From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maxime Ripard Date: Fri, 14 Dec 2018 10:25:22 +0100 Subject: [U-Boot] [PATCH 1/1] arm: sunxi: Add NULL pointer check In-Reply-To: <449750de-5be4-aeb1-9d5c-43b42f175ce0@olimex.com> References: <20181205122757.14523-1-stefan@olimex.com> <20181205154619.ffzfl7yt6vfo3qra@flea> <9458ed1f-38de-6be0-8e27-a2d6801492a2@gmail.com> <449750de-5be4-aeb1-9d5c-43b42f175ce0@olimex.com> Message-ID: <20181214092522.3ev2b4d4q33k6zip@flea> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit To: u-boot@lists.denx.de On Thu, Dec 13, 2018 at 09:12:57AM +0200, Stefan Mavrodiev wrote: > > On 12/6/18 8:41 AM, Stefan Mavrodiev wrote: > > > > On 12/5/18 5:46 PM, Maxime Ripard wrote: > > > On Wed, Dec 05, 2018 at 02:27:57PM +0200, Stefan Mavrodiev wrote: > > > > Current driver doesn't check if the destination pointer is NULL. > > > > This cause the data from the FIFO to be stored inside the internal > > > > SDRAM ( address 0 ). > > > > > > > > The patch add simple check if the destination pointer is NULL. > > > > > > > > Signed-off-by: Stefan Mavrodiev > > > > --- > > > >   drivers/spi/sun4i_spi.c | 3 ++- > > > >   1 file changed, 2 insertions(+), 1 deletion(-) > > > > > > > > diff --git a/drivers/spi/sun4i_spi.c b/drivers/spi/sun4i_spi.c > > > > index b86b5a00ad..38cc743c61 100644 > > > > --- a/drivers/spi/sun4i_spi.c > > > > +++ b/drivers/spi/sun4i_spi.c > > > > @@ -129,7 +129,8 @@ static inline void > > > > sun4i_spi_drain_fifo(struct sun4i_spi_priv *priv, int len) > > > >         while (len--) { > > > >           byte = readb(&priv->regs->rxdata); > > > > -        *priv->rx_buf++ = byte; > > > > +        if (priv->rx_buf) > > > > +            *priv->rx_buf++ = byte; > > > It seems pretty inefficient to test the pointer at each access, it > > > would be better to check it once before starting the transfer. > > > > > > I'm not sure if that can even happen? > > > > I've tried to check that before draining the receive fifo, but > > then the controller doesn't work. I'm thinking that the fifo must > > be drained in any case. > > Any further comments? I was expecting you to comment on whether the FIFO needed to be drained or not :) Maxime -- Maxime Ripard, Bootlin Embedded Linux and Kernel engineering https://bootlin.com -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 228 bytes Desc: not available URL: