Bug 485477

Summary:	Incorrect nm-applet menu signal strength with multiple APs
Product:	Red Hat Enterprise Linux 5	Reporter:	Dan Williams <dcbw>
Component:	NetworkManager	Assignee:	Dan Williams <dcbw>
Status:	CLOSED ERRATA	QA Contact:	desktop-bugs <desktop-bugs>
Severity:	medium	Docs Contact:
Priority:	low
Version:	5.3	CC:	cmeadors, rlerch, zcerza
Target Milestone:	rc
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:	Due to faulty logic in the code, nm-applet would choose the lowest signal strength of all APs of the same SSID in the area and display this strength in the menu to represent the signal strength for that SSID. Any SSID with more than one AP would therefore appear to have a weaker signal than it really did. The logic srror is corrected, and NetworkManager now correctly calculates wireless signal strength when multiple access points with the same SSID are present.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2009-09-02 11:54:16 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Dan Williams 2009-02-13 17:47:54 UTC

Best-signal-strength calculation was incorrect.  Trivial patch below; upstream commits r1159 (trunk) and 1161 (0.7)

Index: src/applet-device-wifi.c
===================================================================
--- src/applet-device-wifi.c	(revision 1157)
+++ src/applet-device-wifi.c	(working copy)
@@ -581,7 +578,7 @@ add_one_ap_menu_item (NMDeviceWifi *devi
 		item = NM_NETWORK_MENU_ITEM (dup_data.found);
 
 		/* Just update strength if greater than what's there */
-		if (nm_network_menu_item_get_strength (item) > strength)
+		if (nm_network_menu_item_get_strength (item) < strength)
 			nm_network_menu_item_set_strength (item, strength);
 
 		nm_network_menu_item_add_dupe (item, ap);

Comment 1 Cameron Meadors 2009-03-18 16:22:21 UTC

How does one discern that the best signal strenght calulation was incorrect from an end user point of view?

Comment 2 Dan Williams 2009-03-18 16:33:27 UTC

In an area with multiple APs, buggy nm-applet would always show the lowest signal strength of all APs of the same SSID in the menu.  Updated NM should show much higher signal strength for a laptop in the same location.  Would be sufficient to:

1) Find an area with multiple APs using the same SSID and security-settings (RH Westford will work fine for this)
2) Set up machine with updated/fixed NM; copy /usr/bin/nm-applet to a temp directory
3) Install old NM on the machine, reboot
4) On login, take a screenshot of the applet menu (use 'gnome-screenshot --delay=10' from a terminal, then open the applet menu, and wait for the screenshot)
5) killall -TERM nm-applet
6) /path/to/temp/nm-applet
7) take a screenshot of the menu again

comparing the two screenshots should show greatly increased signal strength for the SSID in question (ie, rh-wireless).  The key is to try to make steps 4 - 7 fairly quick; they should be able to be done in less than 15 seconds.  The reason to do the temp nm-applet dance is to ensure that the new applet (where the change actually is) is using the same dbus data as the old nm-applet, but presenting it correctly.

The test could also be done by taking screenshots of the old applet a few times over 15 minutes, then installing the new NetworkManager RPMs, rebooting, and then taking screenshots of the new nm-applet over a period of 15 minutes, and comparing the old and new screenshots.  You should see substantially better "signal strength" in the menu of the new applet.

Comment 4 Dan Williams 2009-05-04 16:04:51 UTC

nm-applet-0.7-ap-menu-strength-rh485477.patch

Comment 6 Ruediger Landmann 2009-05-25 02:11:02 UTC

Release note added. If any revisions are required, please set the 
"requires_release_notes" flag to "?" and edit the "Release Notes" field accordingly.
All revisions will be proofread by the Engineering Content Services team.

New Contents:
Due to faulty logic in the code, nm-applet would choose the lowest signal strength of all APs of the same SSID in the area and display this strength in the menu to represent the signal strength for that SSID. Any SSID with more than one AP would therefore appear to have a weaker signal than it really did. The logic srror is corrected, and NetworkManager now correctly calculates wireless signal strength when multiple access points with the same SSID are present.

Comment 7 Zack Cerza 2009-06-15 17:06:24 UTC

Verified on NetworkManager-0.7.0-7.el5.{i386,x86_64}.

Comment 9 errata-xmlrpc 2009-09-02 11:54:16 UTC

An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHBA-2009-1389.html