Bug 59261

Summary:	TX power change causing WiFi stability issues.
Product:	Networking	Reporter:	Ryan P.C. McQuen (ryanpcmcquen)
Component:	Wireless	Assignee:	Stanislaw Gruszka (stf_xl)
Status:	RESOLVED PATCH_ALREADY_AVAILABLE
Severity:	high	CC:	linville, ryanpcmcquen, stf_xl
Priority:	P1
Hardware:	All
OS:	Linux
Kernel Version:	Since 3.8.x	Subsystem:
Regression:	Yes	Bisected commit-id:
Attachments:	Patch supplied by Mike Romberg.

Description Ryan P.C. McQuen 2013-06-03 17:59:35 UTC

Created attachment 103301 [details]
Patch supplied by Mike Romberg.

Related to this bug:
https://bugzilla.redhat.com/show_bug.cgi?format=multiple&id=950735

WiFi stability has regressed on certain cards because of the change in TX power.

Attached patch fixes the issue (works with Kernel 3.9.4).

Comment 1 Stanislaw Gruszka 2013-06-04 08:44:52 UTC

Please provide information about your Ralink chipset , it should be printed in dmesg. For example my chip is like below:
[ 2380.163512] ieee80211 phy4: rt2x00_set_rt: Info - RT chipset 3572, rev 0223 detected
[ 2380.178868] ieee80211 phy4: rt2x00_set_rf: Info - RF chipset 0009 detected

Comment 2 Ryan P.C. McQuen 2013-06-04 14:16:33 UTC

Can't seem to find it with dmesg, here's what I get from lspci:

02:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 06)
03:00.0 Network controller: Ralink corp. RT5390 Wireless 802.11n 1T/1R PCIe

Thank you!

Comment 3 Stanislaw Gruszka 2013-06-05 09:01:17 UTC

I wish to know detailed chipset revision. This is printed by default to dmesg starting from 3.9 kernel. Older kernels have to be compiled with CONFIG_RT2X00_DEBUG to get that information.

Comment 4 Ryan P.C. McQuen 2013-06-06 00:23:51 UTC

Here's dmesg on the 3.9.4 kernel:

[    8.306092] phy0 -> rt2x00_set_chip: Info - Chipset detected - rt:5390, rf: 5390, rev: 0502.
[    8.387344] phy0 -> rt2x00lib_request_firmware: Info - Loading firmware file 'rt2860.bin'.
[    8.440968] phy0 -> rt2x00lib_request_firmware: Info - Firmware detected - version: 0.34.

Thank you.

Comment 5 Stanislaw Gruszka 2013-06-08 17:44:10 UTC

I attached different patch at RH bugzilla
https://bugzilla.redhat.com/attachment.cgi?id=758600
Please test if it also prevent the problem.

Comment 6 Ryan P.C. McQuen 2013-06-08 20:59:53 UTC

Thank you Stanislaw. Will this also help 3.8.13 and Broadcom chips (that are having similar issues)?

Comment 7 Stanislaw Gruszka 2013-06-08 21:48:17 UTC

No, that patch is Ralink specific, it affect only RT5390 and RT3290 chips.

Comment 8 Ryan P.C. McQuen 2013-06-08 21:51:18 UTC

Is there a possible universal fix?

Comment 9 Stanislaw Gruszka 2013-06-09 08:43:28 UTC

No. Problem reported in RH bugzilla is rt2x00 specific. You have to open a separate bug report for Broadcom issue.

Comment 10 Stanislaw Gruszka 2013-06-12 10:52:41 UTC

Patch addressing this bug was posted:
http://marc.info/?l=linux-wireless&m=137096920914837&w=2

Comment 11 Ryan P.C. McQuen 2013-06-12 13:04:16 UTC

Thank you Stanislaw. Things are working nicely for me on the vanilla 3.9.5 kernel.