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From: David Hawkins <dwh@ovro.caltech.edu>
To: Misbah khan <misbah_khan@engineer.com>
Cc: linuxppc-embedded@ozlabs.org
Subject: Re: Problem faced while using workqueue in the character driver.
Date: Fri, 20 Jul 2007 10:18:35 -0700	[thread overview]
Message-ID: <46A0EE6B.3000904@ovro.caltech.edu> (raw)
In-Reply-To: <11705912.post@talk.nabble.com>

Hi Misbah,

> I am working on a character driver for FPGA, in which i am using a blocked
> read call on workqueue. The read call will be unblocked by the Interrupt
> from the Fpga to PPC Cpu.
> 
> The problem is that if the process is in blocked mode and then an Interrupt
> occurs the system gives kernel Panic where as it get unblocked and start
> reading the data but very soon it gets crashed.
> 
> Please send me your suggessins regarding the mentioned problem.

Er, without seeing the code, its a bit difficult to suggest
anything.

Perhaps you are using work-queues incorrectly?

Take a look at:

simple_work_queue.c

In the tar-ball

http://www.ovro.caltech.edu/~dwh/correlator/software/driver_design.tar.gz

Which is described in:

http://www.ovro.caltech.edu/~dwh/correlator/pdf/LNX-723-Hawkins.pdf

There's also a more complex 'COBRA driver' here:

http://www.ovro.caltech.edu/~dwh/correlator/cobra_docs.html

Having an example of a working driver that uses work-queues
might help you.

Dave

  reply	other threads:[~2007-07-20 17:26 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-07-20 10:40 Problem faced while using workqueue in the character driver Misbah khan
2007-07-20 17:18 ` David Hawkins [this message]
2007-07-23  3:35   ` Misbah khan

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