RTL8192SU: Slow wireless in 12.04

[JohnDillinger43]

When I upgraded to 12.04 I suddenly started experience really slow download speeds with my wireless adapter. I'm using a PremierTek PT-H10DN, which uses the RTL8192SU chipset. Since it worked perfectly out of the box with 11.10 and the trouble started as soon as I upgraded, I'm assuming this is a driver issue. I downloaded a driver from the RT site, but when I try to install it it asks for authentication and then says authentication failed. Not sure why this is, or if installing this driver will even fix the problem.

I've come across a lot of posts of people complaining of the same issue with different wireless adapters. I tried most of the fixes, e.g., disabling IPv6, but none of them fixed my problem.

[ahallubuntu]

By "authentication" you mean you are asked for a password but it is rejected? That should be your "sudo" or admin password...

[JohnDillinger43]

Yeah, I put in my sudo password, I get an error message, it asks again, and then it quits.

The RT help desk guy suggested uninstalling my current wireless driver and then trying again, but I don't know if that's the best course of action.

[JohnDillinger43]

Any ideas? I'm starting to wonder if it is a driver issue, because I got some pretty good results with speedtest.net the other morning. But now I'm back to d/l speeds <1Mbps and u/l speeds around 1Mbps (I consistently get faster upload speeds, no idea why this would be the case).

I'd suspect the positioning of my wireless adapter, but when I stick a laptop right in that spot the speed's just fine. For the same reason I'm loath to assume it's variability b/c I have cable internet; the other computers in the house always have decent speed.

[JohnDillinger43]

Still having this issue. Browsing the internet is like crawling over broken glass. Ping speeds to both the router and the printer that sites right next to this desktop are in the 100-300ms range (when it doesn't drop packets). I confirmed it's not a location issue; when I set our netbook next to the adapter and pinged from both computers the netbook got 10-40ms speeds and the desktop hundreds of ms. Since I disabled IPv6 on the desktop I tried also doing that on my router, but that did nothing.

Any suggestions would be appreciate, or I'd be glad to provide more information.

[ahallubuntu]

Try building the driver again. It sounds like you didn't succeed the first time.

Go back to the downloaded driver directory in a terminal and type

sudo bash install.sh

It should ask you only once this time.

If it rejects your password, you'll need to figure out what it is, sooner or later, to do any admin stuff in Ubuntu.

[JohnDillinger43]

Thanks for your post -- I wasn't doing sudo in my initial command (which is why it was asking for authentication), and once I did, the script ran. However, it didn't finish properly. I'm getting "Error 2" when I run it. I did find out using lshw that the driver I'm using is apparently rt2800, which seems very wrong (my chipset is 8192), so perhaps this is the problem. Now if only I can get the driver to install properly....

[JohnDillinger43]

I *think* I've got the driver installed. At the very least, the makefile seemed to work and I didn't get any errors. However, I'm not sure how to switch the driver over to the new one. The readme suggested [wireless] down and then up again, which I tried, but doesn't that just turn the wireless off and back on? Should that prompt it to load a different driver?

[ahallubuntu]

You can verify that the new driver has been installed by doing:

sudo lshw -C network

or

modinfo rtl8192su

(Assuming the module is called "rtl8192su" - if it's "8192su" use that instead.)

If the name has changed, you may have to add it to your /etc/modules file - not sure, I haven't used this exact driver before. With rtl8192cu, you have to blacklist that and load the new module name "8192cu" with /etc/modules .

[mikewhatever]

I *think* I've got the driver installed. At the very least, the makefile seemed to work and I didn't get any errors. However, I'm not sure how to switch the driver over to the new one. The readme suggested [wireless] down and then up again, which I tried, but doesn't that just turn the wireless off and back on? Should that prompt it to load a different driver?

You should blacklist the 'old' rtl8192su module, by adding it to /etc/modprobe.d/blacklist.conf. Running the following will do it.

echo 'blacklist rtl8192su' | sudo tee -a /etc/modprobe.d/blacklist.conf

Blacklisting will prevent it from auto-loading. Reboot, and then rebuild it once again.

PS: The problem with the 8192su is rather old. Here's a bug report.