FS#40905 - [linux] 3.15 awful ath9k_htc performance

Attached to Project: Arch Linux
Opened by Mike Swanson (chungy) - Thursday, 19 June 2014, 23:56 GMT
Last edited by Tobias Powalowski (tpowa) - Wednesday, 13 August 2014, 07:13 GMT
Task Type Bug Report
Category Kernel
Status Closed
Assigned To Tobias Powalowski (tpowa)
Thomas Bächler (brain0)
Architecture All
Severity Medium
Priority Normal
Reported Version
Due in Version Undecided
Due Date Undecided
Percent Complete 100%
Votes 13
Private No


Upon upgrading my system to linux-3.15.1, my wireless device connected to USB with the ath9k_htc chip cannot push out anything faster than ~140KB/s, whereas previously I was able to do 4 MB/s.

Additional info:
* linux-3.15.1-1 on x86_64
This task depends upon

Closed by  Tobias Powalowski (tpowa)
Wednesday, 13 August 2014, 07:13 GMT
Reason for closing:  Upstream
Comment by Ashiren (Ashiren) - Friday, 20 June 2014, 08:16 GMT
Agreed. I use usb wifi and i noticed the problem too. I couldn't get more than 50KB/s and ping was high too. I downgraded to 3.14 kernel and it works fine now.
Comment by Tobias Powalowski (tpowa) - Friday, 20 June 2014, 09:07 GMT
Please bisect and report upstream.
Comment by Natrio (natrio) - Saturday, 21 June 2014, 12:09 GMT Comment by Martin Dratva (raqua) - Saturday, 21 June 2014, 21:27 GMT
I do have the same problem.
Comment by Nat Zimmermann (natzim) - Monday, 23 June 2014, 22:48 GMT
+1 same problem
Comment by Trung Nguyen (Anomitee) - Friday, 27 June 2014, 11:29 GMT
I'm experiencing the same problem here as well. My USB wifi adapter uses the AR9271 chipset and my download drops from 28Mbps to 1-2Mbps.
Comment by Natrio (natrio) - Friday, 27 June 2014, 11:50 GMT
Workaround from Damjan Georgievski:
> Setting the modprobe to "options ath9k_htc nohwcrypt=1"
Looks like problem is in hardware encryption with this driver. Software encryption works well.
Comment by I Said Socks (socks) - Saturday, 28 June 2014, 20:17 GMT
Which ML should I post if (I think) I've identified the foul commit?
Does the kernel bugzilla get attention from devs? (I don't have an account there either.)
Anyway, I'll put the info here first for those concerned.
This is my first bisect so I may or may not have done it right. For me, it's this commit that introduced the bug:

commit 88daf80dcca19ff995cc263592426f734a9702f3
Merge: 010d3c3 35582ad
Author: John W. Linville <linville@tuxdriver.com>
Date: Thu Feb 20 15:02:02 2014 -0500

Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next into for-davem

Interestingly, neither of the parents has the bug.
Please verify / resend. Thanks.

Edit: sent mail, not sure if the right places >.>
Comment by Stefano Finocchiaro (stefanuc111) - Friday, 11 July 2014, 21:36 GMT
I'm also experience the exact same problem, but actually there are no fix