[SOLVED] Weak Wifi Signal after waking up from hibernate

[pnbalaji]

Hi,

I have been using Mageia 5 XFCE since the day it was out and it is running fine with out any issues. Though there were minor issues, I was able to get them resolved either by myself or with the help of forum support.

I have a weird problem now. To save some power, I have configured my desktop to go on hibernate if the desktop is inactive for 2 hours. This is working fine. However, when I turn on the desktop later to wake it up from hibernate, it comes fine, but the WiFi signal is very weak most of the times. Mostly no bars will be active or only one bar will be active on the WiFi indicator in system tray.

Any one have any clues? Or any way to resolve this issue?

Thanks,
Balaji.

[doktor5000]

Maybe you need to disable the power management of the wifi chipset and set the send power to full/fixed. See e.g. viewtopic.php?p=46418#p46418

[pnbalaji]

Hi,

I tried ifconfig -a and the results are below.

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sudo ifconfig -a
ens33: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500
        ether 00:e0:4c:68:93:a0  txqueuelen 1000  (Ethernet)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        loop  txqueuelen 1  (Local Loopback)
        RX packets 170  bytes 14116 (13.7 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 170  bytes 14116 (13.7 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

wlp0s29f7u3: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.1.6  netmask 255.255.255.0  broadcast 192.168.1.255
        inet6 fe80::32b5:c2ff:fe13:81ce  prefixlen 64  scopeid 0x20<link>
        ether 30:b5:c2:13:81:ce  txqueuelen 1000  (Ethernet)
        RX packets 217  bytes 58678462 (55.9 MiB)
        RX errors 0  dropped 1322  overruns 0  frame 0
        TX packets 38  bytes 7017473 (6.6 MiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

wlp0s29f7u4: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.1.7  netmask 255.255.255.0  broadcast 192.168.1.255
        inet6 fe80::202:72ff:fe59:2cba  prefixlen 64  scopeid 0x20<link>
        ether 00:02:72:59:2c:ba  txqueuelen 1000  (Ethernet)
        RX packets 435705  bytes 651215731 (621.0 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 119980  bytes 10902592 (10.3 MiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0


I tried to disable the power management with the following commands, but it did not work.

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[bneelka@localhost ~]$ sudo iwconfig wlp0s29f7u3 power off
[sudo] password for bneelka:
Error for wireless request "Set Power Management" (8B2C) :
    SET failed on device wlp0s29f7u3 ; Operation not permitted.
[bneelka@localhost ~]$ sudo iwconfig wlp0s29f7u3 txpower fixed
Error for wireless request "Set Tx Power" (8B27) :
    GET failed on device wlp0s29f7u3 ; Operation not permitted.
[bneelka@localhost ~]$ sudo iwconfig wlp0s29f7u4 power off
Error for wireless request "Set Power Management" (8B2C) :
    SET failed on device wlp0s29f7u4 ; Operation not supported.


I am assuming my wireless interfaces are wlp0s29f7u3 and wlp0s29f7u4, but I get a "Operation not permitted".

Any help?

Thanks,
Balaji.

[pnbalaji]

This is solved now. I am using a WiFi adapter that is based on Realtek RTL8192cu chipset which requires special steps to install a "patched" driver.

It appears that I missed to include a command in my forum post https://forums.mageia.org/en/viewtopic.php?f=8&t=9956#p57509 to install the driver.

Below is the code that is missed out as I did not see a file 8192cu-disable-power-management-conf in /etc/modprobe.d.

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sudo cp ./rtl8192cu-fixes/8192cu-disable-power-management.conf /etc/modprobe.d/

.

I copied this file yesterday and now my WiFi signal seems to be much better when waking up the PC from hibernate.

I will mark this thread as SOLVED and also edit my original post to include this step. Oddly, this power management issue seems to be affecting the WiFi signal only when the PC comes up online from hibernate. On reboot, it does not happen.

Thanks,
Balaji.

[doktor5000]

Just for reference, what does that /etc/modprobe.d/8192cu-disable-power-management.conf contain?

[pnbalaji]

Contents of the file are below.

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# Disable power management in the 8192cu driver. This works around a bug in
# some hardware where the device never wakes back up.
# Credit goes to Saqib Razaq (https://github.com/s-razaq) for the fix.

# rtw_power_mgnt=0 disables power saving
# rtw_enusbss=0 disables USB autosuspend
options 8192cu rtw_power_mgnt=0 rtw_enusbss=0


Thanks,
Balaji.