Ticket #2279 (new defect)
toggling backlight very fast blocks reads of /proc/apm
|Reported by:||lindi||Owned by:||openmoko-kernel|
|Severity:||minor||Keywords:||kernel backlight DoS|
|Blocking:||Estimated Completion (week):|
Steps to reproduce:
1) Start "while cat /proc/apm; do sleep 1; done" in one terminal
while true; do
echo 255 > /sys/class/backlight/gta02-bl/brightness
echo 15 > /sys/class/backlight/gta02-bl/brightness
in another terminal
2) backlight brightness changes very fast but cat is still sometimes scheduled and can read from /proc/apm
2) backlight brightness changes very fast but the read() to /proc/apm never returns.
1) I was just trying to make freerunner work as a strobe light when I noticed that I could not stop the program. This probably happened because Xorg was stuck reading from some file and would never succeed.
2) I am using andy-tracking 9ecc089861ab238e