Compile error kernel >= 4.19.0-4-amd64

[waveletlet]

On master branch. Using the kernel packages from the Debian repo. Still works with 4.19.0-2-amd64 (4.19.16-1). Here's the output of make -C /lib/modules/$KERNEL/build M=$(pwd) modules with 4.19.0-4-amd64 (4.19.28-2):

Problem still exists after update to 4.19.0-5-amd64 (4.19.37-3).

make: Entering directory '/usr/src/linux-headers-4.19.0-4-amd64'
  CLEAN   /mnt/older/home/user/problems/atheros_problems/atheros/.tmp_versions
  CLEAN   /mnt/older/home/user/problems/atheros_problems/atheros/Module.symvers
make: Leaving directory '/usr/src/linux-headers-4.19.0-4-amd64'
make: Entering directory '/usr/src/linux-headers-4.19.0-4-amd64'
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ar5523/ar5523.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath10k/mac.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath10k/debug.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath10k/core.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath10k/htc.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath10k/htt.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath10k/htt_rx.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath10k/htt_tx.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath10k/txrx.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath10k/wmi.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath10k/wmi-tlv.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath10k/bmi.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath10k/hw.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath10k/p2p.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath10k/swap.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath10k/thermal.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath10k/wow.o
  LD [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath10k/ath10k_core.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath10k/pci.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath10k/ce.o
  LD [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath10k/ath10k_pci.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath10k/usb.o
  LD [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath10k/ath10k_usb.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath5k/caps.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath5k/initvals.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath5k/eeprom.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath5k/gpio.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath5k/desc.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath5k/dma.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath5k/qcu.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath5k/pcu.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath5k/phy.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath5k/reset.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath5k/attach.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath5k/base.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath5k/led.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath5k/rfkill.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath5k/ani.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath5k/sysfs.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath5k/mac80211-ops.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath5k/pci.o
  LD [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath5k/ath5k.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath6kl/debug.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath6kl/hif.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath6kl/htc_mbox.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath6kl/htc_pipe.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath6kl/bmi.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath6kl/cfg80211.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath6kl/init.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath6kl/main.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath6kl/txrx.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath6kl/wmi.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath6kl/core.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath6kl/recovery.o
  LD [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath6kl/ath6kl_core.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath6kl/sdio.o
  LD [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath6kl/ath6kl_sdio.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath6kl/usb.o
  LD [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath6kl/ath6kl_usb.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath9k/beacon.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath9k/gpio.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath9k/init.o
  CC [M]  /mnt/older/home/user/problems/atheros_problems/atheros/ath9k/main.o
/mnt/older/home/user/problems/atheros_problems/atheros/ath9k/main.c: In function ‘ath9k_fill_chanctx_ops’:
/mnt/older/home/user/problems/atheros_problems/atheros/ath9k/main.c:2635:37: error: assignment to ‘void (*)(struct ieee80211_hw *, struct ieee80211_vif *, u16)’ {aka ‘void (*)(struct ieee80211_hw *, struct ieee80211_vif *, short unsigned int)’} from incompatible pointer type ‘void (*)(struct ieee80211_hw *, struct ieee80211_vif *)’ [-Werror=incompatible-pointer-types]
  ath9k_ops.mgd_prepare_tx           = ath9k_mgd_prepare_tx;
                                     ^
cc1: some warnings being treated as errors
make[4]: *** [/usr/src/linux-headers-4.19.0-4-common/scripts/Makefile.build:309: /mnt/older/home/user/problems/atheros_problems/atheros/ath9k/main.o] Error 1
make[3]: *** [/usr/src/linux-headers-4.19.0-4-common/scripts/Makefile.build:549: /mnt/older/home/user/problems/atheros_problems/atheros/ath9k] Error 2
make[2]: *** [/usr/src/linux-headers-4.19.0-4-common/Makefile:1535: _module_/mnt/older/home/user/problems/atheros_problems/atheros] Error 2
make[1]: *** [Makefile:146: sub-make] Error 2
make: *** [Makefile:8: all] Error 2
make: Leaving directory '/usr/src/linux-headers-4.19.0-4-amd64'

[kirvedx]

I've merged your pull requests, so we seem to have this figured out up-to-and-including the kernels available in buster-backports (#5, #6)