FS#45733 - [linux] external mini displayport-vga monitor not detected [drm:drm_dp_dpcd_access] too many retries
Attached to Project:
Arch Linux
Opened by Chris (kitteboss) - Tuesday, 21 July 2015, 16:55 GMT
Last edited by Allan McRae (Allan) - Saturday, 30 July 2016, 12:53 GMT
Opened by Chris (kitteboss) - Tuesday, 21 July 2015, 16:55 GMT
Last edited by Allan McRae (Allan) - Saturday, 30 July 2016, 12:53 GMT
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Details
Description:
Since linux kernel 4.1.x my external vga monitor, connected with a mini displayport to vga adapter is not detected anymore. xrandr says DP1 disconnected, even if connected and xrandr --output DP1 has no effect. Downgrading to linux 4.0.7 solves the issue, mini dispalyport to hdmi or dvi adapters are not affected. Hardware is a macbookpro8,1 with intel sandybridge Additional info: * package version(s) linux 4.1.x xf86-video-intel 1:2.99.917+381+g5772556-1 xorg-server 1.17.2-4 * config and/or log files etc. dmesg with drm.debug=14 as kernel parameter gives the following error [drm:drm_helper_probe_single_connector_modes_merge_bits] [CONNECTOR:40:DP-1] [drm:intel_dp_detect] [CONNECTOR:40:DP-1] [drm:drm_dp_dpcd_access] too many retries, giving up [drm:drm_dp_dpcd_access] too many retries, giving up [drm:drm_dp_dpcd_access] too many retries, giving up [drm:drm_dp_dpcd_access] too many retries, giving up https://bbs.archlinux.org/viewtopic.php?id=199540 Steps to reproduce: Update to linux 4.1.x and try to connect the vga monitor over the mini displayport |
This task depends upon
1d002fa720738bcd0bddb9178e9ea0773288e1dd is the first bad commit
commit 1d002fa720738bcd0bddb9178e9ea0773288e1dd
Author: Simon Farnsworth <simon.farnsworth@onelan.co.uk>
Date: Tue Feb 10 18:38:08 2015 +0000
drm/dp: Use large transactions for I2C over AUX
[2015-07-25 10:30] [ALPM] upgraded linux (4.0.7-2 -> 4.1.2-2)
[2015-07-25 10:31] [ALPM] upgraded xf86-video-intel (1:2.99.917+364+gb24e758-1 -> 1:2.99.917+381+g5772556-1)
[2015-07-25 10:31] [ALPM] upgraded xorg-server-common (1.17.2-3 -> 1.17.2-4)
[2015-07-25 10:31] [ALPM] upgraded xorg-server (1.17.2-3 -> 1.17.2-4)
[2015-07-25 10:31] [ALPM] upgraded xorg-server-xvfb (1.17.2-3 -> 1.17.2-4)
My Thinkpad T550 mini display port is no more working.
Do I need to downgrade kernel and or xf86 etc.. ?
the relevant information. It seems not so easy to do, I do not want to again
break my machine by downgrading.
I switched to VGA monitor for now.
If you have an easy way, can link to the relevant wiki page, it would be great.
Thanks for your bug report thought, good community work!
Don't you think we should report this to the kernel bug tracker?
Here is the related wiki entry: https://wiki.archlinux.org/index.php/Downgrading_packages#Downgrading_the_kernel
You don't need to boot from a live CD, just go to /var/cache/pacman/pkg and install the appropriate kernel Version.
It's connected to a HDMI screen through a mini display port => HDMI cable.
It stopped working right after upgrading (yesterday):
[2015-07-25 10:30] [ALPM] upgraded linux (4.0.7-2 -> 4.1.2-2)
[2015-07-25 10:31] [ALPM] upgraded xf86-video-intel (1:2.99.917+364+gb24e758-1 -> 1:2.99.917+381+g5772556-1)
[2015-07-25 10:31] [ALPM] upgraded xorg-server-common (1.17.2-3 -> 1.17.2-4)
[2015-07-25 10:31] [ALPM] upgraded xorg-server (1.17.2-3 -> 1.17.2-4)
[2015-07-25 10:31] [ALPM] upgraded xorg-server-xvfb (1.17.2-3 -> 1.17.2-4)
I do think that it's exactly the same patch that is causing this, otherwise it would be a hell of a coincidence.
Intel chipset is i915:
00:02.0 VGA compatible controller: Intel Corporation Broadwell-U Integrated Graphics (rev 09)
Subsystem: Lenovo Device 2223
Kernel driver in use: i915
Kernel modules: i915
What do you think?
Do we need to open a bug report on feredesktop or kernel.org?
https://bugs.freedesktop.org/show_bug.cgi?id=91451