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Issue 606514 link

Starred by 4 users

Issue metadata

Status: WontFix
Owner:
Closed: Oct 2016
Cc:
Components:
EstimatedDays: ----
NextAction: ----
OS: Chrome
Pri: 2
Type: Bug



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high packet loss when switching resolution from 1280x1024 to 1600x1200 (native)

Project Member Reported by semenzato@chromium.org, Apr 25 2016

Issue description


We have a Speedy user who's experiencing Wi-Fi disconnects after going into docked mode.  After they change resolution they claim the device disconnects.  

Video: https://drive.google.com/a/google.com/file/d/0B01J1NaYR2sOZHAyekQwMWNfRjA/view

Chromebook Central: https://productforums.google.com/forum/#!topic/chromebook-central/uQPCC_Et1rQ;context-place=forum/chromebook-central

Feedback report:
https://hotsauce.corp.google.com/product/208/neutron?l=true&lView=rd&lRSort=1&lROrder=2&lRFilter=1&lReport=7960533157

(also search for more reports by the same user)




 
The customer is right---there is an almost perfect correlation between switching resolution on the external monitor and losing packets.  However, the video shows *one* lonely ping packet going through at the higher resolution, so we're still connected.  Jian also noted this.

Could it be interference from the display?  I will ask the user to try to move the chromebook further away.
Cc: shrawan@chromium.org tienchang@chromium.org ka...@chromium.org
Components: OS>Kernel>Video OS>Systems>Network
Labels: OS-Chrome

Comment 3 by jleong@chromium.org, Apr 25 2016

Cc: -ka...@chromium.org kirtika@chromium.org snanda@chromium.org
Owner: ka...@chromium.org
Status: Assigned (was: Untriaged)
Kalin and Shrawan will help repro.
Actually I am wondering if we should try to repro here.  It may be difficult.  Customer has a repro case, and he's running in dev mode (he's posted the output of "cat /var/log/net.log").

Comment 5 by ka...@chromium.org, Apr 25 2016

Shrawan was able to reproduce similar behavior on the current M49 stable build when 'ping yahoo.com'(but not other domain names - amazon.com and facebook.com), even without docking the device, but changing external display resolution, and switching back resolution did not connect back while plugged to monitor. Logs are attached at
https://pantheon.corp.google.com/storage/browser/chromiumos-test-logs/bugfiles/cr/606514/

Shrawan, please update status for M50 build(current beta and soon to be pushed as stable) version on the same speedy board.
From the log posted by the customer in the CB Central thread from comment #0, I get this:

10:49:39 wifi starts connecting
      42 online
      50 lost connection

followed by many connection attempts and a few scans.  All attempts fail with ASSOCIATING -> DISCONNECTED.  The last failures is at 10:51:38, almost two minutes later.  Finally wifi goes online at 10:51:54.

The kernel log shows nothing interesting.  I have asked the customer to reproduce the experiment and collect /var/log/messages instead of dmesg.
The behavior at #6 is consistent with interference.

#5: amazon.com doesn't respond to ping, but facebook.com does.  So it's a little strange that the behavior was different between the two.

#5: how did you change the external display resolution without connecting the device?  Are we talking about an HDMI cable or is there some kind of dock?  Thanks!

Comment 8 by shrawan@google.com, Apr 25 2016

Not able to reproduce this on M-50 (7978.62.0) build with a Dell monitor. I changed the resolution with 1920x1080 (default), 1920x1200, 1600x1200, 1680x1050 and 1024x768 while pinging "yahoo.com" and didn't see any ping stall.



 

Comment 9 by ka...@chromium.org, Apr 25 2016

Docking - meaning closing the lid while plugged external display - the primary screen transfers to external display and DUT is docked.
#CBC-RS/TC-watchlist

Kalin, thank you for #9, and also I meant to say that it's great that we can reproduce (#5)---I apologize for not conveying my enthusiasm!!! 

One theory is that some harmonic of the display clock interferes with the wifi band in use.  If you have a repro case, would it be hard to try connecting to an AP with a fixed channel, and try different channels to see if it makes a difference?

Comment 12 by ka...@chromium.org, Apr 26 2016

Tien and Shrawan, please follow the suggestion from semenzato@.
I agree that connecting the monitor does not disconnect network.

Usually I see DNS related errors
64 bytes from lhr26s01-in-f142.1e100.net (216.58.213.142): icmp_seq=24 ttl=58 time=31.3 ms
64 bytes from 216.58.213.142: icmp_seq=25 ttl=58 time=1214 ms
ping: sendmsg: Network is unreachable

and in net.log
WARNING shill[953]: [WARNING:traffic_monitor.cc(226)] DNS queries failing, out-of-credits?

and unable to reconnect back, if I try to connect manually WPA password would be requested but if I leave it and drop the resolution or disconnect monitor it will reconnect automatically.

ERR shill[953]: [ERROR:wifi.cc(968)] Disconnected due to inability to connect to the service.
ERR shill[953]: [ERROR:logging.h(842)] Failed to call method: fi.w1.wpa_supplicant1.Interface.Disconnect: object_path= /fi/w1/wpa_supplicant1/Interfaces/0: fi.w1.wpa_supplicant1.NotConnected: This interface is not connected
ERR shill[953]: [ERROR:dbus_method_invoker.h(111)] CallMethodAndBlockWithTimeout(...): Domain=dbus, Code=fi.w1.wpa_supplicant1.NotConnected, Message=This interface is not connected
ERR shill[953]: [ERROR:chromeos_supplicant_interface_proxy.cc(198)] Failed to disconnect: fi.w1.wpa_supplicant1.NotConnected This interface is not connected
ERR shill[953]: [ERROR:wifi.cc(968)] Disconnected due to inability to connect to the service.
shill[953]: [ERROR:logging.h(842)] Failed to call method: fi.w1.wpa_supplicant1.Interface.Disconnect: object_path= /fi/w1/wpa_supplicant1/Interfaces/0: fi.w1.wpa_supplicant1.NotConnected: This interface is not connected
ERR shill[953]: [ERROR:dbus_method_invoker.h(111)] CallMethodAndBlockWithTimeout(...): Domain=dbus, Code=fi.w1.wpa_supplicant1.NotConnected, Message=This interface is not connected
ERR shill[953]: [ERROR:chromeos_supplicant_interface_proxy.cc(198)] Failed to disconnect: fi.w1.wpa_supplicant1.NotConnected This interface is not connected

Please note the ChromeOS version is now  different:
Version 50.0.2661.94
Platform 7978.69.0 (Official Build) stable-channel veyron_speedy
Firmware Google_Veyron_Speedy.6588.160.0

As I have mentioned in another email with this version I cannot set external monitor as primary, which makes it a bit more difficult.

The monitors are EIZO RadiForce RX211 and NEC MultiSync LCD2190UXP.
net.log
359 KB View Download
messages
98.1 KB View Download

Comment 14 by ka...@chromium.org, Oct 24 2016

Status: WontFix (was: Assigned)

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