Re: [PATCH] OMAP: UART: Keep the TX fifo full when possible

From: Greg KH
Date: Tue Aug 27 2013 - 19:01:34 EST


On Tue, Aug 20, 2013 at 08:57:25AM -0700, Kevin Hilman wrote:
> + Felipe
>
> On Mon, Jul 8, 2013 at 3:04 AM, Alexander Savchenko
> <oleksandr.savchenko@xxxxxx> wrote:
> > From: Dmitry Fink <finik@xxxxxx>
> >
> > Current logic results in interrupt storm since the fifo
> > is constantly below the threshold level. Change the logic
> > to fill all the available spaces in the fifo as long as
> > we have data to minimize the possibilty of underflow and
> > elimiate excessive interrupts.
> >
> > Signed-off-by: Dmitry Fink <finik@xxxxxx>
> > Signed-off-by: Alexander Savchenko <oleksandr.savchenko@xxxxxx>
>
> Hmm, another OMAP serial patch that wasn't Cc'd to linux-omap where
> OMAP users might have seen it. :(
>
> I just bisected a strange problem in linux-next on OMAP3 down to this
> patch. Reverting it fixes the problem.
>
> On OMAP3530 Beagle and Overo, after boot, doing a 'cat /proc/cpuinfo'
> was not returning to a prompt, suggesting something strange with the
> FIFO. Hitting return gets me back to a prompt.
>
> Greg, this one should also be dropped from tty-next until it can be
> further investgated and the problem solved.

Now reverted, thanks.

greg k-h
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