[U-Boot] [PATCH v3] driver: spi: fsl-qspi: disable AHB buffer prefetch

[Yunhui Cui]

On 07/12/2016 11:15 PM, York wrote:
> On 07/11/2016 08:00 PM, Yunhui Cui wrote:
> > From: Yunhui Cui <yunhui.cui at nxp.com>
> >
> > Errata: A-009282: QuadSPI data pre-fetch can result in incorrect data
> > We need this errata workaround when CONFIG_SYS_FSL_QSPI_AHB is enabled.
> >
> > Signed-off-by: Yunhui Cui <yunhui.cui at nxp.com>
> > ---
> >   drivers/spi/fsl_qspi.c | 12 +++++++++++-
> >   1 file changed, 11 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/spi/fsl_qspi.c b/drivers/spi/fsl_qspi.c index
> > 75cbab2..0354e20 100644
> > --- a/drivers/spi/fsl_qspi.c
> > +++ b/drivers/spi/fsl_qspi.c
> > @@ -438,13 +438,23 @@ static void qspi_enable_ddr_mode(struct
> fsl_qspi_priv *priv)
> >   static void qspi_init_ahb_read(struct fsl_qspi_priv *priv)
> >   {
> >   	struct fsl_qspi_regs *regs = priv->regs;
> > +	int rx_size = 0x80;
> 
> Wrap this with ifdef, or you will have compiling warning when the macro
> is not defined.
> 
> York

[Yunhui] Whether This macro defined or not, rx_size will be used, It seems that Wrap is not necessary and have no compiling warning. 

thanks.
Yunhui

	
> 
> 
> >
> >   	/* AHB configuration for access buffer 0/1/2 .*/
> >   	qspi_write32(priv->flags, &regs->buf0cr,
> QSPI_BUFXCR_INVALID_MSTRID);
> >   	qspi_write32(priv->flags, &regs->buf1cr,
> QSPI_BUFXCR_INVALID_MSTRID);
> >   	qspi_write32(priv->flags, &regs->buf2cr,
> > QSPI_BUFXCR_INVALID_MSTRID);
> > +
> > +#ifdef CONFIG_SYS_FSL_ERRATUM_A009282
> > +	/*A-009282: QuadSPI data pre-fetch can result in incorrect data
> > +	 *Workaround: Keep the read data size to 64 bits (8 Bytes), which
> > +	 *disables the prefetch on the AHB buffer,and prevents this issue
> > +	 *from occurring.
> > +	*/
> > +	rx_size = 0x1;
> > +#endif
> >   	qspi_write32(priv->flags, &regs->buf3cr, QSPI_BUF3CR_ALLMST_MASK |
> > -		     (0x80 << QSPI_BUF3CR_ADATSZ_SHIFT));
> > +		     (rx_size << QSPI_BUF3CR_ADATSZ_SHIFT));
> >
> >   	/* We only use the buffer3 */
> >   	qspi_write32(priv->flags, &regs->buf0ind, 0);
> >