Linux 6.5 Continues Making Preparations For WiFi 7, Enabling New Hardware

The Linux 6.5 networking subsystem changes include more preparations around the ongoing WiFi 7 wireless standard as well as bringing up support for a number of newer network adapters.

Over the past year Intel engineers have been doing a lot for the WiFi 7 support under Linux to benefit their IWLWIFI driver and their forthcoming 802.11be chipsets. A lot of the enablement work has been around WiFi 7's Multi-Link Operation (MLO) mode. WiFi 7 MLO allows devices to simultaneously send and receive data across multiple frequency bands and channels. MLO allows 2.4GHz, 5GHz, and 6GHz bands to all be simultaneously used with supported hardware. With Linux 6.5, more Multi-Link Operation code is now in place.

The Intel WiFi driver in Linux 6.5 has also seen a "major update" for dealing with new device firmware and enabling MLO mode. The IWLWIFI driver can also now support segmented PNVM images and power tables as well as a new Platform Antenna Gain (PPAG) feature.

Some of the other WiFi happenings for this new kernel include the Qualcomm 802.11ax "ath11k" driver adding Multiple Basic Service Set Identifier (MBSSID) support and Enhanced MBSSID Advertisement (EMA) in the AP mode. A factory test mode feature has also been added to the ath11k driver. The Realtek RTW89 driver meanwhile adds RSSI-based antenna diversity and support for U-NII-4 channels on the 6GHz band. Lastly the Realtek RTL8XXXU driver has added AP mode support and support for USB-RX aggregation with newer USB chipsets.

Some of the new network hardware support in Linux 6.5 includes the Realtek RTL8192FU, 2.4 GHz, b/g/n mode, 2T2R, 300 Mbps, Realtek RTL8723DS (SDIO variant), and Realtek RTL8851BE when it comes to wireless ASICs. New wired hardware support in Linux 6.5 includes the Synopsys EMAC4, Marvell 88E6361 8 port (5x1GE + 3x2.5GE) switches, Marvell 88E6250 7 port switches, Microchip LAN8650/1 Rev.B0 PHYs, and MediaTek MT7981/MT7988 built-in 1GE PHY.

The usually-huge Linux 6.5 networking subsystem update also brings numerous BPF additions, dynamic interrupt allocation for the Intel 100G driver, active scanning in IEEE 802.15.4, per-VMA locking for page-flipping TCP receive zero-copy handling, support for auto-generating a user-space C library for various Netlink families, socket busy polling for CONFIG_RT, and reworking the sendpage and splice implementations. More details on the many networking updates in Linux 6.5 via this Git merge.