On Thu, Apr 2, 2009 at 5:36 AM, Peter Teoh <htmldeveloper@xxxxxxxxx> wrote:
> i think u are right, looking at drivers/char/rocket.c as an example
> (read the comment):
>
Yes, with drivers write entry point this is fine......but what about
using it with workqueue context?
> /*
> * Exception handler - write routine, called when user app writes to
> the device.
> * A per port write mutex is used to protect from another process writing to
> * this port at the same time. This other process could be running
> on the other CPU
> * or get control of the CPU if the copy_from_user() blocks due to a
> page fault (swapped out).
> * Spinlocks protect the info xmit members.
> */
> static int rp_write(struct tty_struct *tty,
> const unsigned char *buf, int count)
> {
> struct r_port *info = tty->driver_data;
> CHANNEL_t *cp;
> const unsigned char *b;
> int c, retval = 0;
> unsigned long flags;
>
> if (count <= 0 || rocket_paranoia_check(info, "rp_write"))
> return 0;
>
> if (mutex_lock_interruptible(&info->write_mtx))
> return -ERESTARTSYS;
>
>
> On Wed, Apr 1, 2009 at 11:12 PM, Devesh Sharma <devesh28@xxxxxxxxx> wrote:
>> Hello list,
>>
>> Consider a case where I have a workqueue, a work is submitted to a it
>> from some interrupt handler
>> Lets say, some where in a code, it tries to get some semaphore to
>> enter into a critical section,
>> and fails to get it, sholud I still return from the work function by
>> returning ERESTARTSYS?
>> Kindly somebody clarify this to me
>>
>> Thanks in advance
>> Devesh
>>
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>>
>
>
>
> --
> Regards,
> Peter Teoh
>
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