Re: [U-Boot] [Patch V5 2/4] spi: fsl_qspi: Fix qspi_op_rdid memcpy issue

[Qianyu Gong]

> -----Original Message-----
> From: Scott Wood
> Sent: Friday, January 22, 2016 3:30 AM
> To: Qianyu Gong <qianyu.g...@nxp.com>; u-boot@lists.denx.de;
> r58...@freescale.com
> Cc: mingkai...@freescale.com; jt...@openedev.com; b48...@freescale.com;
> shaohui....@freescale.com; wenbin.s...@freescale.com; Scott Wood
> <o...@buserror.net>; Gong Qianyu <qianyu.g...@freescale.com>
> Subject: Re: [Patch V5 2/4] spi: fsl_qspi: Fix qspi_op_rdid memcpy issue
> 
> On 01/20/2016 09:43 PM, Gong Qianyu wrote:
> > From: Gong Qianyu <qianyu.g...@freescale.com>
> >
> > In current driver everytime we memcpy 4 bytes to the dest memory
> > regardless of the remaining length.
> > This patch adds checking the remaining length before memcpy.
> > If the length is shorter than 4 bytes, memcpy the actual length of
> > data to the dest memory.
> >
> > Signed-off-by: Gong Qianyu <qianyu.g...@freescale.com>
> > ---
> > V2-V5:
> >  - No change.
> >
> >  drivers/spi/fsl_qspi.c | 5 ++++-
> >  1 file changed, 4 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/spi/fsl_qspi.c b/drivers/spi/fsl_qspi.c index
> > 38e5900..f178857 100644
> > --- a/drivers/spi/fsl_qspi.c
> > +++ b/drivers/spi/fsl_qspi.c
> > @@ -500,7 +500,10 @@ static void qspi_op_rdid(struct fsl_qspi_priv *priv, 
> > u32
> *rxbuf, u32 len)
> >             if (rbsr_reg & QSPI_RBSR_RDBFL_MASK) {
> >                     data = qspi_read32(priv->flags, &regs->rbdr[i]);
> >                     data = qspi_endian_xchg(data);
> > -                   memcpy(rxbuf, &data, 4);
> > +                   if (size < 4)
> > +                           memcpy(rxbuf, &data, size);
> > +                   else
> > +                           memcpy(rxbuf, &data, 4);
> 
> memcpy(rxbuf, &data, min(size, 4));
> 
> >                     rxbuf++;
> >                     size -= 4;
> >                     i++;
> 
> size -= 4 even if size was < 4?
> 
> -Scott

Yes.. The following is complete code:

        i = 0;
        size = len;
        while ((RX_BUFFER_SIZE >= size) && (size > 0)) {
                rbsr_reg = qspi_read32(priv->flags, &regs->rbsr);
                if (rbsr_reg & QSPI_RBSR_RDBFL_MASK) {
                        data = qspi_read32(priv->flags, &regs->rbdr[i]);
                        data = qspi_endian_xchg(data);
                        memcpy(rxbuf, &data, min(size, 4));
                        rxbuf++;
                        size -= 4;
                        i++;
                }
        }


Regards,
Qianyu
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