[PATCH 00/10] carl9170: 802.11n compliance and driver improvements

[Masi Osmani <mas-i@hotmail.de>]

The carl9170 driver for Atheros AR9170-based USB WiFi adapters has been
effectively unmaintained since 2016.  While the hardware shipped as
Draft-N certified, several 802.11n capabilities were never advertised
to mac80211, diagnostic counters were left as TODO stubs, and some
hardware features were never wired up.

This series addresses these gaps in 10 independent patches, ordered
from simple HT capability flags to more involved PHY programming:

Patches 1-3: HT capability corrections
  - Enable SGI_20 (was only SGI_40)
  - Advertise RX STBC (1 spatial stream)
  - Document the SMPS handler (replacing bare TODO)

Patches 4-5: Diagnostic counters
  - Wire up the RX dropped frame counter
  - Track PHY errors via debugfs

Patch 6: TX power calibration
  - Replace hardcoded 18 dBm with per-channel EEPROM values

Patch 7: Recovery hardening
  - Add exponential backoff to prevent restart storms

Patch 8: Antenna diversity
  - Enable fast antenna diversity for 2-chain devices

Patch 9: DFS radar detection
  - Program radar registers, call ieee80211_radar_detected()

Patch 10: Runtime IQ calibration
  - Periodic I/Q recalibration via existing stat_work timer

All patches are individually compile-tested and have been verified
on real hardware (AVM Fritz!WLAN USB Stick N, AR9001U) running
kernel 6.18.12.  Each patch applies and compiles independently on
top of the previous ones.

The ath9k PCI driver for the same chipset family serves as the
primary reference for register programming and capability flags.

Masi Osmani (10):
  carl9170: mac80211: enable Short Guard Interval for 20 MHz
  carl9170: mac80211: advertise RX STBC capability
  carl9170: mac80211: document spatial multiplexing power save handler
  carl9170: rx: wire up dropped frame counter
  carl9170: rx: track PHY errors via debugfs
  carl9170: phy: populate per-channel TX power from EEPROM
  carl9170: main: add exponential restart backoff
  carl9170: phy: enable antenna diversity for 2-chain devices
  carl9170: fw: enable DFS radar detection
  carl9170: phy: add periodic runtime IQ calibration

 drivers/net/wireless/ath/carl9170/carl9170.h |   5 +
 drivers/net/wireless/ath/carl9170/debug.c    |   2 +
 drivers/net/wireless/ath/carl9170/fw.c       |   3 +
 drivers/net/wireless/ath/carl9170/main.c     |  45 ++++-
 drivers/net/wireless/ath/carl9170/phy.c      | 194 +++++++++++++++++++
 drivers/net/wireless/ath/carl9170/rx.c       |  23 ++-
 6 files changed, 261 insertions(+), 11 deletions(-)

--
2.51.0