I have upgrade to debian 9 (from debian 8) and since then my system freezes when making traffic with wireless (for example browsing or watching youtube) and I have to turn off the PC. Kernel is:
4.9.0-5-amd64 #1 SMP Debian 4.9.65-3+deb9u2 (2018-01-04) x86_64 GNU/Linux
My desktop PC has a TPLINK TL-WN851ND wireless card which results using ath9k kernel module:
lspci -k 04:06.0 Network controller: Qualcomm Atheros AR9227 Wireless Network Adapter (rev 01) Subsystem: Qualcomm Atheros AR9227 Wireless Network Adapter Kernel driver in use: ath9k Kernel modules: ath9k
If I turn off NetworkManager, my pc never freezes.
When NetworkManager is on, after some minutes (variable), my system freezes.