gpio-xx(sysfs) status -16

Hi all,

I am working on the beagleboard xM using the Debian release 7.3 Wheezy , and still using the old non DT Kernel Version 3.9.11-x5.
I have instantiated the PCA9535 in the board file (old method) attached to the I2C2 BUs @400KHz, I have noticed that I cannot export correctly the upper byte (bit 8 to bit 15) while everything works well for the lower ones.
Here the DMESG info I got while trying to toggle some IO from the Kernel User Space using the sysf I/O debugger tools:

[1629753.042938] export_store: status -16
[1629753.043273] _gpio_request: gpio-233 (sysfs) status -16
[1629753.043304] export_store: status -16
[1629753.043609] _gpio_request: gpio-234 (sysfs) status -16
[1629753.043701] export_store: status -16
[1629753.044097] _gpio_request: gpio-235 (sysfs) status -16
[1629753.044128] export_store: status -16
[1629753.044464] _gpio_request: gpio-236 (sysfs) status -16
[1629753.044494] export_store: status -16
[1629753.045013] _gpio_request: gpio-237 (sysfs) status -16

any idea why I am getting such a message and why I always getting cat /sys/class/gpio/gpioXX/ value : 0 while the IO is set as output and echo “1” > /sys/class/gpio/gpioxx/export is set.

I cannot decrypt this Kernel Message and I don’t know from where to start digging.

the cat /sys/kernel/debug/gio tool shows the following:
GPIOs 232-247, i2c/2-0022, pca9535, can sleep:
gpio-232 (sysfs ) out lo
gpio-233 (sysfs ) out lo
gpio-234 (sysfs ) out lo
gpio-235 (sysfs ) out lo
gpio-236 (sysfs ) out lo
gpio-237 (sysfs ) out lo
gpio-238 (sysfs ) out lo
gpio-239 (sysfs ) out lo
gpio-240 (sysfs ) out lo
gpio-241 (sysfs ) out lo
gpio-242 (sysfs ) out lo
gpio-243 (sysfs ) out lo
gpio-244 (sysfs ) out lo
gpio-245 (sysfs ) out lo
gpio-246 (sysfs ) out lo
gpio-247 (sysfs ) out lo

Thanks for any help!

Problem solved with new Kernel from 4.1.x