The two guesses I would have are, something with the SE Linux policy not letting the system server at /sys/class stuff if you are on a device that enforcing policy, and I'd expect to be able to find some indication using the instructions at:
https://source.android.com/devices/tech/security/selinux/validate.html and the next guess would be that the GUI is running in some chrooted sandbox that doesn't include /sys/class (possibly new behavior with one of the secondary user configuration.) I'd explore that with some walk through the / file system code in the GUI and see what you can see from that context compared to "adb shell". On Tuesday, December 23, 2014 9:39:36 AM UTC-5, Hubert CHAUMETTE wrote: > > Hi, > > I am working on enabling the backlight brightness tuning through the GUI > on an AM437xevm. The sysfs file > /sys/class/backlight/backlight.10/brightness can be used to adjust the > brightness through the shell, but the GUI fails to open this file, despite > it being RW and owned by system: > > ls -l /sys/class/backlight/backlight.10/brightness > -rw-r--r-- system system 4096 2000-01-01 00:00 brightness > > The failure appears in logcat: > > I/lights ( 2163): write_int failed to open /sys/class/backlight/backlight > .10/brightness > > Furthermore, PID 2163 (system_server) is run as the system user: > > # ps 2163 > USER PID PPID VSIZE RSS WCHAN PC NAME > system 2163 1433 580812 43188 ffffffff 400d77cc S system_server > > What can be the issue? > -- -- unsubscribe: [email protected] website: http://groups.google.com/group/android-porting --- You received this message because you are subscribed to the Google Groups "android-porting" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
