[U-Boot] Fix read error in fsl_qspi driver

[U-Boot] Fix read error in fsl_qspi driver

[Thomas Schaefer]

Hi all,

The following patchset will fix QSPI flash read error discovered on i.MX7D
Sabre eval system. Could you please check and apply to upcoming v2019.07
release?

Best regards,
Thomas Schaefer

[PATCH 1/2] drivers/spi: fsl_qspi: fix read timeout
[PATCH 2/2] drivers/spi: fsl_qspi: improve timeout calculation

[U-Boot] [PATCH 1/2] drivers/spi: fsl_qspi: fix read timeout

[Thomas Schaefer]

During QSPI reads, current is_controller_busy function sporadically
fails with -ETIMEDOUT due to fixed number of 5 test loops. Using
timer functions to wait 1000 us instead will fix this.

Signed-off-by: Thomas Schaefer <thomas.schaefer@kontron.com>
---
 drivers/spi/fsl_qspi.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/spi/fsl_qspi.c b/drivers/spi/fsl_qspi.c
index 1598c4f698..2c5937509f 100644
--- a/drivers/spi/fsl_qspi.c
+++ b/drivers/spi/fsl_qspi.c
@@ -152,7 +152,7 @@ static inline int is_controller_busy(const struct fsl_qspi_priv *priv)
 	u32 val;
 	const u32 mask = QSPI_SR_BUSY_MASK | QSPI_SR_AHB_ACC_MASK |
 			 QSPI_SR_IP_ACC_MASK;
-	unsigned int retry = 5;
+	unsigned long timeout = timer_get_us() + 1000;
 
 	do {
 		val = qspi_read32(priv->flags, &priv->regs->sr);
@@ -160,10 +160,9 @@ static inline int is_controller_busy(const struct fsl_qspi_priv *priv)
 		if ((~val & mask) == mask)
 			return 0;
 
-		udelay(1);
-	} while (--retry);
-
-	return -ETIMEDOUT;
+		if (timer_get_us() > timeout )
+			return -ETIMEDOUT;
+	} while (1);
 }
 
 /* QSPI support swapping the flash read/write data
-- 
2.11.0

[U-Boot] [PATCH 2/2] drivers/spi: fsl_qspi: improve timeout calculation

[Thomas Schaefer]

Use readl_poll_timeout instead of explicit calculation

Signed-off-by: Thomas Schaefer <thomas.schaefer@kontron.com>
---
 drivers/spi/fsl_qspi.c | 17 ++++++-----------
 1 file changed, 6 insertions(+), 11 deletions(-)

diff --git a/drivers/spi/fsl_qspi.c b/drivers/spi/fsl_qspi.c
index 2c5937509f..41abe1996f 100644
--- a/drivers/spi/fsl_qspi.c
+++ b/drivers/spi/fsl_qspi.c
@@ -10,6 +10,7 @@
 #include <spi.h>
 #include <asm/io.h>
 #include <linux/sizes.h>
+#include <linux/iopoll.h>
 #include <dm.h>
 #include <errno.h>
 #include <watchdog.h>
@@ -150,19 +151,13 @@ static void qspi_write32(u32 flags, u32 *addr, u32 val)
 static inline int is_controller_busy(const struct fsl_qspi_priv *priv)
 {
 	u32 val;
-	const u32 mask = QSPI_SR_BUSY_MASK | QSPI_SR_AHB_ACC_MASK |
-			 QSPI_SR_IP_ACC_MASK;
-	unsigned long timeout = timer_get_us() + 1000;
+	u32 mask = QSPI_SR_BUSY_MASK | QSPI_SR_AHB_ACC_MASK |
+		   QSPI_SR_IP_ACC_MASK;
 
-	do {
-		val = qspi_read32(priv->flags, &priv->regs->sr);
+	if (priv->flags & QSPI_FLAG_REGMAP_ENDIAN_BIG)
+		mask = (u32)cpu_to_be32(mask);
 
-		if ((~val & mask) == mask)
-			return 0;
-
-		if (timer_get_us() > timeout )
-			return -ETIMEDOUT;
-	} while (1);
+	return readl_poll_timeout(&priv->regs->sr, val, !(val & mask), 1000);
 }
 
 /* QSPI support swapping the flash read/write data
-- 
2.11.0

[U-Boot] [PATCH 1/2] drivers/spi: fsl_qspi: fix read timeout

[Fabio Estevam]

On Mon, Jul 1, 2019 at 12:38 PM Thomas Schaefer
<thomas.schaefer@kontron.com> wrote:
>
> During QSPI reads, current is_controller_busy function sporadically
> fails with -ETIMEDOUT due to fixed number of 5 test loops. Using
> timer functions to wait 1000 us instead will fix this.
>
> Signed-off-by: Thomas Schaefer <thomas.schaefer@kontron.com>

Thanks for the fix:

Reviewed-by: Fabio Estevam <festevam@gmail.com>

[U-Boot] [PATCH 2/2] drivers/spi: fsl_qspi: improve timeout calculation

[Fabio Estevam]

On Mon, Jul 1, 2019 at 12:37 PM Thomas Schaefer
<thomas.schaefer@kontron.com> wrote:
>
> Use readl_poll_timeout instead of explicit calculation
>
> Signed-off-by: Thomas Schaefer <thomas.schaefer@kontron.com>

Reviewed-by: Fabio Estevam <festevam@gmail.com>

[U-Boot] [PATCH 1/2] drivers/spi: fsl_qspi: fix read timeout

[Jagan Teki]

On Mon, Jul 1, 2019 at 9:08 PM Thomas Schaefer
<thomas.schaefer@kontron.com> wrote:
>
> During QSPI reads, current is_controller_busy function sporadically
> fails with -ETIMEDOUT due to fixed number of 5 test loops. Using
> timer functions to wait 1000 us instead will fix this.
>
> Signed-off-by: Thomas Schaefer <thomas.schaefer@kontron.com>
> ---

Applied to u-boot-spi/master

[U-Boot] [PATCH 2/2] drivers/spi: fsl_qspi: improve timeout calculation

[Jagan Teki]

On Mon, Jul 1, 2019 at 9:07 PM Thomas Schaefer
<thomas.schaefer@kontron.com> wrote:
>
> Use readl_poll_timeout instead of explicit calculation
>
> Signed-off-by: Thomas Schaefer <thomas.schaefer@kontron.com>
> ---
>  drivers/spi/fsl_qspi.c | 17 ++++++-----------
>  1 file changed, 6 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/spi/fsl_qspi.c b/drivers/spi/fsl_qspi.c
> index 2c5937509f..41abe1996f 100644
> --- a/drivers/spi/fsl_qspi.c
> +++ b/drivers/spi/fsl_qspi.c
> @@ -10,6 +10,7 @@
>  #include <spi.h>
>  #include <asm/io.h>
>  #include <linux/sizes.h>
> +#include <linux/iopoll.h>
>  #include <dm.h>
>  #include <errno.h>
>  #include <watchdog.h>
> @@ -150,19 +151,13 @@ static void qspi_write32(u32 flags, u32 *addr, u32 val)
>  static inline int is_controller_busy(const struct fsl_qspi_priv *priv)
>  {
>         u32 val;
> -       const u32 mask = QSPI_SR_BUSY_MASK | QSPI_SR_AHB_ACC_MASK |
> -                        QSPI_SR_IP_ACC_MASK;
> -       unsigned long timeout = timer_get_us() + 1000;
> +       u32 mask = QSPI_SR_BUSY_MASK | QSPI_SR_AHB_ACC_MASK |
> +                  QSPI_SR_IP_ACC_MASK;
>
> -       do {
> -               val = qspi_read32(priv->flags, &priv->regs->sr);
> +       if (priv->flags & QSPI_FLAG_REGMAP_ENDIAN_BIG)
> +               mask = (u32)cpu_to_be32(mask);

This look like a BE check, which was not there before isn't it?

[U-Boot] [PATCH 2/2] drivers/spi: fsl_qspi: improve timeout calculation

[Thomas Schaefer]

> Von: Jagan Teki <jagan@amarulasolutions.com> 
> Gesendet: Dienstag, 2. Juli 2019 13:12
> 
> On Mon, Jul 1, 2019 at 9:07 PM Thomas Schaefer <thomas.schaefer@kontron.com> wrote:
> >
> > Use readl_poll_timeout instead of explicit calculation
> >
> > Signed-off-by: Thomas Schaefer <thomas.schaefer@kontron.com>
> > ---
> >  drivers/spi/fsl_qspi.c | 17 ++++++-----------
> >  1 file changed, 6 insertions(+), 11 deletions(-)
> >
> > diff --git a/drivers/spi/fsl_qspi.c b/drivers/spi/fsl_qspi.c index 
> > 2c5937509f..41abe1996f 100644
> > --- a/drivers/spi/fsl_qspi.c
> > +++ b/drivers/spi/fsl_qspi.c
> > @@ -10,6 +10,7 @@
> >  #include <spi.h>
> >  #include <asm/io.h>
> >  #include <linux/sizes.h>
> > +#include <linux/iopoll.h>
> >  #include <dm.h>
> >  #include <errno.h>
> >  #include <watchdog.h>
> > @@ -150,19 +151,13 @@ static void qspi_write32(u32 flags, u32 *addr, 
> > u32 val)  static inline int is_controller_busy(const struct 
> > fsl_qspi_priv *priv)  {
> >         u32 val;
> > -       const u32 mask = QSPI_SR_BUSY_MASK | QSPI_SR_AHB_ACC_MASK |
> > -                        QSPI_SR_IP_ACC_MASK;
> > -       unsigned long timeout = timer_get_us() + 1000;
> > +       u32 mask = QSPI_SR_BUSY_MASK | QSPI_SR_AHB_ACC_MASK |
> > +                  QSPI_SR_IP_ACC_MASK;
> >
> > -       do {
> > -               val = qspi_read32(priv->flags, &priv->regs->sr);
> > +       if (priv->flags & QSPI_FLAG_REGMAP_ENDIAN_BIG)
> > +               mask = (u32)cpu_to_be32(mask);
> 
> This look like a BE check, which was not there before isn't it?
> 

Hi Jagan,

The previous implementation was using the qspi_read32 function, that
implemented this endianess checking. As the readl_poll_timeout macro finally
ends with

#define __arch_getl(a)  (*(volatile unsigned int *)(a))

in arch/arm/include/asm/io.h. When swapping the 'mask' in case of BE, the
result is the same as when using qspi_read32 before.

However, I did not test this as the QSPI_FLAG_REGMAP_ENDIAN_BIG is not set
on i.MX7 systems.

Also I found that current linux kernel does this BE check (negated LE check)
with the 'mask' variable in drivers/spi/spi-fsl-qspi.c

if (!q->devtype_data->little_endian)
    mask = (u32)cpu_to_be32(mask);

Best reards,
Thomas

[U-Boot] [PATCH 2/2] drivers/spi: fsl_qspi: improve timeout calculation

[Jagan Teki]

On Tue, Jul 2, 2019 at 5:13 PM Thomas Schaefer
<Thomas.Schaefer@kontron.com> wrote:
>
> > Von: Jagan Teki <jagan@amarulasolutions.com>
> > Gesendet: Dienstag, 2. Juli 2019 13:12
> >
> > On Mon, Jul 1, 2019 at 9:07 PM Thomas Schaefer <thomas.schaefer@kontron.com> wrote:
> > >
> > > Use readl_poll_timeout instead of explicit calculation
> > >
> > > Signed-off-by: Thomas Schaefer <thomas.schaefer@kontron.com>
> > > ---
> > >  drivers/spi/fsl_qspi.c | 17 ++++++-----------
> > >  1 file changed, 6 insertions(+), 11 deletions(-)
> > >
> > > diff --git a/drivers/spi/fsl_qspi.c b/drivers/spi/fsl_qspi.c index
> > > 2c5937509f..41abe1996f 100644
> > > --- a/drivers/spi/fsl_qspi.c
> > > +++ b/drivers/spi/fsl_qspi.c
> > > @@ -10,6 +10,7 @@
> > >  #include <spi.h>
> > >  #include <asm/io.h>
> > >  #include <linux/sizes.h>
> > > +#include <linux/iopoll.h>
> > >  #include <dm.h>
> > >  #include <errno.h>
> > >  #include <watchdog.h>
> > > @@ -150,19 +151,13 @@ static void qspi_write32(u32 flags, u32 *addr,
> > > u32 val)  static inline int is_controller_busy(const struct
> > > fsl_qspi_priv *priv)  {
> > >         u32 val;
> > > -       const u32 mask = QSPI_SR_BUSY_MASK | QSPI_SR_AHB_ACC_MASK |
> > > -                        QSPI_SR_IP_ACC_MASK;
> > > -       unsigned long timeout = timer_get_us() + 1000;
> > > +       u32 mask = QSPI_SR_BUSY_MASK | QSPI_SR_AHB_ACC_MASK |
> > > +                  QSPI_SR_IP_ACC_MASK;
> > >
> > > -       do {
> > > -               val = qspi_read32(priv->flags, &priv->regs->sr);
> > > +       if (priv->flags & QSPI_FLAG_REGMAP_ENDIAN_BIG)
> > > +               mask = (u32)cpu_to_be32(mask);
> >
> > This look like a BE check, which was not there before isn't it?
> >
>
> Hi Jagan,
>
> The previous implementation was using the qspi_read32 function, that
> implemented this endianess checking. As the readl_poll_timeout macro finally
> ends with
>
> #define __arch_getl(a)  (*(volatile unsigned int *)(a))
>
> in arch/arm/include/asm/io.h. When swapping the 'mask' in case of BE, the
> result is the same as when using qspi_read32 before.

Okay, it was supported before. thanks for the clarity.