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Date: Tue, 9 Aug 2011 19:16:30 -0700
From: Greg KH <greg@kroah.com>
To: "Murali K. Vemuri" <vemuri.muralikrishna@gmail.com>
Cc: Ryan Mallon <rmallon@gmail.com>, linux-kernel@vger.kernel.org
Subject: Re: kernel panic with simple driver
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On Wed, Aug 10, 2011 at 10:33:28AM +0900, Murali K. Vemuri wrote:
> There is no concurrent access to the timer. The design is that:
> 1.Driver provides an IOCTL for start / stop
> 2. when the driver receives START IOCTL, it toggles some GPIOs to ON / OFF.
> 3. the GPIOs will be ON for 500 MSec and OFF for 500 MSec.
> 4. Two successive START IOCTLs will not be honored.
> 5. There is only one application that uses these IOCTLs
> 6. When I receive a STOP IOCTL, I am doing :
> if (timer_pending (&my_timer))
> del_timer(&my_timer);

What kind of driver is this?  For what type of hardware?

Can't you control the gpios from userspace with out any need to write a
kernel driver?

thanks,

greg k-h