I have a device driver, I compiled the driver on petalinux-v0.30-rc1. The device driver declares a semaphore using:
Then I use:
down_interruptible(&sem) and up(&sem)
When I build the driver, I see the following warning messages:
Building modules, stage 2.
MODPOST 1 modules
WARNING: “__up” [……/scull.ko] undefined!
WARNING: “__down_interruptible” [……/scull.ko] undefined!
and I cannot do insmod due to the above unknown symbols.
Has anyone used semaphore successfully on microblaze linux before?