[U-Boot] [PATCH] spi: prevent overriding established bus settings

[U-Boot] [PATCH] spi: prevent overriding established bus settings

[Marcin Wojtas]

The SPI stack relies on a proper bus speed/mode configuration
by calling dm_spi_claim_bus(). However the hitherto code
allowed to accidentally override those settings in
the spi_get_bus_and_cs() routine.

The initially established speed could be discarded by using
the slave platdata, which turned out to be an issue on
the platforms whose slave maximum supported frequency
is not on par with the maximum frequency of the bus controller.

This patch fixes above issue by configuring the bus from
spi_get_bus_and_cs() only in case it was not done before.

Signed-off-by: Marcin Wojtas <mw@semihalf.com>
---
 drivers/spi/spi-uclass.c | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/drivers/spi/spi-uclass.c b/drivers/spi/spi-uclass.c
index 76c4b53..fcbe532 100644
--- a/drivers/spi/spi-uclass.c
+++ b/drivers/spi/spi-uclass.c
@@ -296,6 +296,7 @@ int spi_get_bus_and_cs(int busnum, int cs, int speed, int mode,
 {
 	struct udevice *bus, *dev;
 	struct dm_spi_slave_platdata *plat;
+	struct spi_slave *slave;
 	bool created = false;
 	int ret;
 
@@ -351,19 +352,20 @@ int spi_get_bus_and_cs(int busnum, int cs, int speed, int mode,
 		slave->dev = dev;
 	}
 
-	plat = dev_get_parent_platdata(dev);
+	slave = dev_get_parent_priv(dev);
 
-	/* get speed and mode from platdata when available */
-	if (plat->max_hz) {
-		speed = plat->max_hz;
-		mode = plat->mode;
+	/*
+	 * In case the operation speed is not yet established by
+	 * dm_spi_claim_bus() ensure the bus is configured properly.
+	 */
+	if (!slave->speed) {
+		ret = spi_claim_bus(slave);
+		if (ret)
+			goto err;
 	}
-	ret = spi_set_speed_mode(bus, speed, mode);
-	if (ret)
-		goto err;
 
 	*busp = bus;
-	*devp = dev_get_parent_priv(dev);
+	*devp = slave;
 	debug("%s: bus=%p, slave=%p\n", __func__, bus, *devp);
 
 	return 0;
-- 
2.7.4

[U-Boot] [PATCH] spi: prevent overriding established bus settings

[Marcin Wojtas]

+ Simon

czw., 21 lis 2019 o 05:39 Marcin Wojtas <mw@semihalf.com> napisał(a):

> The SPI stack relies on a proper bus speed/mode configuration
> by calling dm_spi_claim_bus(). However the hitherto code
> allowed to accidentally override those settings in
> the spi_get_bus_and_cs() routine.
>
> The initially established speed could be discarded by using
> the slave platdata, which turned out to be an issue on
> the platforms whose slave maximum supported frequency
> is not on par with the maximum frequency of the bus controller.
>
> This patch fixes above issue by configuring the bus from
> spi_get_bus_and_cs() only in case it was not done before.
>
> Signed-off-by: Marcin Wojtas <mw@semihalf.com>
> ---
>  drivers/spi/spi-uclass.c | 20 +++++++++++---------
>  1 file changed, 11 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/spi/spi-uclass.c b/drivers/spi/spi-uclass.c
> index 76c4b53..fcbe532 100644
> --- a/drivers/spi/spi-uclass.c
> +++ b/drivers/spi/spi-uclass.c
> @@ -296,6 +296,7 @@ int spi_get_bus_and_cs(int busnum, int cs, int speed,
> int mode,
>  {
>         struct udevice *bus, *dev;
>         struct dm_spi_slave_platdata *plat;
> +       struct spi_slave *slave;
>         bool created = false;
>         int ret;
>
> @@ -351,19 +352,20 @@ int spi_get_bus_and_cs(int busnum, int cs, int
> speed, int mode,
>                 slave->dev = dev;
>         }
>
> -       plat = dev_get_parent_platdata(dev);
> +       slave = dev_get_parent_priv(dev);
>
> -       /* get speed and mode from platdata when available */
> -       if (plat->max_hz) {
> -               speed = plat->max_hz;
> -               mode = plat->mode;
> +       /*
> +        * In case the operation speed is not yet established by
> +        * dm_spi_claim_bus() ensure the bus is configured properly.
> +        */
> +       if (!slave->speed) {
> +               ret = spi_claim_bus(slave);
> +               if (ret)
> +                       goto err;
>         }
> -       ret = spi_set_speed_mode(bus, speed, mode);
> -       if (ret)
> -               goto err;
>
>         *busp = bus;
> -       *devp = dev_get_parent_priv(dev);
> +       *devp = slave;
>         debug("%s: bus=%p, slave=%p\n", __func__, bus, *devp);
>
>         return 0;
> --
> 2.7.4
>
>

[PATCH] spi: prevent overriding established bus settings

[Marcin Wojtas]

Hi,

Any comments on the patch?

Best regards,
Marcin

czw., 21 lis 2019 o 10:29 Marcin Wojtas <mw@semihalf.com> napisał(a):

> + Simon
>
> czw., 21 lis 2019 o 05:39 Marcin Wojtas <mw@semihalf.com> napisał(a):
>
>> The SPI stack relies on a proper bus speed/mode configuration
>> by calling dm_spi_claim_bus(). However the hitherto code
>> allowed to accidentally override those settings in
>> the spi_get_bus_and_cs() routine.
>>
>> The initially established speed could be discarded by using
>> the slave platdata, which turned out to be an issue on
>> the platforms whose slave maximum supported frequency
>> is not on par with the maximum frequency of the bus controller.
>>
>> This patch fixes above issue by configuring the bus from
>> spi_get_bus_and_cs() only in case it was not done before.
>>
>> Signed-off-by: Marcin Wojtas <mw@semihalf.com>
>> ---
>>  drivers/spi/spi-uclass.c | 20 +++++++++++---------
>>  1 file changed, 11 insertions(+), 9 deletions(-)
>>
>> diff --git a/drivers/spi/spi-uclass.c b/drivers/spi/spi-uclass.c
>> index 76c4b53..fcbe532 100644
>> --- a/drivers/spi/spi-uclass.c
>> +++ b/drivers/spi/spi-uclass.c
>> @@ -296,6 +296,7 @@ int spi_get_bus_and_cs(int busnum, int cs, int speed,
>> int mode,
>>  {
>>         struct udevice *bus, *dev;
>>         struct dm_spi_slave_platdata *plat;
>> +       struct spi_slave *slave;
>>         bool created = false;
>>         int ret;
>>
>> @@ -351,19 +352,20 @@ int spi_get_bus_and_cs(int busnum, int cs, int
>> speed, int mode,
>>                 slave->dev = dev;
>>         }
>>
>> -       plat = dev_get_parent_platdata(dev);
>> +       slave = dev_get_parent_priv(dev);
>>
>> -       /* get speed and mode from platdata when available */
>> -       if (plat->max_hz) {
>> -               speed = plat->max_hz;
>> -               mode = plat->mode;
>> +       /*
>> +        * In case the operation speed is not yet established by
>> +        * dm_spi_claim_bus() ensure the bus is configured properly.
>> +        */
>> +       if (!slave->speed) {
>> +               ret = spi_claim_bus(slave);
>> +               if (ret)
>> +                       goto err;
>>         }
>> -       ret = spi_set_speed_mode(bus, speed, mode);
>> -       if (ret)
>> -               goto err;
>>
>>         *busp = bus;
>> -       *devp = dev_get_parent_priv(dev);
>> +       *devp = slave;
>>         debug("%s: bus=%p, slave=%p\n", __func__, bus, *devp);
>>
>>         return 0;
>> --
>> 2.7.4
>>
>>

[U-Boot] [PATCH] spi: prevent overriding established bus settings

[Simon Glass]

On Thu, 21 Nov 2019 at 04:45, Marcin Wojtas <mw@semihalf.com> wrote:
>
> The SPI stack relies on a proper bus speed/mode configuration
> by calling dm_spi_claim_bus(). However the hitherto code
> allowed to accidentally override those settings in
> the spi_get_bus_and_cs() routine.
>
> The initially established speed could be discarded by using
> the slave platdata, which turned out to be an issue on
> the platforms whose slave maximum supported frequency
> is not on par with the maximum frequency of the bus controller.
>
> This patch fixes above issue by configuring the bus from
> spi_get_bus_and_cs() only in case it was not done before.
>
> Signed-off-by: Marcin Wojtas <mw@semihalf.com>
> ---
>  drivers/spi/spi-uclass.c | 20 +++++++++++---------
>  1 file changed, 11 insertions(+), 9 deletions(-)

Reviewed-by: Simon Glass <sjg@chromium.org>

[U-Boot] [PATCH] spi: prevent overriding established bus settings

[Marcin Wojtas]

Hi Jagan,

sob., 28 gru 2019 o 03:27 Simon Glass <sjg@chromium.org> napisał(a):
>
> On Thu, 21 Nov 2019 at 04:45, Marcin Wojtas <mw@semihalf.com> wrote:
> >
> > The SPI stack relies on a proper bus speed/mode configuration
> > by calling dm_spi_claim_bus(). However the hitherto code
> > allowed to accidentally override those settings in
> > the spi_get_bus_and_cs() routine.
> >
> > The initially established speed could be discarded by using
> > the slave platdata, which turned out to be an issue on
> > the platforms whose slave maximum supported frequency
> > is not on par with the maximum frequency of the bus controller.
> >
> > This patch fixes above issue by configuring the bus from
> > spi_get_bus_and_cs() only in case it was not done before.
> >
> > Signed-off-by: Marcin Wojtas <mw@semihalf.com>
> > ---
> >  drivers/spi/spi-uclass.c | 20 +++++++++++---------
> >  1 file changed, 11 insertions(+), 9 deletions(-)
>
> Reviewed-by: Simon Glass <sjg@chromium.org>

Is there a chance to merge the patch, or do you have any objections?

Best regards,
Marcin

[PATCH] spi: prevent overriding established bus settings

[Jagan Teki]

On Thu, Nov 21, 2019 at 10:09 AM Marcin Wojtas <mw@semihalf.com> wrote:
>
> The SPI stack relies on a proper bus speed/mode configuration
> by calling dm_spi_claim_bus(). However the hitherto code
> allowed to accidentally override those settings in
> the spi_get_bus_and_cs() routine.
>
> The initially established speed could be discarded by using
> the slave platdata, which turned out to be an issue on
> the platforms whose slave maximum supported frequency
> is not on par with the maximum frequency of the bus controller.
>
> This patch fixes above issue by configuring the bus from
> spi_get_bus_and_cs() only in case it was not done before.
>
> Signed-off-by: Marcin Wojtas <mw@semihalf.com>
> ---

Applied to u-boot-spi/master

[PATCH] spi: prevent overriding established bus settings

[Marcin Wojtas]

niedz., 26 sty 2020 o 14:30 Jagan Teki <jagan@amarulasolutions.com> napisał(a):
>
> On Thu, Nov 21, 2019 at 10:09 AM Marcin Wojtas <mw@semihalf.com> wrote:
> >
> > The SPI stack relies on a proper bus speed/mode configuration
> > by calling dm_spi_claim_bus(). However the hitherto code
> > allowed to accidentally override those settings in
> > the spi_get_bus_and_cs() routine.
> >
> > The initially established speed could be discarded by using
> > the slave platdata, which turned out to be an issue on
> > the platforms whose slave maximum supported frequency
> > is not on par with the maximum frequency of the bus controller.
> >
> > This patch fixes above issue by configuring the bus from
> > spi_get_bus_and_cs() only in case it was not done before.
> >
> > Signed-off-by: Marcin Wojtas <mw@semihalf.com>
> > ---
>
> Applied to u-boot-spi/master

Great, thanks!
Marcin