I'm trying to get a reliable mini-dp to VGA connection for a dell XPS 13 (9343, Broadwell) to a projector in a lecture theatre. I have a couple of dongles - one Apple mini dp-VGA and one cheap mini dp to VGA/HDMI/DVI combo. Either works if I just connect to a monitor over a short cable. In the lecture theatre, the Apple dongle doesn't work at all, and the cheap combo adapter works sometimes, perhaps 1 in 3 times I plug it in. In windows the Apple dongle works fine. I have tried setting drm_kms_helper.dp_aux_i2c_transfer_size to 1 and 4 (which solved some problems with the apple adapter on ealier kernels) but this doesn't seem to make a difference now. I'm running Arch linux, with kernel 4.6.0, xorg-server-1.18.3-2, xf86-video-intel-1:2.99.917+662+gb617f80-1 Setting drm.debug=14, The Apple dongle shows me: [ 3134.274766] [drm:intel_get_hpd_pins] hotplug event received, stat 0x00200000, dig 0x10101012, pins 0x00000020 [ 3134.274775] [drm:intel_hpd_irq_handler] digital hpd port B - long [ 3134.274779] [drm:intel_hpd_irq_storm_detect] Received HPD interrupt on PIN 5 - cnt: 0 [ 3134.274801] [drm:intel_dp_hpd_pulse] got hpd irq on port B - long [ 3134.275271] [drm:intel_dp_get_dpcd] DPCD: 11 0a 82 01 00 03 01 81 00 00 00 00 00 00 00 [ 3134.275278] [drm:intel_dp_get_dpcd] Display Port TPS3 support: source yes, sink no [ 3134.275285] [drm:intel_dp_print_rates] source rates: 162000, 270000, 540000 [ 3134.275289] [drm:intel_dp_print_rates] sink rates: 162000, 270000 [ 3134.275293] [drm:intel_dp_print_rates] common rates: 162000, 270000 [ 3134.276100] [drm:intel_dp_probe_oui] Sink OUI: 000000 [ 3134.276453] [drm:intel_dp_probe_oui] Branch OUI: 0010fa [ 3134.276467] [drm:i915_hotplug_work_func] running encoder hotplug functions [ 3134.276472] [drm:i915_hotplug_work_func] Connector DP-1 (pin 5) received hotplug event. [ 3134.276476] [drm:intel_dp_detect] [CONNECTOR:45:DP-1] [ 3134.277469] [drm:intel_dp_get_dpcd] DPCD: 11 0a 82 01 00 03 01 81 00 00 00 00 00 00 00 [ 3134.277475] [drm:intel_dp_get_dpcd] Display Port TPS3 support: source yes, sink no [ 3134.277482] [drm:intel_dp_print_rates] source rates: 162000, 270000, 540000 [ 3134.277488] [drm:intel_dp_print_rates] sink rates: 162000, 270000 [ 3134.277493] [drm:intel_dp_print_rates] common rates: 162000, 270000 [ 3134.278394] [drm:drm_dp_i2c_do_msg] native defer [ 3134.279464] [drm:drm_dp_i2c_do_msg] native defer [ 3134.280620] [drm:drm_dp_i2c_do_msg] I2C nack (result=0, size=0 [ 3134.281072] [drm:drm_dp_i2c_do_msg] native defer [ 3134.282332] [drm:drm_dp_i2c_do_msg] native defer [ 3134.283424] [drm:drm_dp_i2c_do_msg] native defer [ 3134.284222] [drm:drm_dp_i2c_do_msg] I2C nack (result=0, size=0 [ 3134.284665] [drm:drm_dp_i2c_do_msg] native defer [ 3134.285917] [drm:drm_dp_i2c_do_msg] native defer [ 3134.286997] [drm:drm_dp_i2c_do_msg] native defer [ 3134.287774] [drm:drm_dp_i2c_do_msg] I2C nack (result=0, size=0 [ 3134.288208] [drm:drm_dp_i2c_do_msg] native defer [ 3134.289412] [drm:drm_dp_i2c_do_msg] native defer [ 3134.290480] [drm:drm_dp_i2c_do_msg] native defer [ 3134.291255] [drm:drm_dp_i2c_do_msg] I2C nack (result=0, size=0 [ 3134.291687] [drm:drm_dp_i2c_do_msg] native defer [ 3134.292891] [drm:drm_dp_i2c_do_msg] native defer [ 3134.293960] [drm:drm_dp_i2c_do_msg] native defer [ 3134.294733] [drm:drm_dp_i2c_do_msg] I2C nack (result=0, size=0 [ 3134.295165] [drm:drm_dp_i2c_do_msg] native defer [ 3134.295946] [drm:intel_dp_detect_dpcd] Broken DP branch device, ignoring [ 3134.295949] [drm:i915_hotplug_work_func] Connector HDMI-A-1 (pin 5) received hotplug event. [ 3134.295951] [drm:intel_hdmi_detect] [CONNECTOR:49:HDMI-A-1] [ 3134.296187] [drm:do_gmbus_xfer] GMBUS [i915 gmbus dpb] NAK for addr: 0050 w(1) [ 3134.296189] [drm:do_gmbus_xfer] GMBUS [i915 gmbus dpb] NAK on first message, retry [ 3134.296391] [drm:do_gmbus_xfer] GMBUS [i915 gmbus dpb] NAK for addr: 0050 w(1) [ 3134.296393] [drm:drm_do_probe_ddc_edid] drm: skipping non-existent adapter i915 gmbus dpb [ 3134.480116] [drm:intel_get_hpd_pins] hotplug event received, stat 0x00200000, dig 0x10101011, pins 0x00000020 [ 3134.480120] [drm:intel_hpd_irq_handler] digital hpd port B - short [ 3134.480141] [drm:intel_dp_hpd_pulse] got hpd irq on port B - short [ 3136.805463] [drm:drm_mode_addfb2] [FB:55] I can provide dmesg traces for other situations if that's at all helpful.
Please try current drm-intel-nightly kernel from http://cgit.freedesktop.org/drm-intel
Created attachment 126637 [details] dmesg trace with Apple VGA dongle, using drm-intel-nightly Sept 19 I built the drm-intel-nightly kernel, but sadly it doesn't seem to improve things for the VGA dongles. dmesg trace attached.
Information provided, moving bug back to New
Hello, I tried to reproduce this issue but i was unable to get it, maybe it could be a problem with the projector or with the dongles. this is my current configuration: ====================================== Graphic stack ====================================== ====================================== Software ====================================== kernel version : 4.12.0-rc3-drm-tip-ww22-commit-187376e+ architecture : x86_64 os version : Ubuntu 17.04 os codename : zesty kernel driver : i915 bios revision : 5.6 bios release date : 05/11/2017 ====================================== Graphic drivers ====================================== mesa : 17.0.3 modesetting : modesetting_drv.so xorg-xserver : 1.19.3 libdrm : 2.4.81 cairo : 1.14.8 xserver : X.Org X Server 1.19.99.1 intel-gpu-tools (tag) : intel-gpu-tools-1.18-211-g00ce341b intel-gpu-tools (commit) : 00ce341b ====================================== Hardware ====================================== platform : BDW motherboard id : NUC5i7RYB form factor : Desktop cpu family : Core i7 cpu family id : 6 cpu information : Intel(R) Core(TM) i7-5557U CPU @ 3.10GHz gpu card : Intel Corporation Iris Graphics 6100 (rev 09) (prog-if 00 [VGA controller]) memory ram : 15.58 GB max memory ram : 16 GB display resolution : 1600x900 cpu thread : 4 cpu core : 2 cpu model : 61 cpu stepping : 4 socket : Socket BGA1168 signature : Type 0, Family 6, Model 61, Stepping 4 hard drive : 111GiB (120GB) current cd clock frequency : 337500 kHz maximum cd clock frequency : 540000 kHz displays connected : DP-1 ====================================== Firmware ====================================== ====================================== kernel parameters ====================================== quiet splash fastboot drm.debug=0xe Carl could you try with the latest kernel xorg-server? Regards.
I haven't tried this in a long time - I've been able to use hdmi generally - and its always been reliable. This computer now has a 4.11.3 kernel on it. I went down to the lecture theatre just now with the apple VGA dongle and the situation is pretty different from when I first posted this. In all of the rooms where I could reproduce the problem, the projector switching system has been recently upgraded, so the newer kernel isn't the only difference. At the moment though, the apple dongle seems to work fine, as long as the dongle is plugged into the projector switch before its plugged into the laptop. If you plug the dongle in to the computer first, then plug the VGA cable in to the dongle afterwards, it doesn't work. If you'd like traces of those I can post them.
(In reply to Carl Michal from comment #5) > I haven't tried this in a long time - I've been able to use hdmi generally - > and its always been reliable. > > This computer now has a 4.11.3 kernel on it. I went down to the lecture > theatre just now with the apple VGA dongle and the situation is pretty > different from when I first posted this. In all of the rooms where I could > reproduce the problem, the projector switching system has been recently > upgraded, so the newer kernel isn't the only difference. Hello Carl, Since all the configuration had changed already, it seems really hard to point a culprit now. > > At the moment though, the apple dongle seems to work fine, as long as the > dongle is plugged into the projector switch before its plugged into the > laptop. If you plug the dongle in to the computer first, then plug the VGA > cable in to the dongle afterwards, it doesn't work. > About the dongle, seems more probably that the cable or the dongle are the cause of the problem than any SW configuration. I recommend to try a different cable and dongle to see if the problem is caused for those ones. If the problem is not present anymore, please change the status to RESOLVED. Thank you.
I can't really object to closing this since I can't reproduce it. I don't think this was a cable or dongle problem since it appeared with two different dongles in a couple of different lecture theatres, and all of the same hardware worked without any problems in windows. If I see the problem again and can reproduce it I'll open a new bug.
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