XPS 13 9360 Wifi Problems Ubuntu 16.04.3 LTS QCA6174 WLP58S0

Hi,

Since new, I've had the following problems with wifi: (XPS 13 9360 QCA6174 wlp58s0)

1. Signal strength is poor compared to other devices. Need to be much closer to the access point.

2. Poor performance, packet loss observed in wireshark. This sometimes results in an inability to authenticate with the access point. Though till now I've assumed this to be caused by issue 1.

3. Occasional (~1 in 20) cold boots or resume from suspend results in no wifi throughput at all. Kernel logs don't reveal any significant warnings or errors. The simplest fix is to suspend the laptop and wake it up again, or power cycle. Rebooting often doesn't resolve the issue. I was once able to resurrect the wifi by unloading and reloading the ath10k_pci kernel module.

4. Occasional drop out under heavy load. This is rare but when the wifi adaptor is in its locked up state it is sometimes possible to authenticate. Sometimes possible to resolve a DNS after several attempts. TCP isn't viable in this state. I was once able to resurrect the adaptor by reloading the kernel module.

There is one thing that confuses me a little. During boot the kernel complains that it cannot find the adapter firmware. This message has always been logged since new. Usually when this type of warning is generated, the associated hardware will be dead until the correct firmware is loaded. Since the adaptor does appear to be functional, I assume that the BIOS must be loading the firmware into the adapter.

With BIOS updates, things did improve initially as when I first bought the machine, it was not possible to suspend/resume without the wifi adapter disappearing from the PCI bus entirely. So we are moving in the right direction.

Just wondering if anyone has any experience of these problems?

Thanks in advance.

--

Craig