Re: [PATCH 3/7] serial: imx: init dma_is_{rx|tx}ing variables

From: Uwe Kleine-König
Date: Mon Jul 03 2017 - 02:53:03 EST


On Fri, Jun 30, 2017 at 02:13:29PM +0200, Lothar Waßmann wrote:
> Hi,
>
> On Fri, 30 Jun 2017 14:04:42 +0200 Romain Perier wrote:
> > From: Nandor Han <nandor.han@xxxxxx>
> >
> > Initialize both dma_is_{rx|tx}ing variables when DMA is enabled to avoid
> > checking uninitialized variables if port shutdown is requested before
> > DMA channels get a chance to start.
> >
> > Signed-off-by: Nandor Han <nandor.han@xxxxxx>
> > Signed-off-by: Romain Perier <romain.perier@xxxxxxxxxxxxx>
> > ---
> > drivers/tty/serial/imx.c | 3 +++
> > 1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
> > index 188063d..81fb413 100644
> > --- a/drivers/tty/serial/imx.c
> > +++ b/drivers/tty/serial/imx.c
> > @@ -1225,6 +1225,9 @@ static void imx_enable_dma(struct imx_port *sport)
> >
> > imx_setup_ufcr(sport, TXTL_DMA, RXTL_DMA);
> >
> > + sport->dma_is_rxing = 0;
> > + sport->dma_is_txing = 0;
> > +
> > sport->dma_is_enabled = 1;
> > }
> >
> sport is devm_kzalloc()ed, so the variables are initialized to 0 anyway.

I'd agree to Lothar's statement. Did you find this issue by inspection,
or does it fix a compiler warning? Do you think there is an actual
problem?

Best regards
Uwe

--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | http://www.pengutronix.de/ |