Wifi speeds slow down to a trickle after suspending laptop

Dan733

I've been using Solus for about a month now and I've been loving it. It is noticeably snappier than Ubuntu on my surface pro 3. However, I have an issue where, if I suspend my laptop, my internet speeds will slow to under .5mbps. I've done some testing and verified it's definitely a problem with the laptop and not my internet.

Some internet sleuthing has led me to believe this could be a problem with the wifi power management, however, commands I've found to disable this feature don't seem to work on Solus. I would appreciate any advice!

Dan733

I hate to reply to my own post, but right now I have to restart my computer every time I put it to sleep, so I'd love some help!

WetGeek

Dan733 right now I have to restart my computer every time I put it to sleep, so I'd love some help!

I'm experiencing the same sort of problem with my desktop workstation, but it happens when I use Super+'L' to lock the screen between sessions. When I want to use the computer again, nothing I can do with the mouse or keyboard will get the thing active again ... I have to shut down manually and restart the machine. It's the one and only computer here that acts that way. All the laptops and the media machine re-activate with a bit of mouse movement or keyboard activity.

tomscharbach

I cannot replicate the issue you are reporting on a Dell Latitude 7280 running Solus Budgie. I checked with a friends (one using Solus Budgie, one using Ubuntu 20.04 and the other using Ubuntu 20.10, and none have the issue.

I also spent about an hour on the internet searching "wifi" "laptop" and "suspend" in various ways and cannot find any discussion of the issue.

However, I did find numerous discussions of wifi failing to resume after suspend on the Ubuntu forums, dating back a few years to the Linux 4.x era. Apparently the that issue was related to Linux kernel Bug 201469 (a PCI bus issue), which was resolved in later Linux kernel builds. If the issue you are having is recent (that is, first appeared after Solus moved to kernel 5.10), it is possible that your problem is related to a kernel bug in 5.10, but one that is not yet common enough to have been widely reported.

I don't know what brand/model laptop you are using, but the problem you are experiencing might be specific to a particular PCI bus or to a specific wifi adapter, so you might try searching for wifi/suspend issues relating to your particular hardware.

The only suggestion I have at this point is that you might consider changing your power management options, so that closing the lid puts the laptop into "hibernate" mode rather than "suspend" mode.

"Suspend" mode does not turn off your laptop, but instead puts the laptop all peripherals on a low power consumption mode; that would be consistent with throttled-down wifi performance upon resume if either the PCI bus or the wifi adapter was not restored to full power consumption on resume. "Hibernate" mode, in contrast, saves the state of the laptop to the hard disk and completely powers off; when resuming, the laptop powers on (and the saved state is restored to RAM), which should trigger full power consumption throughout the laptop.

Assuming that the change from "suspend" to "hibernate" resolves the slow-down issue, that's a workaround rather than a solution, but it might be less aggravating than restarting the laptop manually every time you open the lid.

Dan733

tomscharbach Really appreciate the detailed reply, Tom. I've had this problem on every linux flavor I've used, so it probably is a kernel problem. I'm using a surface pro 3, and hibernation does not seem to be an option in the power settings, so I have to make due with suspension.

On other linux distributions, I've been able to solve the issue by following one of the tutorials to disable wifi power management e.g. this one. However, this command fails in solus with error Error for wireless request "Set Power Management" (8B2C) : SET failed on device wlan0 ; No such device.
Perhaps there is a solus-specific command to disable wifi power management?

Brucehankins

I have similar issues with my WiFi, but it also happens randomly. I upgraded to an AX200 m.2 card and WiFi speeds will randomly drop to 30-60 kbps. Stay there for a bit, then pick back up. Usually, disabling WiFi and then turning it back on a minute or two later helps.

prateekmedia

Dan733 you may wanna type the full name of the wifi interface as the error states wlan0: no such device

Use this command to find the wifi interface name it should include wlan0 type of thing so it's easy to find that line.
cat /proc/net/wireless

Dan733

prateekmedia See, I had no idea what a wifi interface was, but you have opened my eyes. iwconfig lists my interface as wlp1s0, and sudo iwconfig wlp1s0 power off now successfully turns off wifi power management!! WOOHOO thanks for your help!!