[PATCH v4 0/4] soc: ti: Add module build support to the socinfo

[PATCH v4 0/4] soc: ti: Add module build support to the socinfo

[Nicolas Frayer]

In order for the TI K3 SoC info driver to be built as a module, the
following changes have been made:
- Converted memory allocations to devm and added the remove callback
- Added necessary code to build the driver as a module
- UDMA: Added deferred probe when soc_device_match() fails because the
socinfo driver is built as a module and hasn't probed yet
- MDIO: Same as the UDMA driver, return deferred probe if
soc_device_match() returns null

v2->v3:
dropped module conversion part of this series while other driver
dependencies on socinfo are worked out.
A dependency issue is introduced by changing subsys_initcall()
to module_platform_driver(). Some drivers using the socinfo information
probe before the socinfo driver itself and it makes their probe fail.

v3->v4:
reintegrated the module build support and added patches for udma and mdio
drivers to allow for deferred probe if socinfo hasn't probed yet.

Nicolas Frayer (4):
  soc: ti: Convert allocations to devm
  soc: ti: Add module build support
  dmaengine: ti: k3-udma: Deferring probe when soc_device_match()
    returns NULL
  net: ethernet: ti: davinci_mdio: Deferring probe when
    soc_device_match() returns NULL

 arch/arm64/Kconfig.platforms           |  1 -
 drivers/dma/ti/k3-udma.c               |  2 +-
 drivers/net/ethernet/ti/davinci_mdio.c |  4 +++
 drivers/soc/ti/Kconfig                 |  3 +-
 drivers/soc/ti/k3-socinfo.c            | 47 ++++++++++++++++----------
 5 files changed, 37 insertions(+), 20 deletions(-)

-- 
2.25.1

[PATCH v4 1/4] soc: ti: Convert allocations to devm

[Nicolas Frayer]

Changed the memory and resource allocations in the probe function
to devm. Also added a remove callback.

Signed-off-by: Nicolas Frayer <nfrayer@baylibre.com>
---
 drivers/soc/ti/k3-socinfo.c | 36 +++++++++++++++++++-----------------
 1 file changed, 19 insertions(+), 17 deletions(-)

diff --git a/drivers/soc/ti/k3-socinfo.c b/drivers/soc/ti/k3-socinfo.c
index 91f441ee6175..19f3e74f5376 100644
--- a/drivers/soc/ti/k3-socinfo.c
+++ b/drivers/soc/ti/k3-socinfo.c
@@ -96,21 +96,18 @@ static int k3_chipinfo_probe(struct platform_device *pdev)
 	partno_id = (jtag_id & CTRLMMR_WKUP_JTAGID_PARTNO_MASK) >>
 		 CTRLMMR_WKUP_JTAGID_PARTNO_SHIFT;
 
-	soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
+	soc_dev_attr = devm_kzalloc(&pdev->dev, sizeof(*soc_dev_attr), GFP_KERNEL);
 	if (!soc_dev_attr)
 		return -ENOMEM;
 
-	soc_dev_attr->revision = kasprintf(GFP_KERNEL, "SR%x.0", variant);
-	if (!soc_dev_attr->revision) {
-		ret = -ENOMEM;
-		goto err;
-	}
+	soc_dev_attr->revision = devm_kasprintf(&pdev->dev, GFP_KERNEL, "SR%x.0", variant);
+	if (!soc_dev_attr->revision)
+		return -ENOMEM;
 
 	ret = k3_chipinfo_partno_to_names(partno_id, soc_dev_attr);
 	if (ret) {
 		dev_err(dev, "Unknown SoC JTAGID[0x%08X]\n", jtag_id);
-		ret = -ENODEV;
-		goto err_free_rev;
+		return -ENODEV;
 	}
 
 	node = of_find_node_by_path("/");
@@ -118,22 +115,26 @@ static int k3_chipinfo_probe(struct platform_device *pdev)
 	of_node_put(node);
 
 	soc_dev = soc_device_register(soc_dev_attr);
-	if (IS_ERR(soc_dev)) {
-		ret = PTR_ERR(soc_dev);
-		goto err_free_rev;
-	}
+	if (IS_ERR(soc_dev))
+		return PTR_ERR(soc_dev);
+
+	platform_set_drvdata(pdev, soc_dev);
 
 	dev_info(dev, "Family:%s rev:%s JTAGID[0x%08x] Detected\n",
 		 soc_dev_attr->family,
 		 soc_dev_attr->revision, jtag_id);
 
 	return 0;
+}
+
+static int k3_chipinfo_remove(struct platform_device *pdev)
+{
+	struct soc_device *soc_dev = platform_get_drvdata(pdev);
 
-err_free_rev:
-	kfree(soc_dev_attr->revision);
-err:
-	kfree(soc_dev_attr);
-	return ret;
+	if (soc_dev)
+		soc_device_unregister(soc_dev);
+
+	return 0;
 }
 
 static const struct of_device_id k3_chipinfo_of_match[] = {
@@ -147,6 +148,7 @@ static struct platform_driver k3_chipinfo_driver = {
 		.of_match_table = k3_chipinfo_of_match,
 	},
 	.probe = k3_chipinfo_probe,
+	.remove = k3_chipinfo_remove,
 };
 
 static int __init k3_chipinfo_init(void)
-- 
2.25.1

[PATCH v4 2/4] soc: ti: Add module build support

[Nicolas Frayer]

Added module build support for the TI K3 SoC info driver.

Signed-off-by: Nicolas Frayer <nfrayer@baylibre.com>
---
 arch/arm64/Kconfig.platforms |  1 -
 drivers/soc/ti/Kconfig       |  3 ++-
 drivers/soc/ti/k3-socinfo.c  | 11 +++++++++++
 3 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/Kconfig.platforms b/arch/arm64/Kconfig.platforms
index 76580b932e44..4f2f92eb499f 100644
--- a/arch/arm64/Kconfig.platforms
+++ b/arch/arm64/Kconfig.platforms
@@ -130,7 +130,6 @@ config ARCH_K3
 	select TI_SCI_PROTOCOL
 	select TI_SCI_INTR_IRQCHIP
 	select TI_SCI_INTA_IRQCHIP
-	select TI_K3_SOCINFO
 	help
 	  This enables support for Texas Instruments' K3 multicore SoC
 	  architecture.
diff --git a/drivers/soc/ti/Kconfig b/drivers/soc/ti/Kconfig
index 7e2fb1c16af1..1a730c057cce 100644
--- a/drivers/soc/ti/Kconfig
+++ b/drivers/soc/ti/Kconfig
@@ -74,7 +74,8 @@ config TI_K3_RINGACC
 	  If unsure, say N.
 
 config TI_K3_SOCINFO
-	bool
+	tristate "TI K3 SoC info driver"
+	default y
 	depends on ARCH_K3 || COMPILE_TEST
 	select SOC_BUS
 	select MFD_SYSCON
diff --git a/drivers/soc/ti/k3-socinfo.c b/drivers/soc/ti/k3-socinfo.c
index 19f3e74f5376..98348f998e0f 100644
--- a/drivers/soc/ti/k3-socinfo.c
+++ b/drivers/soc/ti/k3-socinfo.c
@@ -13,6 +13,7 @@
 #include <linux/slab.h>
 #include <linux/string.h>
 #include <linux/sys_soc.h>
+#include <linux/module.h>
 
 #define CTRLMMR_WKUP_JTAGID_REG		0
 /*
@@ -141,6 +142,7 @@ static const struct of_device_id k3_chipinfo_of_match[] = {
 	{ .compatible = "ti,am654-chipid", },
 	{ /* sentinel */ },
 };
+MODULE_DEVICE_TABLE(of, k3_chipinfo_of_match);
 
 static struct platform_driver k3_chipinfo_driver = {
 	.driver = {
@@ -156,3 +158,12 @@ static int __init k3_chipinfo_init(void)
 	return platform_driver_register(&k3_chipinfo_driver);
 }
 subsys_initcall(k3_chipinfo_init);
+
+static void __exit k3_chipinfo_exit(void)
+{
+	platform_driver_unregister(&k3_chipinfo_driver);
+}
+module_exit(k3_chipinfo_exit);
+
+MODULE_DESCRIPTION("TI K3 SoC info driver");
+MODULE_LICENSE("GPL");
-- 
2.25.1

Re: [PATCH v4 2/4] soc: ti: Add module build support

[Randy Dunlap]

Hi--

On 11/8/22 10:11, Nicolas Frayer wrote:
> Added module build support for the TI K3 SoC info driver.
> 
> Signed-off-by: Nicolas Frayer <nfrayer@baylibre.com>
> ---
>  arch/arm64/Kconfig.platforms |  1 -
>  drivers/soc/ti/Kconfig       |  3 ++-
>  drivers/soc/ti/k3-socinfo.c  | 11 +++++++++++
>  3 files changed, 13 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm64/Kconfig.platforms b/arch/arm64/Kconfig.platforms
> index 76580b932e44..4f2f92eb499f 100644
> --- a/arch/arm64/Kconfig.platforms
> +++ b/arch/arm64/Kconfig.platforms
> @@ -130,7 +130,6 @@ config ARCH_K3
>  	select TI_SCI_PROTOCOL
>  	select TI_SCI_INTR_IRQCHIP
>  	select TI_SCI_INTA_IRQCHIP
> -	select TI_K3_SOCINFO
>  	help
>  	  This enables support for Texas Instruments' K3 multicore SoC
>  	  architecture.
> diff --git a/drivers/soc/ti/Kconfig b/drivers/soc/ti/Kconfig
> index 7e2fb1c16af1..1a730c057cce 100644
> --- a/drivers/soc/ti/Kconfig
> +++ b/drivers/soc/ti/Kconfig
> @@ -74,7 +74,8 @@ config TI_K3_RINGACC
>  	  If unsure, say N.
>  
>  config TI_K3_SOCINFO
> -	bool
> +	tristate "TI K3 SoC info driver"
> +	default y

Maybe
	default ARCH_K3
?

>  	depends on ARCH_K3 || COMPILE_TEST
>  	select SOC_BUS
>  	select MFD_SYSCON


-- 
~Randy

Re: [PATCH v4 2/4] soc: ti: Add module build support

[Nicolas Frayer]

Hi Randy,

Le mar. 8 nov. 2022 à 19:18, Randy Dunlap <rdunlap@infradead.org> a écrit :
>
> Hi--
>
> On 11/8/22 10:11, Nicolas Frayer wrote:
> > Added module build support for the TI K3 SoC info driver.
> >
> > Signed-off-by: Nicolas Frayer <nfrayer@baylibre.com>
> > ---
> >  arch/arm64/Kconfig.platforms |  1 -
> >  drivers/soc/ti/Kconfig       |  3 ++-
> >  drivers/soc/ti/k3-socinfo.c  | 11 +++++++++++
> >  3 files changed, 13 insertions(+), 2 deletions(-)
> >
> > diff --git a/arch/arm64/Kconfig.platforms b/arch/arm64/Kconfig.platforms
> > index 76580b932e44..4f2f92eb499f 100644
> > --- a/arch/arm64/Kconfig.platforms
> > +++ b/arch/arm64/Kconfig.platforms
> > @@ -130,7 +130,6 @@ config ARCH_K3
> >       select TI_SCI_PROTOCOL
> >       select TI_SCI_INTR_IRQCHIP
> >       select TI_SCI_INTA_IRQCHIP
> > -     select TI_K3_SOCINFO
> >       help
> >         This enables support for Texas Instruments' K3 multicore SoC
> >         architecture.
> > diff --git a/drivers/soc/ti/Kconfig b/drivers/soc/ti/Kconfig
> > index 7e2fb1c16af1..1a730c057cce 100644
> > --- a/drivers/soc/ti/Kconfig
> > +++ b/drivers/soc/ti/Kconfig
> > @@ -74,7 +74,8 @@ config TI_K3_RINGACC
> >         If unsure, say N.
> >
> >  config TI_K3_SOCINFO
> > -     bool
> > +     tristate "TI K3 SoC info driver"
> > +     default y
>
> Maybe
>         default ARCH_K3
> ?

You're correct this should be defaulted to ARCH_K3.
This series will be dropped as it introduces dependency issues with
consumer drivers.

>
> >       depends on ARCH_K3 || COMPILE_TEST
> >       select SOC_BUS
> >       select MFD_SYSCON
>
>
> --
> ~Randy
Thanks,
Nicolas

Re: [PATCH v4 2/4] soc: ti: Add module build support

[Péter Ujfalusi]

On 08/11/2022 20:11, Nicolas Frayer wrote:
> Added module build support for the TI K3 SoC info driver.

Subject: "soc: ti: k3-socinfo: ..."

> 
> Signed-off-by: Nicolas Frayer <nfrayer@baylibre.com>
> ---
>   arch/arm64/Kconfig.platforms |  1 -
>   drivers/soc/ti/Kconfig       |  3 ++-
>   drivers/soc/ti/k3-socinfo.c  | 11 +++++++++++
>   3 files changed, 13 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm64/Kconfig.platforms b/arch/arm64/Kconfig.platforms
> index 76580b932e44..4f2f92eb499f 100644
> --- a/arch/arm64/Kconfig.platforms
> +++ b/arch/arm64/Kconfig.platforms
> @@ -130,7 +130,6 @@ config ARCH_K3
>   	select TI_SCI_PROTOCOL
>   	select TI_SCI_INTR_IRQCHIP
>   	select TI_SCI_INTA_IRQCHIP
> -	select TI_K3_SOCINFO
>   	help
>   	  This enables support for Texas Instruments' K3 multicore SoC
>   	  architecture.
> diff --git a/drivers/soc/ti/Kconfig b/drivers/soc/ti/Kconfig
> index 7e2fb1c16af1..1a730c057cce 100644
> --- a/drivers/soc/ti/Kconfig
> +++ b/drivers/soc/ti/Kconfig
> @@ -74,7 +74,8 @@ config TI_K3_RINGACC
>   	  If unsure, say N.
>   
>   config TI_K3_SOCINFO
> -	bool
> +	tristate "TI K3 SoC info driver"
> +	default y

Why it is a good thing to have this driver as module compared to always 
built in?
It has no dependencies, just things depending on it.
It is small, just couple of lines long

I don't really see the benefit of building it as a module, not even an 
academic one...


>   	depends on ARCH_K3 || COMPILE_TEST
>   	select SOC_BUS
>   	select MFD_SYSCON
> diff --git a/drivers/soc/ti/k3-socinfo.c b/drivers/soc/ti/k3-socinfo.c
> index 19f3e74f5376..98348f998e0f 100644
> --- a/drivers/soc/ti/k3-socinfo.c
> +++ b/drivers/soc/ti/k3-socinfo.c
> @@ -13,6 +13,7 @@
>   #include <linux/slab.h>
>   #include <linux/string.h>
>   #include <linux/sys_soc.h>
> +#include <linux/module.h>
>   
>   #define CTRLMMR_WKUP_JTAGID_REG		0
>   /*
> @@ -141,6 +142,7 @@ static const struct of_device_id k3_chipinfo_of_match[] = {
>   	{ .compatible = "ti,am654-chipid", },
>   	{ /* sentinel */ },
>   };
> +MODULE_DEVICE_TABLE(of, k3_chipinfo_of_match);
>   
>   static struct platform_driver k3_chipinfo_driver = {
>   	.driver = {
> @@ -156,3 +158,12 @@ static int __init k3_chipinfo_init(void)
>   	return platform_driver_register(&k3_chipinfo_driver);
>   }
>   subsys_initcall(k3_chipinfo_init);

subsys_initcall for a module?

> +
> +static void __exit k3_chipinfo_exit(void)
> +{
> +	platform_driver_unregister(&k3_chipinfo_driver);
> +}
> +module_exit(k3_chipinfo_exit);
> +
> +MODULE_DESCRIPTION("TI K3 SoC info driver");
> +MODULE_LICENSE("GPL");

-- 
Péter

Re: [PATCH v4 2/4] soc: ti: Add module build support

[Nicolas Frayer]

Le jeu. 24 nov. 2022 à 08:53, Péter Ujfalusi
<peter.ujfalusi@gmail.com> a écrit :

Hi Peter,
>
>
>
> On 08/11/2022 20:11, Nicolas Frayer wrote:
> > Added module build support for the TI K3 SoC info driver.
>
> Subject: "soc: ti: k3-socinfo: ..."
>
> >
> > Signed-off-by: Nicolas Frayer <nfrayer@baylibre.com>
> > ---
> >   arch/arm64/Kconfig.platforms |  1 -
> >   drivers/soc/ti/Kconfig       |  3 ++-
> >   drivers/soc/ti/k3-socinfo.c  | 11 +++++++++++
> >   3 files changed, 13 insertions(+), 2 deletions(-)
> >
> > diff --git a/arch/arm64/Kconfig.platforms b/arch/arm64/Kconfig.platforms
> > index 76580b932e44..4f2f92eb499f 100644
> > --- a/arch/arm64/Kconfig.platforms
> > +++ b/arch/arm64/Kconfig.platforms
> > @@ -130,7 +130,6 @@ config ARCH_K3
> >       select TI_SCI_PROTOCOL
> >       select TI_SCI_INTR_IRQCHIP
> >       select TI_SCI_INTA_IRQCHIP
> > -     select TI_K3_SOCINFO
> >       help
> >         This enables support for Texas Instruments' K3 multicore SoC
> >         architecture.
> > diff --git a/drivers/soc/ti/Kconfig b/drivers/soc/ti/Kconfig
> > index 7e2fb1c16af1..1a730c057cce 100644
> > --- a/drivers/soc/ti/Kconfig
> > +++ b/drivers/soc/ti/Kconfig
> > @@ -74,7 +74,8 @@ config TI_K3_RINGACC
> >         If unsure, say N.
> >
> >   config TI_K3_SOCINFO
> > -     bool
> > +     tristate "TI K3 SoC info driver"
> > +     default y
>
> Why it is a good thing to have this driver as module compared to always
> built in?
> It has no dependencies, just things depending on it.
> It is small, just couple of lines long
>
> I don't really see the benefit of building it as a module, not even an
> academic one...
>

Just to give an update, this series will be dropped as it introduces
dependency issues
with consumer drivers.
The reason why I've enabled the module build support is because it is
required to build
vendor drivers as modules for Android GKI feature.

>
> >       depends on ARCH_K3 || COMPILE_TEST
> >       select SOC_BUS
> >       select MFD_SYSCON
> > diff --git a/drivers/soc/ti/k3-socinfo.c b/drivers/soc/ti/k3-socinfo.c
> > index 19f3e74f5376..98348f998e0f 100644
> > --- a/drivers/soc/ti/k3-socinfo.c
> > +++ b/drivers/soc/ti/k3-socinfo.c
> > @@ -13,6 +13,7 @@
> >   #include <linux/slab.h>
> >   #include <linux/string.h>
> >   #include <linux/sys_soc.h>
> > +#include <linux/module.h>
> >
> >   #define CTRLMMR_WKUP_JTAGID_REG             0
> >   /*
> > @@ -141,6 +142,7 @@ static const struct of_device_id k3_chipinfo_of_match[] = {
> >       { .compatible = "ti,am654-chipid", },
> >       { /* sentinel */ },
> >   };
> > +MODULE_DEVICE_TABLE(of, k3_chipinfo_of_match);
> >
> >   static struct platform_driver k3_chipinfo_driver = {
> >       .driver = {
> > @@ -156,3 +158,12 @@ static int __init k3_chipinfo_init(void)
> >       return platform_driver_register(&k3_chipinfo_driver);
> >   }
> >   subsys_initcall(k3_chipinfo_init);
>
> subsys_initcall for a module?

By including module.h, the subsys_initcall() is redefined as
module_init() when built
as a module. When built-in, it is redefined as the usual __initcall.

>
> > +
> > +static void __exit k3_chipinfo_exit(void)
> > +{
> > +     platform_driver_unregister(&k3_chipinfo_driver);
> > +}
> > +module_exit(k3_chipinfo_exit);
> > +
> > +MODULE_DESCRIPTION("TI K3 SoC info driver");
> > +MODULE_LICENSE("GPL");
>
> --
> Péter

[PATCH v4 3/4] dmaengine: ti: k3-udma: Deferring probe when soc_device_match() returns NULL

[Nicolas Frayer]

When the k3 socinfo driver is built as a module, there is a possibility
that it will probe after the k3 udma driver and the later returns -ENODEV.
By deferring the k3 udma probe we allow the k3 socinfo to probe and
register the soc_device_attribute structure needed by the k3 udma driver.

Signed-off-by: Nicolas Frayer <nfrayer@baylibre.com>
---
 drivers/dma/ti/k3-udma.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma/ti/k3-udma.c b/drivers/dma/ti/k3-udma.c
index 7b5081989b3d..a6bb5077900b 100644
--- a/drivers/dma/ti/k3-udma.c
+++ b/drivers/dma/ti/k3-udma.c
@@ -5285,7 +5285,7 @@ static int udma_probe(struct platform_device *pdev)
 	soc = soc_device_match(k3_soc_devices);
 	if (!soc) {
 		dev_err(dev, "No compatible SoC found\n");
-		return -ENODEV;
+		return -EPROBE_DEFER;
 	}
 	ud->soc_data = soc->data;
 
-- 
2.25.1

[PATCH v4 4/4] net: ethernet: ti: davinci_mdio: Deferring probe when soc_device_match() returns NULL

[Nicolas Frayer]

When the k3 socinfo driver is built as a module, there is a possibility
that it will probe after the davinci mdio driver. By deferring the mdio
probe we allow the k3 socinfo to probe and register the
soc_device_attribute structure needed by the mdio driver.

Signed-off-by: Nicolas Frayer <nfrayer@baylibre.com>
---
 drivers/net/ethernet/ti/davinci_mdio.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/ethernet/ti/davinci_mdio.c b/drivers/net/ethernet/ti/davinci_mdio.c
index 946b9753ccfb..095198b6b7be 100644
--- a/drivers/net/ethernet/ti/davinci_mdio.c
+++ b/drivers/net/ethernet/ti/davinci_mdio.c
@@ -533,6 +533,10 @@ static int davinci_mdio_probe(struct platform_device *pdev)
 		const struct soc_device_attribute *soc_match_data;
 
 		soc_match_data = soc_device_match(k3_mdio_socinfo);
+
+		if (!soc_match_data)
+			return -EPROBE_DEFER;
+
 		if (soc_match_data && soc_match_data->data) {
 			const struct k3_mdio_soc_data *socdata =
 						soc_match_data->data;
-- 
2.25.1

Re: [PATCH v4 4/4] net: ethernet: ti: davinci_mdio: Deferring probe when soc_device_match() returns NULL

[Paolo Abeni]

Hello,

On Tue, 2022-11-08 at 19:11 +0100, Nicolas Frayer wrote:
> When the k3 socinfo driver is built as a module, there is a possibility
> that it will probe after the davinci mdio driver. By deferring the mdio
> probe we allow the k3 socinfo to probe and register the
> soc_device_attribute structure needed by the mdio driver.
> 
> Signed-off-by: Nicolas Frayer <nfrayer@baylibre.com>

I guess this one will go via the arm tree, right?

I'm dropping it from the netdev PW.

Thanks,

Paolo

Re: [PATCH v4 4/4] net: ethernet: ti: davinci_mdio: Deferring probe when soc_device_match() returns NULL

[Nicolas Frayer]

Le jeu. 10 nov. 2022 à 12:21, Paolo Abeni <pabeni@redhat.com> a écrit :
>
> Hello,
>
> On Tue, 2022-11-08 at 19:11 +0100, Nicolas Frayer wrote:
> > When the k3 socinfo driver is built as a module, there is a possibility
> > that it will probe after the davinci mdio driver. By deferring the mdio
> > probe we allow the k3 socinfo to probe and register the
> > soc_device_attribute structure needed by the mdio driver.
> >
> > Signed-off-by: Nicolas Frayer <nfrayer@baylibre.com>
>
> I guess this one will go via the arm tree, right?
>
> I'm dropping it from the netdev PW.
>
> Thanks,
>
> Paolo
>
Hello Paolo,

I will resend this series as individual patches, so can you please
apply this mdio patch individually as it's independent from the others ?

Thanks,

Nicolas

Re: [PATCH v4 4/4] net: ethernet: ti: davinci_mdio: Deferring probe when soc_device_match() returns NULL

[Vignesh Raghavendra]

Hi Nicolas,

On 08/11/22 11:41 pm, Nicolas Frayer wrote:
> When the k3 socinfo driver is built as a module, there is a possibility
> that it will probe after the davinci mdio driver. By deferring the mdio
> probe we allow the k3 socinfo to probe and register the
> soc_device_attribute structure needed by the mdio driver.
> 
> Signed-off-by: Nicolas Frayer <nfrayer@baylibre.com>
> ---
>  drivers/net/ethernet/ti/davinci_mdio.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/net/ethernet/ti/davinci_mdio.c b/drivers/net/ethernet/ti/davinci_mdio.c
> index 946b9753ccfb..095198b6b7be 100644
> --- a/drivers/net/ethernet/ti/davinci_mdio.c
> +++ b/drivers/net/ethernet/ti/davinci_mdio.c
> @@ -533,6 +533,10 @@ static int davinci_mdio_probe(struct platform_device *pdev)
>  		const struct soc_device_attribute *soc_match_data;
>  
>  		soc_match_data = soc_device_match(k3_mdio_socinfo);
> +
> +		if (!soc_match_data)
> +			return -EPROBE_DEFER;

I dont think this is right way to detect if socinfo driver is probed.
Per documentation of soc_device_match() , function will return NULL if
it does not match any of the entries in k3_mdio_socinfo (ie if we are
running on any platforms other that ones in the list)

Note that this driver is used on TI's 32 bit SoCs too that dont even
have a k3-socinfo driver equivalent. In such case, this code will end up
probe deferring indefinitely.

> +
>  		if (soc_match_data && soc_match_data->data) {
>  			const struct k3_mdio_soc_data *socdata =
>  						soc_match_data->data;

Re: [PATCH v4 4/4] net: ethernet: ti: davinci_mdio: Deferring probe when soc_device_match() returns NULL

[Kevin Hilman]

Hi Vignesh,

Vignesh Raghavendra <vigneshr@ti.com> writes:

> Hi Nicolas,
>
> On 08/11/22 11:41 pm, Nicolas Frayer wrote:
>> When the k3 socinfo driver is built as a module, there is a possibility
>> that it will probe after the davinci mdio driver. By deferring the mdio
>> probe we allow the k3 socinfo to probe and register the
>> soc_device_attribute structure needed by the mdio driver.
>> 
>> Signed-off-by: Nicolas Frayer <nfrayer@baylibre.com>
>> ---
>>  drivers/net/ethernet/ti/davinci_mdio.c | 4 ++++
>>  1 file changed, 4 insertions(+)
>> 
>> diff --git a/drivers/net/ethernet/ti/davinci_mdio.c b/drivers/net/ethernet/ti/davinci_mdio.c
>> index 946b9753ccfb..095198b6b7be 100644
>> --- a/drivers/net/ethernet/ti/davinci_mdio.c
>> +++ b/drivers/net/ethernet/ti/davinci_mdio.c
>> @@ -533,6 +533,10 @@ static int davinci_mdio_probe(struct platform_device *pdev)
>>  		const struct soc_device_attribute *soc_match_data;
>>  
>>  		soc_match_data = soc_device_match(k3_mdio_socinfo);
>> +
>> +		if (!soc_match_data)
>> +			return -EPROBE_DEFER;
>
> I dont think this is right way to detect if socinfo driver is probed.
> Per documentation of soc_device_match() , function will return NULL if
> it does not match any of the entries in k3_mdio_socinfo (ie if we are
> running on any platforms other that ones in the list)
>
> Note that this driver is used on TI's 32 bit SoCs too that dont even
> have a k3-socinfo driver equivalent. In such case, this code will end up
> probe deferring indefinitely.

Yes, you're right.  This is not the right solution and this patch should
be dropped. We'll need to have a deeper look at socinfo to figure out
if/how it could be configured to support a fully modular kernel.

Kevin