Bug 112084

Summary: VGA external monitor not working after update to 5.3.x linux
Product: DRI Reporter: Andrija <akijo97>
Component: DRM/IntelAssignee: Intel GFX Bugs mailing list <intel-gfx-bugs>
Status: RESOLVED FIXED QA Contact: Intel GFX Bugs mailing list <intel-gfx-bugs>
Severity: critical    
Priority: high CC: intel-gfx-bugs, jani.nikula
Version: unspecified   
Hardware: x86-64 (AMD64)   
OS: Linux (All)   
Whiteboard: Triaged, ReadyForDev
i915 platform: HSW i915 features: display/Other
Attachments:
Description Flags
journalctl -b (boot log, drm.debug=0x1e log_buf_len=1)
none
[PATCH] drm/i915: Fix PCH reference clock for FDI on HSW/BDW none

Description Andrija 2019-10-21 22:36:35 UTC 
Created attachment 145788 [details]
journalctl -b (boot log,  drm.debug=0x1e log_buf_len=1)

OS: Arch linux
kernel: 5.3.7

After update to 5.3.x kernel external monitor on VGA port not working


[drm:hsw_fdi_link_train [i915]] *ERROR* FDI link training failed!
[drm:intel_set_pch_fifo_underrun_reporting [i915]] *ERROR* uncleared pch fifo underrun on pch transcoder A
[drm:cpt_irq_handler [i915]] *ERROR* PCH transcoder A FIFO underrun


https://bbs.archlinux.org/viewtopic.php?id=249764

Arch linux thread
Comment 1 Andrija 2019-10-21 22:43:44 UTC 
hardware:

thinkpad t440p
i5-4200m
hd4600
Comment 2 Ville Syrjala 2019-10-22 10:20:54 UTC 
Created attachment 145792 [details] [review]
[PATCH] drm/i915: Fix PCH reference clock for FDI on HSW/BDW

Please test whether this fixes it.
Comment 3 Andrija 2019-10-22 17:37:12 UTC 
Yes, that's it. This fixed problem.
Comment 4 Ville Syrjala 2019-10-22 18:43:42 UTC 
(In reply to Andrija from comment #3)
> Yes, that's it. This fixed problem.

Cool. Keeping the bug open until the fix lands in our tree.
Comment 5 Ville Syrjala 2019-10-25 17:24:22 UTC 
Now landed.

commit dd5279c71405533d4ddbb9453effc60f0f5bf211
Author: Ville Syrjälä <ville.syrjala@linux.intel.com>
Date:   Tue Oct 22 21:56:43 2019 +0300

    drm/i915: Fix PCH reference clock for FDI on HSW/BDW

Thanks for the bug report and testing.
Comment 6 Andrija 2019-11-01 16:07:46 UTC 
Do you know in which linux version this patch will be apllied?
Comment 7 Lakshmi 2019-11-05 13:38:50 UTC 
(In reply to Andrija from comment #6)
> Do you know in which linux version this patch will be apllied?

Drm-tip (https://cgit.freedesktop.org/drm-tip) will have the latest changes.
Comment 8 Jani Saarinen 2019-11-05 15:25:32 UTC 
Jani, we are now at 5.4rc6 so I suppose we missed 5.5 and goes to 5.6? Or how this goes?

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