Patch 1/2: The deprecated and obsoleted - but still used (especially in older releases) /sys/class/gpio interface allows modifying GPIOs which are excluded by the "valid_mask". This makes the valid_mask not suitable for cases where toggling GPIO can cause damage. Patch adds validity check to export. I assume many people are still using the /sys/class/gpio at least for testing purposes - especially with older releases. Thus it might be worth the hassle to exclude invalid GPIOs - they're probably set invalid for a good reason. (Actually, I noticed this when trying to use the valid_mask to invalidate undocumented GPO on BD71815 - which may be connected to GND. The people using BD71815 are likely to be using some stable-release, which probably supports the (deprected, obsolete) sysfs until the end of the days => valid_mask is not safe way unless fix to this is backported to stable). Patch 2/2: checkpatch nowadays reminds us that ENOTSUPP is not valid error and should be replaced by EOPNOTSUPP. It'd be nice if GPIO drivers could return also the EOPNOTSUPP from config and avoid being nagged by checkpatch. Matti Vaittinen (2): gpio: sysfs: Obey valid_mask gpiolib: Allow drivers to return EOPNOTSUPP from config drivers/gpio/gpiolib-sysfs.c | 8 ++++++++ drivers/gpio/gpiolib.c | 2 +- 2 files changed, 9 insertions(+), 1 deletion(-) -- 2.25.4 -- Matti Vaittinen, Linux device drivers ROHM Semiconductors, Finland SWDC Kiviharjunlenkki 1E 90220 OULU FINLAND ~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~ Simon says - in Latin please. ~~~ "non cogito me" dixit Rene Descarte, deinde evanescavit ~~~ Thanks to Simon Glass for the translation =]