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

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

[Yunhui Cui]

From: Yunhui Cui <yunhui.cui@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@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;
 
 	/* 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);
-- 
2.1.0.27.g96db324

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

[Prabhakar Kushwaha]

> -----Original Message-----
> From: U-Boot [mailto:u-boot-bounces at lists.denx.de] On Behalf Of Yunhui Cui
> Sent: Tuesday, July 12, 2016 8:20 AM
> To: york sun <york.sun@nxp.com>
> Cc: Yunhui Cui <yunhui.cui@nxp.com>; u-boot at lists.denx.de
> Subject: [U-Boot] [PATCH v3] driver: spi: fsl-qspi: disable AHB buffer prefetch
> 
> From: Yunhui Cui <yunhui.cui@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.
> 

Can we add slightly more details about workaround other than Just enabling CONFIG_SYS_FSL_QSPI_AHB.
With this you can avoid details of workaround in code. 

Please add CONFIG_SYS_FSL_QSPI_AHB in README file

> Signed-off-by: Yunhui Cui <yunhui.cui@nxp.com>
> ---

Patch revision history missing.

--prabhakar

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

[york sun]

On 07/11/2016 08:00 PM, Yunhui Cui wrote:
> From: Yunhui Cui <yunhui.cui@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@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


>
>   	/* 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);
>

[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@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@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);
> >

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

[york sun]

On 07/12/2016 07:24 PM, Yunhui Cui wrote:
>
> On 07/12/2016 11:15 PM, York wrote:
>> On 07/11/2016 08:00 PM, Yunhui Cui wrote:
>>> From: Yunhui Cui <yunhui.cui@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@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.

OK. That's fine.

York

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

[york sun]

On 07/11/2016 08:00 PM, Yunhui Cui wrote:
> From: Yunhui Cui <yunhui.cui@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@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;
>
>  	/* 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.
> +	*/

Please fix the multi-line comment style, and address Prabhakar's comment.

York

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

[Yunhui Cui]

On Tuesday, July 12, 2016 11:06 AM Prabhakar Wrote
> 
> > -----Original Message-----
> > From: U-Boot [mailto:u-boot-bounces at lists.denx.de] On Behalf Of Yunhui
> > Cui
> > Sent: Tuesday, July 12, 2016 8:20 AM
> > To: york sun <york.sun@nxp.com>
> > Cc: Yunhui Cui <yunhui.cui@nxp.com>; u-boot at lists.denx.de
> > Subject: [U-Boot] [PATCH v3] driver: spi: fsl-qspi: disable AHB buffer
> > prefetch
> >
> > From: Yunhui Cui <yunhui.cui@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.
> >
> 
> Can we add slightly more details about workaround other than Just
> enabling CONFIG_SYS_FSL_QSPI_AHB.
> With this you can avoid details of workaround in code.
> 
[Yunhui] ok!

> Please add CONFIG_SYS_FSL_QSPI_AHB in README file

[Yunhui] why should we add it and how to add it ?

> 
> > Signed-off-by: Yunhui Cui <yunhui.cui@nxp.com>
> > ---
> 
> Patch revision history missing.
> 
> --prabhakar