The ath79 flash driver (src/flash/nor/ath79) expects the "offset" argument to the ath79_read and ath79_write functions to be CPU addresses (which need to be adjusted by subtracting "bank->base" from them).
But, the core flash driver already subtracts "bank->base", so the ath79 flash read/write functions fail. I believe an older version of the core code passed the CPU address (and let the driver subtract bank->base), but this is no longer the case.
I've attached a patch to fix this. I've tested on a QCA9550-based ath79 platform.
Paul, can you please submit your patch to http://openocd.zylin.com/
See http://openocd.org/doc/doxygen/html/patchguide.html for detials.
Thanks
Fixed in http://openocd.zylin.com/#/c/4821/1