The Newest Dropbox version seems to follow Linux Power-Saving Behavior.

As of an earlier posting, I had “Dropbox” v3.16.1 running on my KDE-4 Linux desktop. This version has updated itself to v3.18.1 . Additionally, I have this Dropbox client installed and idling, on the Linux laptop I name ‘Klystron’.

I see one significant new behavior. When I have left my laptop idle, with the screen turning off, the little Dropbox icon changes to show that it has dropped its connection to the Dropbox server. This is similar to behavior which my “Pidgin” IRC client has shown, and seems to suggest, that there are power-saving measures in place on up-to-date Linux desktop managers, which certain applications may opt to use.

The ‘KDE’ desktop manager has in common with ‘GNOME’, that both now use ‘DBUS’ as their inter-process communication system. So what works under GNOME, will frequently also work under KDE when properly set up.

But the fact that both Pidgin and Dropbox seem to do this on my laptop, means that I do not have to keep looking as hard as before, for causes within the kernel module of my laptop WiFi, for possible connection issues. In both cases, the software seems to reconnect to its server, as soon as I have unlocked my screensaver.

Unlocking the screensaver is an event, which a kernel module usually does not recognize.

(Edit 04/17/2016 : ) One way in which such a power-saving mode would make sense however, is that the Kernel can recognize it, and can give the software command to the Kernel Module, to turn off its antenna as well. However, according to This Posting, I have forbidden the KM from following such a command, such that the antenna does not switch off.

Depending on what software we have installed, simply having the WiFi turn off, can cause problems.

Dirk

 

My WiFi connection has been stable, for 1 day and 13 hours.

On my newly set-up laptop ‘Klystron’ I had reported This Problem with the stability of the WiFi chip-set. Well since that posting, that laptop has been able to stay idle – and connected – for 1 day and 13 hours, without disconnecting. And, I have downloaded lengthy hundreds of megabytes – and sometimes gigabytes – of software packages, without any further interruptions.

Thus, even if there is still a problem with my Pidgin client sometimes disconnecting with a “Ping Timeout”, this problem should be external to the behavior of the WiFi kernel module now, and may even have something to do with policies from the IRC chat room, such as ‘No More Than 1 Nick Per User Logged On At Once’ ?

Dirk

 

My Latest Experiment with Pidgin and WiFi seems a success.

In This Posting, I described how the remaining WiFi-behavior of my laptop ‘Klystron’, that I wanted to change was, that if I left the laptop unattended for a few hours, the ‘Pidgin’ IRC client would disconnect. At first, I thought that maybe this was another behavior of the Realtek chip-set. But this time, it was not.

Last night I had installed the Pidgin plugin ‘Away-On-Lock’, which was not installed when this misbehavior was taking place. And I seem to have replaced this behavior successfully, with only showing the chat-room that I am Away, if I leave that laptop idle for a few hours.

Dirk

 

Stabilizing my Realtek rtl8723be WiFi card under Linux.

The laptop of mine onto which I newly installed Kanotix / Spitfire, and that is named ‘Klystron’, happens to have a Realtek rtl8723be WiFi chip-set, which is known to have stability issues under Linux. I found that recently my own experience also ran into these issues.

If you feel that you are also having these issues, it is important that you first check, whether in fact you have the WiFi card in question. This can be done via an ‘lspci‘ command, or with


lsmod | grep rtl8723

I felt that I needed to apply a two-prong solution to my own problem.

The first thing which I did, was to create a file named


/etc/modprobe.d/rtl8723be.conf

The only content of which was the line


options rtl8723be fwlps=0 swlps=0

This solution may solve the problem, of the WiFi dropping the connection, after periods of idle time.

There is something to watch out for. There are some sources on the Web, which state that we should try  the configuration line


options rtl8723be fwlps=N swlps=N

The problem with this method is, that for certain uses in programming, in particular in the language C, which is used for kernel modules, a numeric value may be expected in place of a Boolean value, and if in this case the module sees an ‘N’, this value will not be equal to zero, because the ASCII code for ‘N’ is not zero, and any other value than zero is taken to be True! So to make sure that the kernel module registers False, we need to put a ‘0’.

But I found that a second issue was affecting me, which was the fact that this WiFi setup has IPv6 enabled, but that my router does not tolerate IPv6. This may have been causing my laptop to get dropped from the WiFi, even as I was downloading software. In my dhcp configuration, I have added the DNS Server 8.8.8.8, which is the free Google DNS server, in addition to the auto-detected server. But 8.8.8.8 will offer the system an IPv6 resolution of a domain name along with an IPv4 resolution, and in the case of WiFi, apparently Linux will use the IPv6, without detecting that this ability was not assigned by the Access Point.

And so I felt that I also needed to disable IPv6 system-wide on this laptop. The way to do that was to add the following lines to the file ‘/etc/sysctl.conf‘:


net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1

And then ‘sysctl -p‘. After that, I also did


update-initramfs -u

This is a very sticky issue, in which different users have reported, that some of these solutions either do or do not work for them. One reason may be, that users are in fact reporting different issues without knowing it. I cannot be sure that this solution will remain 100% effective for myself, let alone for the reader. I just wanted to share my own experience with this. So far, my WiFi chipset is stable again.

(Edit 04/12/2016 : ) Just to prove to you, how uncertain the state of that WiFi chip-set is, even though I did change the parameters fed into this kernel module, it still happens that when I leave that laptop idling overnight, its WiFi goes into suspend mode. This happens in a way which the applications usually do not see, so that those applications still think they’re connected. However, my ‘Pidgin’ IRC Client gets disconnected.

And then, when I resume my session, ‘Pidgin’, which uses a ping timeout, did realize it was disconnected, and just reconnects seamlessly. And this latter part seems to happen, directly after I unlock my screen-saver, which seems to suggest that this is not being introduced by the Kernel Module, but rather by KDE, etc. I suppose it might introduce some level of confusion into the software, if the Kernel Module was to provide the same function again.

So who knows, which of my problems – if any – I may really have fixed?

Just checking my package manager, I see that ‘Pidgin’ has an available ‘Away-On-Lock’ plugin, which was not installed. Just this evening I installed and activated that, just to see whether I can override a behavior, which might have been set erroneously to ‘Offline-On-Lock’, while the plugin was not installed… By tomorrow, I should know.

Dirk