
(In reply to Lakshmi from comment #16)
> Kai, have you verified the issue by updating fw? Any updates here?

The system was sent to HP and I don't know the follow-up.
Maybe Hugh can answer your question...
Comment 18 Hugh Chao 2019-02-20 11:21:43 UTC
HP is still working on it, I'll feedback if I got any news


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