[PATCH v6 1/1] PRUSS UIO driver support

TK, Pratheesh Gangadhar pratheesh at ti.com
Mon Feb 28 23:45:27 EST 2011


Hi,

> -----Original Message-----
> From: Hans J. Koch [mailto:hjk at hansjkoch.de]
> Sent: Tuesday, March 01, 2011 2:57 AM
> To: TK, Pratheesh Gangadhar
> Cc: linux-kernel at vger.kernel.org; hjk at hansjkoch.de; gregkh at suse.de;
> tglx at linutronix.de; sshtylyov at mvista.com; arnd at arndb.de; Chatterjee, Amit;
> davinci-linux-open-source at linux.davincidsp.com; linux-arm-
> kernel at lists.infradead.org
> Subject: Re: [PATCH v6 1/1] PRUSS UIO driver support
> 
> On Tue, Mar 01, 2011 at 02:31:35AM +0530, Pratheesh Gangadhar wrote:
> > +
> > +		/* Register PRUSS IRQ lines */
> > +		p->irq = IRQ_DA8XX_EVTOUT0 + cnt;
> > +		p->handler = pruss_handler;
> > +
> > +		ret = uio_register_device(&dev->dev, p);
> > +
> > +		if (ret < 0)
> > +			goto out_free;
> > +	}
> > +
> > +	spin_lock_init(&lock);
> 
> That's too late. uio_register_device() enables the irq, and your spin_lock
> is not ready at that time.

This is ok in this context as "modprobe uio_pruss" is pre-requisite for
running PRUSS firmware and without firmware running PRUSS won't
generate interrupts. Actually PRUSS INTC is not setup till we start
user application.

Thanks,
Pratheesh




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