I compiled a build from master for my r7800 and tplink c2600 but I don't know why but for the first time, I just have r7800 at the end (img, bin) and for c2600 only tplink_c2600-initramfs-uImage is there in bin folder...
thank you for that, I can't use it cause the experimental features needs to be enabled to check the testing kernel and usually during complation we need to press enter for new usb features and with your way to do make and compile I don't receive that in the terminal but I see it in the log, still in waiting.
see last line.
et/sched/Kconfig:45: warning: menuconfig statement without prompt
*
* Restart config...
*
*
* USB Serial Converter support
*
USB Serial Converter support (USB_SERIAL) [M/n/y/?] m
USB Generic Serial Driver (USB_SERIAL_GENERIC) [Y/n/?] y
USB Serial Simple Driver (USB_SERIAL_SIMPLE) [N/m/?] n
USB AIRcable Bluetooth Dongle Driver (USB_SERIAL_AIRCABLE) [N/m/?] n
USB ARK Micro 3116 USB Serial Driver (USB_SERIAL_ARK3116) [N/m/?] n
USB Belkin and Peracom Single Port Serial Driver (USB_SERIAL_BELKIN) [N/m/?] n
USB Winchiphead CH341 Single Port Serial Driver (USB_SERIAL_CH341) [N/m/?] n
USB ConnectTech WhiteHEAT Serial Driver (USB_SERIAL_WHITEHEAT) [N/m/?] n
USB Digi International AccelePort USB Serial Driver (USB_SERIAL_DIGI_ACCELEPORT) [N/m/?] n
USB CP210x family of UART Bridge Controllers (USB_SERIAL_CP210X) [N/m/?] n
USB Cypress M8 USB Serial Driver (USB_SERIAL_CYPRESS_M8) [N/m/?] n
USB Empeg empeg-car Mark I/II Driver (USB_SERIAL_EMPEG) [N/m/?] n
USB FTDI Single Port Serial Driver (USB_SERIAL_FTDI_SIO) [N/m/?] n
USB Handspring Visor / Palm m50x / Sony Clie Driver (USB_SERIAL_VISOR) [N/m/?] n
USB PocketPC PDA Driver (USB_SERIAL_IPAQ) [N/m/?] n
USB IR Dongle Serial Driver (USB_SERIAL_IR) [N/m/?] n
USB Inside Out Edgeport Serial Driver (USB_SERIAL_EDGEPORT) [N/m/?] n
USB Inside Out Edgeport Serial Driver (TI devices) (USB_SERIAL_EDGEPORT_TI) [N/m/?] n
USB Fintek F81232 Single Port Serial Driver (USB_SERIAL_F81232) [N/m/?] n
USB Fintek F81532/534 Multi-Ports Serial Driver (USB_SERIAL_F8153X) [N/m/?] n
USB Garmin GPS driver (USB_SERIAL_GARMIN) [N/m/?] n
USB IPWireless (3G UMTS TDD) Driver (USB_SERIAL_IPW) [N/m/?] n
USB Infinity USB Unlimited Phoenix Driver (USB_SERIAL_IUU) [N/m/?] n
USB Keyspan PDA / Xircom Single Port Serial Driver (USB_SERIAL_KEYSPAN_PDA) [N/m/?] n
USB Keyspan USA-xxx Serial Driver (USB_SERIAL_KEYSPAN) [N/m/?] n
USB KL5KUSB105 (Palmconnect) Driver (USB_SERIAL_KLSI) [N/m/?] n
USB KOBIL chipcard reader (USB_SERIAL_KOBIL_SCT) [N/m/?] n
USB MCT Single Port Serial Driver (USB_SERIAL_MCT_U232) [N/m/?] n
USB Metrologic Instruments USB-POS Barcode Scanner Driver (USB_SERIAL_METRO) [N/m/?] n
USB Moschip 7720 Serial Driver (USB_SERIAL_MOS7720) [N/m/?] n
USB Moschip 7840/7820 USB Serial Driver (USB_SERIAL_MOS7840) [N/m/?] n
USB Moxa UPORT Serial Driver (USB_SERIAL_MXUPORT) [N/m/?] n
USB Navman GPS device (USB_SERIAL_NAVMAN) [N/m/?] n
USB Prolific 2303 Single Port Serial Driver (USB_SERIAL_PL2303) [N/m/?] n
USB Ours Technology Inc. OTi-6858 USB To RS232 Bridge Controller (USB_SERIAL_OTI6858) [N/m/?] n
USB Qualcomm Auxiliary Serial Port Driver (USB_SERIAL_QCAUX) [N/m/?] n
USB Qualcomm Serial modem (USB_SERIAL_QUALCOMM) [N/m/?] n
USB SPCP8x5 USB To Serial Driver (USB_SERIAL_SPCP8X5) [N/m/?] n
USB Safe Serial (Encapsulated) Driver (USB_SERIAL_SAFE) [N/m/?] n
USB Sierra Wireless Driver (USB_SERIAL_SIERRAWIRELESS) [N/m/?] n
USB Symbol Barcode driver (serial mode) (USB_SERIAL_SYMBOL) [N/m/?] n
USB TI 3410/5052 Serial Driver (USB_SERIAL_TI) [N/m/?] n
USB REINER SCT cyberJack pinpad/e-com chipcard reader (USB_SERIAL_CYBERJACK) [N/m/?] n
USB driver for GSM and CDMA modems (USB_SERIAL_OPTION) [N/m/?] n
USB ZyXEL omni.net LCD Plus Driver (USB_SERIAL_OMNINET) [N/m/?] n
USB Opticon Barcode driver (serial mode) (USB_SERIAL_OPTICON) [N/m/?] n
Xsens motion tracker serial interface driver (USB_SERIAL_XSENS_MT) [N/m/?] n
USB-Wishbone adapter interface driver (USB_SERIAL_WISHBONE) [N/m/?] n
USB Quatech SSU-100 Single Port Serial Driver (USB_SERIAL_SSU100) [N/m/?] n
USB Quatech Serial Driver for USB 2 devices (USB_SERIAL_QT2) [N/m/?] n
USB Renesas uPD78F0730 Single Port Serial Driver (USB_SERIAL_UPD78F0730) [N/m/?] n
USB MaxLinear/Exar USB to Serial driver (USB_SERIAL_XR) [N/m/?] (NEW) [ ${PIPESTATUS[0]} -ne 0 ] && exit 1
USB MaxLinear/Exar USB to Serial driver (USB_SERIAL_XR) [N/m/?] (NEW)
No idea, why R7800 gets built, but the other model does not.
Possibly something about the device specific package selections, but that sounds a bit strange.
Other possibility is that you have not done a make clean before the build.
(I do always, so that everything gets built on the same run.)