Comment 114 for bug 1521173

my investigation came to same conclusion as #109 (but I'm on 20.04 and latest kernel, so this is still relevant)

My configuration is as follows.
It there is a need to get more information/logs, please let me know.
--

Dell Latitude 7389
miki@DL-7389:~$ cat /etc/lsb-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=20.04
DISTRIB_CODENAME=focal
DISTRIB_DESCRIPTION="Ubuntu 20.04 LTS"
miki@DL-7389:~$ uname -a
Linux DL-7389 5.4.0-31-generic #35-Ubuntu SMP Thu May 7 20:20:34 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

dmesg gets spammed by these error reports:
[116522.584941] pcieport 0000:00:1c.0: AER: Corrected error received: 0000:00:1c.0
[116522.584959] pcieport 0000:00:1c.0: AER: PCIe Bus Error: severity=Corrected, type=Data Link Layer, (Transmitter ID)
[116522.584967] pcieport 0000:00:1c.0: AER: device [8086:9d17] error status/mask=00001000/00002000
[116522.584973] pcieport 0000:00:1c.0: AER: [12] Timeout
[116533.643718] pcieport 0000:00:1c.0: AER: Corrected error received: 0000:00:1c.0
[116533.643735] pcieport 0000:00:1c.0: AER: PCIe Bus Error: severity=Corrected, type=Data Link Layer, (Transmitter ID)
[116533.643744] pcieport 0000:00:1c.0: AER: device [8086:9d17] error status/mask=00001000/00002000
[116533.643751] pcieport 0000:00:1c.0: AER: [12] Timeout
[116559.755644] pcieport 0000:00:1c.0: AER: Corrected error received: 0000:00:1c.0
[116559.755655] pcieport 0000:00:1c.0: AER: PCIe Bus Error: severity=Corrected, type=Data Link Layer, (Transmitter ID)
[116559.755658] pcieport 0000:00:1c.0: AER: device [8086:9d17] error status/mask=00001000/00002000
[116559.755660] pcieport 0000:00:1c.0: AER: [12] Timeout

Device causing it seems to be Qualcomm Atheros QCA6174 802.11ac Wireless Network Adapter:

miki@DL-7389:~$ sudo lspci -t -v
-[0000:00]-+-00.0 Intel Corporation Xeon E3-1200 v6/7th Gen Core Processor Host Bridge/DRAM Registers
           +-02.0 Intel Corporation HD Graphics 620
           +-04.0 Intel Corporation Xeon E3-1200 v5/E3-1500 v5/6th Gen Core Processor Thermal Subsystem
           +-13.0 Intel Corporation Sunrise Point-LP Integrated Sensor Hub
           +-14.0 Intel Corporation Sunrise Point-LP USB 3.0 xHCI Controller
           +-14.2 Intel Corporation Sunrise Point-LP Thermal subsystem
           +-15.0 Intel Corporation Sunrise Point-LP Serial IO I2C Controller #0
           +-15.1 Intel Corporation Sunrise Point-LP Serial IO I2C Controller #1
           +-15.2 Intel Corporation Sunrise Point-LP Serial IO I2C Controller #2
           +-16.0 Intel Corporation Sunrise Point-LP CSME HECI #1
           +-1c.0-[01]----00.0 Qualcomm Atheros QCA6174 802.11ac Wireless Network Adapter
           +-1d.0-[02]----00.0 Toshiba Corporation Device 0116
           +-1f.0 Intel Corporation Sunrise Point LPC Controller/eSPI Controller
           +-1f.2 Intel Corporation Sunrise Point-LP PMC
           +-1f.3 Intel Corporation Sunrise Point-LP HD Audio
           \-1f.4 Intel Corporation Sunrise Point-LP SMBus

lspci -v detailed output for this device (strange that the serial number is read as zeros):

01:00.0 Network controller: Qualcomm Atheros QCA6174 802.11ac Wireless Network Adapter (rev 32)
        Subsystem: Dell QCA6174 802.11ac Wireless Network Adapter
        Flags: bus master, fast devsel, latency 0, IRQ 145
        Memory at ef000000 (64-bit, non-prefetchable) [size=2M]
        Capabilities: [40] Power Management version 3
        Capabilities: [50] MSI: Enable+ Count=1/8 Maskable+ 64bit-
        Capabilities: [70] Express Endpoint, MSI 00
        Capabilities: [100] Advanced Error Reporting
        Capabilities: [148] Virtual Channel
        Capabilities: [168] Device Serial Number 00-00-00-00-00-00-00-00
        Capabilities: [178] Latency Tolerance Reporting
        Capabilities: [180] L1 PM Substates
        Kernel driver in use: ath10k_pci
        Kernel modules: ath10k_pci

lshw output for this device (here the serial number is visible correctly, I redacted):

        *-pci:0
             description: PCI bridge
             product: Sunrise Point-LP PCI Express Root Port #8
             vendor: Intel Corporation
             physical id: 1c
             bus info: pci@0000:00:1c.0
             version: f1
             width: 32 bits
             clock: 33MHz
             capabilities: pci pciexpress msi pm normal_decode bus_master cap_list
             configuration: driver=pcieport
             resources: irq:122 memory:ef000000-ef1fffff
           *-network
                description: Wireless interface
                product: QCA6174 802.11ac Wireless Network Adapter
                vendor: Qualcomm Atheros
                physical id: 0
                bus info: pci@0000:01:00.0
                logical name: wlp1s0
                version: 32
                serial: ------redacted------
                width: 64 bits
                clock: 33MHz
                capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
                configuration: broadcast=yes driver=ath10k_pci driverversion=5.4.0-31-generic firmware=WLAN.RM.4.4.1-00140-QCARMSWPZ-1 ip=192.168.0.58 latency=0 link=yes multicast=yes wireless=IEEE 802.11
                resources: irq:145 memory:ef000000-ef1fffff