rtl8723au dropping wifi and system lock ups

[kl0211]

I am using the Lenovo Yoga 14 ultrabook with this driver. For a while I've been using Debian testing/unstable with the driver from the master branch and have had no issues come up. However, recently I upgraded to kernel version 3.16, and since that version includes the driver already, I had to use that one.

Here's where some issues come up. When using kernel 3.16, I notice the wifi signal just drops randomly, but not while it is actually downloading/uploading data, only if it has gone idle for a few moments at least. When this happens, it seems the only way to get wifi back is to turn the wireless off and back on.

The issue with the system lock ups are very peculiar. Sometimes it just happens immediately after logging in, and other times, it happens seveal minutes later. I am mostly certain that the lockups are caused by the wifi, since it does not happen when I turn wireless off.

I also tried installing other distros with kernel 3.16, notably Ubuntu 14.10 and Arch. Both have the same issues described. I went back to Debian and installed kernel 3.14 and compiled the driver in the master branch, and none of these issues are present.

[lwfinger]

What makes you think you need to use the built-in driver with kernel 3.16? If you blacklist r8723au and do a "sudo make install", you will geet the driver from the repo, not the kernel.

[kl0211]

Whenever I tried "modprobe 8723au" after make installing it, I get the message "Device or resource busy", even after putting "blacklist r8723au" in /etc/modprobe.d/blacklist.conf. I am by no means an expert with modules, so I might be doing it wrong. Documentation on this stuff is pretty hard to find.

[lwfinger]

If you blacklisted r8723au and installed 8723au, then after reboot, lsmod should show 8723au and not r8723au. At that point, modprobe will not be required.

[kl0211]

OK. So I tried it again, rebooted and, surprise suprise, it worked. r8723au was properly blacklisted, and the 8723au is working now on kernel 3.16. A few hours of testing and there were no dropped connections. There were a few messages in network-manager saying the connection failed, but it still ran and I could browse the web uninterrupted. No lock ups have happened so far.

If there is anything I can do to help diagnose the problems with the built-in kernel drivers, I'd be more than willing.

EDIT: Oh by the way, I think the reason it didn't work before might have been because I didn't run update-initramfs.

[laptander]

Yes, I can confirm. For example, if I play some long 3 hours video on youtube, then there are less disconnections than if wifi is just idling.

[vak]

@lwfinger, man, could you teach those linux kernel devs how to incorporate a reliably working driver code without breaking things? Or at least teach them how to fix their wrong integration job in less than 100 days?

P.S. just reverted back to lwfinger's driver after having tones of P.I.T.A. with their built-in driver. Thank you for your great job, by the way.

[lwfinger]

You need to bisect the kernel driver to point out exactly which commit broke the code. Just complaining about it gets nowhere. If the maintainers computer had the problem, he would fix it. It seems that there is something "special" about your system, thus only you can find the exact problem.

As I have said many times before, I do not have the hardware. For that reason, I cannot make any tests.

[cekajot]

Guys, I signed up just to THANK YOU. I had the same issue and I searched WEEKS for a solution. I an absolute Linux Newbie, and due to the wifi problems I was even thinking about switching back to a
Mac. But now the wifi does not disconnect and it seems 10 times faster and I am really enjoying my new OS. Thank you so much!