Documentation for PWMIOC_SETCHARACTERISTICS ioctl command mentioned
that this command will neither start nor stop the pulsed output. This
however is incorrect as PWMIOC_SETCHARACTERISTICS command leads to
pwm_start() function which starts the pulsed output.
While this might not be the correct behaviour (I would probably welcome
the option to set PWM characteristics without starting the pulsed output)
it is the way the PWM driver is coded for many architectures. Future
enhancement might be to add function pwm_setchar() for example to just
set characteristics without starting the PWM output.
Signed-off-by: Michal Lenc <michallenc@seznam.cz>
Resolution of Issue 619 will require multiple steps, this part of the first step in that resolution: Every call to nxsem_wait_uninterruptible() must handle the return value from nxsem_wait_uninterruptible properly. This commit is only for rwbuffer.c and those files under drivers/serial, drivers/timers, and drivers/usbdev.
This commit completes that step for all of the files under drivers/. Still remaining: All of the files under arch/.
* Simplify EINTR/ECANCEL error handling
1. Add semaphore uninterruptible wait function
2 .Replace semaphore wait loop with a single uninterruptible wait
3. Replace all sem_xxx to nxsem_xxx
* Unify the void cast usage
1. Remove void cast for function because many place ignore the returned value witout cast
2. Replace void cast for variable with UNUSED macro
