Gfilui

I have a notebook with QCA6174 802.11ac Wireless Network Adapter. Initially it doesn't work on ubuntu 16.04.

I've copied this firmware files:

https://github.com/kvalo/ath10k-firmware/tree/master/QCA6174

into /lib/firmware/ath10k.

I've also renamed file /lib/firmware/ath10k/QCA6174/hw3.0/firmware-4.bin_WLAN.RM.2.0-00180-QCARMSWPZ-1 to firmware-4.bin
and /lib/firmware/ath10k/QCA6174/hw2.1/firmware-5.bin_SW_RM.1.1.1-00157-QCARMSWPZ-1 to firmware-5.bin.

Now network-manager see wifi adapter and connects. It works fine but after a while internet stops working.

There are no error messages in journalctl -ru NetworkManager.service in this moment.

And wi-fi works again after sudo service network-manager restart

This is my iwconfig:

wlp2s0 IEEE 802.11 ESSID:"MyWiFi" 
 Mode:Managed Frequency:2.412 GHz Access Point: D4:6E:0E:51:3F:AE 
 Bit Rate=1 Mb/s Tx-Power=20 dBm 
 Retry short limit:7 RTS thr:off Fragment thr:off
 Power Management:on
 Link Quality=52/70 Signal level=-58 dBm 
 Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
 Tx excessive retries:0 Invalid misc:41 Missed beacon:0

enp7s0 no wireless extensions.

lo no wireless extensions.

And lshw -class network

 *-network 
 description: Wireless interface
 product: QCA6174 802.11ac Wireless Network Adapter
 vendor: Qualcomm Atheros
 physical id: 0
 bus info: pci@0000:02:00.0
 logical name: wlp2s0
 version: 32
 serial: 58:00:e3:f6:bd:6f
 width: 64 bits
 clock: 33MHz
 capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
 configuration: broadcast=yes driver=ath10k_pci driverversion=4.13.0-36-generic firmware=WLAN.RM.4.4.1-00051-QCARMSWP-1 ip=192.168.0.104 latency=0 link=yes multicast=yes wireless=IEEE 802.11
 resources: irq:320 memory:94000000-941fffff

What could be the problem?

It works fine but after a while internet stops working.

Please try disabling power saving in Network Manager. From the terminal:

sudo sed -i 's/3/2/' /etc/NetworkManager/conf.d/*
sudo service network-manager restart

Any improvement?

EDIT: Be certain that you have the latest possible firmware. Please open a terminal and do:

cd /tmp
wget http://mirrors.kernel.org/ubuntu/pool/main/l/linux-firmware/linux-firmware_1.169.3_all.deb
sudo dpkg -i linux*.deb

Reboot and tell us if there is any improvement.