[PATCH v3] reset: mchp: sparx5: Fix for lan966x

[PATCH v3] reset: mchp: sparx5: Fix for lan966x

[Horatiu Vultur]

With the blamed commit it seems that lan966x doesn't seem to boot
anymore when the internal CPU is used.
The reason seems to be the usage of the devm_of_iomap, if we replace
this with of_iomap, this seems to fix the issue as we use the same
region also for other devices.

Fixes: 0426a920d6269c ("reset: mchp: sparx5: Map cpu-syscon locally in case of LAN966x")
Reviewed-by: Herve Codina <herve.codina@bootlin.com>
Tested-by: Herve Codina <herve.codina@bootlin.com>
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
---
v2->v3:
- forward error from of_address_to_resource
- use devm_ioremap instead of_iomap
v1->v2:
- make sure to use iounmap when driver is removed
---
 drivers/reset/reset-microchip-sparx5.c | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/drivers/reset/reset-microchip-sparx5.c b/drivers/reset/reset-microchip-sparx5.c
index aa5464be7053b..176b3f46e9243 100644
--- a/drivers/reset/reset-microchip-sparx5.c
+++ b/drivers/reset/reset-microchip-sparx5.c
@@ -8,6 +8,7 @@
  */
 #include <linux/mfd/syscon.h>
 #include <linux/of.h>
+#include <linux/of_address.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/property.h>
@@ -72,14 +73,19 @@ static struct regmap *mchp_lan966x_syscon_to_regmap(struct device *dev,
 						    struct device_node *syscon_np)
 {
 	struct regmap_config regmap_config = mchp_lan966x_syscon_regmap_config;
-	resource_size_t size;
+	struct resource res;
 	void __iomem *base;
+	int err;
+
+	err = of_address_to_resource(syscon_np, 0, &res);
+	if (err)
+		return ERR_PTR(err);
 
-	base = devm_of_iomap(dev, syscon_np, 0, &size);
-	if (IS_ERR(base))
-		return ERR_CAST(base);
+	base = devm_ioremap(dev, res.start, resource_size(&res));
+	if (!base)
+		return ERR_PTR(-ENOMEM);
 
-	regmap_config.max_register = size - 4;
+	regmap_config.max_register =  resource_size(&res) - 4;
 
 	return devm_regmap_init_mmio(dev, base, &regmap_config);
 }
-- 
2.34.1

Re: [PATCH v3] reset: mchp: sparx5: Fix for lan966x

[Philipp Zabel]

On Mi, 2025-02-26 at 15:46 +0100, Horatiu Vultur wrote:
> With the blamed commit it seems that lan966x doesn't seem to boot
> anymore when the internal CPU is used.
> The reason seems to be the usage of the devm_of_iomap, if we replace
> this with of_iomap, this seems to fix the issue as we use the same
            ^^^^^^^^
The is not accurate anymore.

> region also for other devices.
> 
> Fixes: 0426a920d6269c ("reset: mchp: sparx5: Map cpu-syscon locally in case of LAN966x")
> Reviewed-by: Herve Codina <herve.codina@bootlin.com>
> Tested-by: Herve Codina <herve.codina@bootlin.com>

Is this still correct?

> Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
> ---
> v2->v3:
> - forward error from of_address_to_resource
> - use devm_ioremap instead of_iomap
> v1->v2:
> - make sure to use iounmap when driver is removed
> ---
>  drivers/reset/reset-microchip-sparx5.c | 16 +++++++++++-----
>  1 file changed, 11 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/reset/reset-microchip-sparx5.c b/drivers/reset/reset-microchip-sparx5.c
> index aa5464be7053b..176b3f46e9243 100644
> --- a/drivers/reset/reset-microchip-sparx5.c
> +++ b/drivers/reset/reset-microchip-sparx5.c
> @@ -8,6 +8,7 @@
>   */
>  #include <linux/mfd/syscon.h>
>  #include <linux/of.h>
> +#include <linux/of_address.h>
>  #include <linux/module.h>
>  #include <linux/platform_device.h>
>  #include <linux/property.h>
> @@ -72,14 +73,19 @@ static struct regmap *mchp_lan966x_syscon_to_regmap(struct device *dev,
>  						    struct device_node *syscon_np)
>  {
>  	struct regmap_config regmap_config = mchp_lan966x_syscon_regmap_config;
> -	resource_size_t size;
> +	struct resource res;
>  	void __iomem *base;
> +	int err;
> +
> +	err = of_address_to_resource(syscon_np, 0, &res);
> +	if (err)
> +		return ERR_PTR(err);
>  
> -	base = devm_of_iomap(dev, syscon_np, 0, &size);
> -	if (IS_ERR(base))
> -		return ERR_CAST(base);

It would be nice to add a comment here that devm_of_iomap() can't be
used because the resource is shared with other devices. Do you know
which ones?

Otherwise, this looks good to me.


regards
Philipp

Re: [PATCH v3] reset: mchp: sparx5: Fix for lan966x

[Herve Codina]

Hi Philipp, Horatiu,

On Wed, 26 Feb 2025 17:32:22 +0100
Philipp Zabel <p.zabel@pengutronix.de> wrote:

...

> > Fixes: 0426a920d6269c ("reset: mchp: sparx5: Map cpu-syscon locally in case of LAN966x")
> > Reviewed-by: Herve Codina <herve.codina@bootlin.com>
> > Tested-by: Herve Codina <herve.codina@bootlin.com>  
> 
> Is this still correct?

Yes, it is correct.

Reviewed this v3, saw Philipp's comments and I have nothing more to add.

Also tested this v3 and no regression were detected.

Best regards,
Hervé

Re: [PATCH v3] reset: mchp: sparx5: Fix for lan966x

[Philipp Zabel]

On Mi, 2025-02-26 at 18:24 +0100, Herve Codina wrote:
> Hi Philipp, Horatiu,
> 
> On Wed, 26 Feb 2025 17:32:22 +0100
> Philipp Zabel <p.zabel@pengutronix.de> wrote:
> 
> ...
> 
> > > Fixes: 0426a920d6269c ("reset: mchp: sparx5: Map cpu-syscon locally in case of LAN966x")
> > > Reviewed-by: Herve Codina <herve.codina@bootlin.com>
> > > Tested-by: Herve Codina <herve.codina@bootlin.com>  
> > 
> > Is this still correct?
> 
> Yes, it is correct.
> 
> Reviewed this v3, saw Philipp's comments and I have nothing more to add.
> 
> Also tested this v3 and no regression were detected.

Excellent, thank you.

regards
Philipp

Re: [PATCH v3] reset: mchp: sparx5: Fix for lan966x

[Horatiu Vultur]

The 02/26/2025 17:32, Philipp Zabel wrote:

Hi,

> 
> On Mi, 2025-02-26 at 15:46 +0100, Horatiu Vultur wrote:
> > With the blamed commit it seems that lan966x doesn't seem to boot
> > anymore when the internal CPU is used.
> > The reason seems to be the usage of the devm_of_iomap, if we replace
> > this with of_iomap, this seems to fix the issue as we use the same
>             ^^^^^^^^
> The is not accurate anymore.

Good catch. I will update in the next version.

> 
> > region also for other devices.
> >
> > Fixes: 0426a920d6269c ("reset: mchp: sparx5: Map cpu-syscon locally in case of LAN966x")
> > Reviewed-by: Herve Codina <herve.codina@bootlin.com>
> > Tested-by: Herve Codina <herve.codina@bootlin.com>
> 
> Is this still correct?
> 
> > Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
> > ---
> > v2->v3:
> > - forward error from of_address_to_resource
> > - use devm_ioremap instead of_iomap
> > v1->v2:
> > - make sure to use iounmap when driver is removed
> > ---
> >  drivers/reset/reset-microchip-sparx5.c | 16 +++++++++++-----
> >  1 file changed, 11 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/reset/reset-microchip-sparx5.c b/drivers/reset/reset-microchip-sparx5.c
> > index aa5464be7053b..176b3f46e9243 100644
> > --- a/drivers/reset/reset-microchip-sparx5.c
> > +++ b/drivers/reset/reset-microchip-sparx5.c
> > @@ -8,6 +8,7 @@
> >   */
> >  #include <linux/mfd/syscon.h>
> >  #include <linux/of.h>
> > +#include <linux/of_address.h>
> >  #include <linux/module.h>
> >  #include <linux/platform_device.h>
> >  #include <linux/property.h>
> > @@ -72,14 +73,19 @@ static struct regmap *mchp_lan966x_syscon_to_regmap(struct device *dev,
> >                                                   struct device_node *syscon_np)
> >  {
> >       struct regmap_config regmap_config = mchp_lan966x_syscon_regmap_config;
> > -     resource_size_t size;
> > +     struct resource res;
> >       void __iomem *base;
> > +     int err;
> > +
> > +     err = of_address_to_resource(syscon_np, 0, &res);
> > +     if (err)
> > +             return ERR_PTR(err);
> >
> > -     base = devm_of_iomap(dev, syscon_np, 0, &size);
> > -     if (IS_ERR(base))
> > -             return ERR_CAST(base);
> 
> It would be nice to add a comment here that devm_of_iomap() can't be
> used because the resource is shared with other devices. Do you know
> which ones?

Yes, I will add a comment in the next version.
Looking at the device trees (lan966x.dtsi), it looks like it is shared
with the clock driver (clks).

> 
> Otherwise, this looks good to me.
> 
> 
> regards
> Philipp

-- 
/Horatiu