[PATCH 1/3] net: stmmac: explicitly deassert GMAC_AHB_RESET

[PATCH 1/3] net: stmmac: explicitly deassert GMAC_AHB_RESET

[Matthew Hagan]

We are currently assuming that GMAC_AHB_RESET will already be deasserted
by the bootloader. However if this has not been done, probing of the GMAC
will fail. To remedy this we must ensure GMAC_AHB_RESET has been deasserted
prior to probing.

Signed-off-by: Matthew Hagan <mnhagan88@gmail.com>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c     | 7 +++++++
 drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c | 7 +++++++
 include/linux/stmmac.h                                | 1 +
 3 files changed, 15 insertions(+)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 6d41dd6f9f7a..1e28058b65a8 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -6840,6 +6840,13 @@ int stmmac_dvr_probe(struct device *device,
 			reset_control_reset(priv->plat->stmmac_rst);
 	}
 
+	if (priv->plat->stmmac_ahb_rst) {
+		ret = reset_control_deassert(priv->plat->stmmac_ahb_rst);
+		if (ret == -ENOTSUPP)
+			dev_err(priv->device,
+				"unable to bring out of ahb reset\n");
+	}
+
 	/* Init MAC and get the capabilities */
 	ret = stmmac_hw_init(priv);
 	if (ret)
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
index 97a1fedcc9ac..d8ae58bdbbe3 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
@@ -600,6 +600,13 @@ stmmac_probe_config_dt(struct platform_device *pdev, u8 *mac)
 		goto error_hw_init;
 	}
 
+	plat->stmmac_ahb_rst = devm_reset_control_get_optional_shared(
+							&pdev->dev, "ahb");
+	if (IS_ERR(plat->stmmac_ahb_rst)) {
+		ret = plat->stmmac_ahb_rst;
+		goto error_hw_init;
+	}
+
 	return plat;
 
 error_hw_init:
diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
index e55a4807e3ea..9b6a64f3e3dc 100644
--- a/include/linux/stmmac.h
+++ b/include/linux/stmmac.h
@@ -239,6 +239,7 @@ struct plat_stmmacenet_data {
 	unsigned int mult_fact_100ns;
 	s32 ptp_max_adj;
 	struct reset_control *stmmac_rst;
+	struct reset_control *stmmac_ahb_rst;
 	struct stmmac_axi *axi;
 	int has_gmac4;
 	bool has_sun8i;
-- 
2.26.3

[PATCH 2/3] ARM: dts: qcom: add ahb reset to ipq806x-gmac

[Matthew Hagan]

Add GMAC_AHB_RESET to the resets property of each gmac node.

Signed-off-by: Matthew Hagan <mnhagan88@gmail.com>
---
 arch/arm/boot/dts/qcom-ipq8064.dtsi | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/arch/arm/boot/dts/qcom-ipq8064.dtsi b/arch/arm/boot/dts/qcom-ipq8064.dtsi
index 98995ead4413..1dbceaf3454b 100644
--- a/arch/arm/boot/dts/qcom-ipq8064.dtsi
+++ b/arch/arm/boot/dts/qcom-ipq8064.dtsi
@@ -643,8 +643,9 @@ gmac0: ethernet@37000000 {
 			clocks = <&gcc GMAC_CORE1_CLK>;
 			clock-names = "stmmaceth";
 
-			resets = <&gcc GMAC_CORE1_RESET>;
-			reset-names = "stmmaceth";
+			resets = <&gcc GMAC_CORE1_RESET>,
+				 <&gcc GMAC_AHB_RESET>;
+			reset-names = "stmmaceth", "ahb";
 
 			status = "disabled";
 		};
@@ -666,8 +667,9 @@ gmac1: ethernet@37200000 {
 			clocks = <&gcc GMAC_CORE2_CLK>;
 			clock-names = "stmmaceth";
 
-			resets = <&gcc GMAC_CORE2_RESET>;
-			reset-names = "stmmaceth";
+			resets = <&gcc GMAC_CORE2_RESET>,
+				 <&gcc GMAC_AHB_RESET>;
+			reset-names = "stmmaceth", "ahb";
 
 			status = "disabled";
 		};
@@ -689,8 +691,9 @@ gmac2: ethernet@37400000 {
 			clocks = <&gcc GMAC_CORE3_CLK>;
 			clock-names = "stmmaceth";
 
-			resets = <&gcc GMAC_CORE3_RESET>;
-			reset-names = "stmmaceth";
+			resets = <&gcc GMAC_CORE3_RESET>,
+				 <&gcc GMAC_AHB_RESET>;
+			reset-names = "stmmaceth", "ahb";
 
 			status = "disabled";
 		};
@@ -712,8 +715,9 @@ gmac3: ethernet@37600000 {
 			clocks = <&gcc GMAC_CORE4_CLK>;
 			clock-names = "stmmaceth";
 
-			resets = <&gcc GMAC_CORE4_RESET>;
-			reset-names = "stmmaceth";
+			resets = <&gcc GMAC_CORE4_RESET>,
+				 <&gcc GMAC_AHB_RESET>;
+			reset-names = "stmmaceth", "ahb";
 
 			status = "disabled";
 		};
-- 
2.26.3

[PATCH 3/3] dt-bindings: net: stmmac: add ahb reset to example

[Matthew Hagan]

Add ahb reset to the reset properties within the example gmac node.

Signed-off-by: Matthew Hagan <mnhagan88@gmail.com>
---
 Documentation/devicetree/bindings/net/ipq806x-dwmac.txt | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/net/ipq806x-dwmac.txt b/Documentation/devicetree/bindings/net/ipq806x-dwmac.txt
index 6d7ab4e524d4..ef5fd9f0b156 100644
--- a/Documentation/devicetree/bindings/net/ipq806x-dwmac.txt
+++ b/Documentation/devicetree/bindings/net/ipq806x-dwmac.txt
@@ -30,6 +30,7 @@ Example:
 		clocks = <&gcc GMAC_CORE1_CLK>;
 		clock-names = "stmmaceth";
 
-		resets = <&gcc GMAC_CORE1_RESET>;
-		reset-names = "stmmaceth";
+		resets = <&gcc GMAC_CORE1_RESET>,
+			 <&gcc GMAC_AHB_RESET>;
+		reset-names = "stmmaceth", "ahb";
 	};
-- 
2.26.3

Re: [PATCH 1/3] net: stmmac: explicitly deassert GMAC_AHB_RESET

[Bjorn Andersson]

On Sat 05 Jun 12:35 CDT 2021, Matthew Hagan wrote:

> We are currently assuming that GMAC_AHB_RESET will already be deasserted
> by the bootloader. However if this has not been done, probing of the GMAC
> will fail. To remedy this we must ensure GMAC_AHB_RESET has been deasserted
> prior to probing.
> 

Sounds good, just some small style comments below.

> Signed-off-by: Matthew Hagan <mnhagan88@gmail.com>
> ---
>  drivers/net/ethernet/stmicro/stmmac/stmmac_main.c     | 7 +++++++
>  drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c | 7 +++++++
>  include/linux/stmmac.h                                | 1 +
>  3 files changed, 15 insertions(+)
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> index 6d41dd6f9f7a..1e28058b65a8 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> @@ -6840,6 +6840,13 @@ int stmmac_dvr_probe(struct device *device,
>  			reset_control_reset(priv->plat->stmmac_rst);
>  	}
>  
> +	if (priv->plat->stmmac_ahb_rst) {

You don't need this conditional, stmmac_ahb_rst will be NULL if not
specified and you can reset_control_deassert(NULL) without any problems.

> +		ret = reset_control_deassert(priv->plat->stmmac_ahb_rst);
> +		if (ret == -ENOTSUPP)
> +			dev_err(priv->device,
> +				"unable to bring out of ahb reset\n");

No need to wrap this line.

> +	}
> +
>  	/* Init MAC and get the capabilities */
>  	ret = stmmac_hw_init(priv);
>  	if (ret)
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> index 97a1fedcc9ac..d8ae58bdbbe3 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> @@ -600,6 +600,13 @@ stmmac_probe_config_dt(struct platform_device *pdev, u8 *mac)
>  		goto error_hw_init;
>  	}
>  
> +	plat->stmmac_ahb_rst = devm_reset_control_get_optional_shared(
> +							&pdev->dev, "ahb");
> +	if (IS_ERR(plat->stmmac_ahb_rst)) {
> +		ret = plat->stmmac_ahb_rst;

You need a PTR_ERR() around the plat->stmmac_ahb_rst.

Regards,
Bjorn

> +		goto error_hw_init;
> +	}
> +
>  	return plat;
>  
>  error_hw_init:
> diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
> index e55a4807e3ea..9b6a64f3e3dc 100644
> --- a/include/linux/stmmac.h
> +++ b/include/linux/stmmac.h
> @@ -239,6 +239,7 @@ struct plat_stmmacenet_data {
>  	unsigned int mult_fact_100ns;
>  	s32 ptp_max_adj;
>  	struct reset_control *stmmac_rst;
> +	struct reset_control *stmmac_ahb_rst;
>  	struct stmmac_axi *axi;
>  	int has_gmac4;
>  	bool has_sun8i;
> -- 
> 2.26.3
> 

Re: [PATCH 1/3] net: stmmac: explicitly deassert GMAC_AHB_RESET

[Matthew Hagan]

On 06/06/2021 04:24, Bjorn Andersson wrote:

> On Sat 05 Jun 12:35 CDT 2021, Matthew Hagan wrote:
>
>> We are currently assuming that GMAC_AHB_RESET will already be deasserted
>> by the bootloader. However if this has not been done, probing of the GMAC
>> will fail. To remedy this we must ensure GMAC_AHB_RESET has been deasserted
>> prior to probing.
>>
> Sounds good, just some small style comments below.
>
>> Signed-off-by: Matthew Hagan <mnhagan88@gmail.com>
>> ---
>>  drivers/net/ethernet/stmicro/stmmac/stmmac_main.c     | 7 +++++++
>>  drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c | 7 +++++++
>>  include/linux/stmmac.h                                | 1 +
>>  3 files changed, 15 insertions(+)
>>
>> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
>> index 6d41dd6f9f7a..1e28058b65a8 100644
>> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
>> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
>> @@ -6840,6 +6840,13 @@ int stmmac_dvr_probe(struct device *device,
>>  			reset_control_reset(priv->plat->stmmac_rst);
>>  	}
>>  
>> +	if (priv->plat->stmmac_ahb_rst) {
> You don't need this conditional, stmmac_ahb_rst will be NULL if not
> specified and you can reset_control_deassert(NULL) without any problems.
>
>> +		ret = reset_control_deassert(priv->plat->stmmac_ahb_rst);
>> +		if (ret == -ENOTSUPP)
>> +			dev_err(priv->device,
>> +				"unable to bring out of ahb reset\n");
> No need to wrap this line.
>
>> +	}
>> +
>>  	/* Init MAC and get the capabilities */
>>  	ret = stmmac_hw_init(priv);
>>  	if (ret)
>> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
>> index 97a1fedcc9ac..d8ae58bdbbe3 100644
>> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
>> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
>> @@ -600,6 +600,13 @@ stmmac_probe_config_dt(struct platform_device *pdev, u8 *mac)
>>  		goto error_hw_init;
>>  	}
>>  
>> +	plat->stmmac_ahb_rst = devm_reset_control_get_optional_shared(
>> +							&pdev->dev, "ahb");
>> +	if (IS_ERR(plat->stmmac_ahb_rst)) {
>> +		ret = plat->stmmac_ahb_rst;
> You need a PTR_ERR() around the plat->stmmac_ahb_rst.
>
> Regards,
> Bjorn
>
>> +		goto error_hw_init;
>> +	}
>> +
>>  	return plat;
>>  
>>  error_hw_init:
>> diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
>> index e55a4807e3ea..9b6a64f3e3dc 100644
>> --- a/include/linux/stmmac.h
>> +++ b/include/linux/stmmac.h
>> @@ -239,6 +239,7 @@ struct plat_stmmacenet_data {
>>  	unsigned int mult_fact_100ns;
>>  	s32 ptp_max_adj;
>>  	struct reset_control *stmmac_rst;
>> +	struct reset_control *stmmac_ahb_rst;
>>  	struct stmmac_axi *axi;
>>  	int has_gmac4;
>>  	bool has_sun8i;
>> -- 
>> 2.26.3
>>
>>
Thanks for the review. Will submit a v2 shortly.

Matthew

[PATCH v2] net: stmmac: explicitly deassert GMAC_AHB_RESET

[Matthew Hagan]

We are currently assuming that GMAC_AHB_RESET will already be deasserted
by the bootloader. However if this has not been done, probing of the GMAC
will fail. To remedy this we must ensure GMAC_AHB_RESET has been deasserted
prior to probing.

v2 changes:
 - remove NULL condition check for stmmac_ahb_rst in stmmac_main.c
 - unwrap dev_err() message in stmmac_main.c
 - add PTR_ERR() around plat->stmmac_ahb_rst in stmmac_platform.c

Signed-off-by: Matthew Hagan <mnhagan88@gmail.com>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c     | 4 ++++
 drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c | 7 +++++++
 include/linux/stmmac.h                                | 1 +
 3 files changed, 12 insertions(+)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 6d41dd6f9f7a..0d4cb423cbbd 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -6840,6 +6840,10 @@ int stmmac_dvr_probe(struct device *device,
 			reset_control_reset(priv->plat->stmmac_rst);
 	}
 
+	ret = reset_control_deassert(priv->plat->stmmac_ahb_rst);
+	if (ret == -ENOTSUPP)
+		dev_err(priv->device, "unable to bring out of ahb reset\n");
+
 	/* Init MAC and get the capabilities */
 	ret = stmmac_hw_init(priv);
 	if (ret)
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
index 97a1fedcc9ac..a178181f6a24 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
@@ -600,6 +600,13 @@ stmmac_probe_config_dt(struct platform_device *pdev, u8 *mac)
 		goto error_hw_init;
 	}
 
+	plat->stmmac_ahb_rst = devm_reset_control_get_optional_shared(
+							&pdev->dev, "ahb");
+	if (IS_ERR(plat->stmmac_ahb_rst)) {
+		ret = PTR_ERR(plat->stmmac_ahb_rst);
+		goto error_hw_init;
+	}
+
 	return plat;
 
 error_hw_init:
diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
index e55a4807e3ea..9b6a64f3e3dc 100644
--- a/include/linux/stmmac.h
+++ b/include/linux/stmmac.h
@@ -239,6 +239,7 @@ struct plat_stmmacenet_data {
 	unsigned int mult_fact_100ns;
 	s32 ptp_max_adj;
 	struct reset_control *stmmac_rst;
+	struct reset_control *stmmac_ahb_rst;
 	struct stmmac_axi *axi;
 	int has_gmac4;
 	bool has_sun8i;
-- 
2.26.3

Re: [PATCH 1/3] net: stmmac: explicitly deassert GMAC_AHB_RESET

[Matthew Hagan]

On 06/06/2021 04:24, Bjorn Andersson wrote:

>> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
>> index 97a1fedcc9ac..d8ae58bdbbe3 100644
>> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
>> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
>> @@ -600,6 +600,13 @@ stmmac_probe_config_dt(struct platform_device *pdev, u8 *mac)
>>  		goto error_hw_init;
>>  	}
>>  
>> +	plat->stmmac_ahb_rst = devm_reset_control_get_optional_shared(
>> +							&pdev->dev, "ahb");
>> +	if (IS_ERR(plat->stmmac_ahb_rst)) {
>> +		ret = plat->stmmac_ahb_rst;
> You need a PTR_ERR() around the plat->stmmac_ahb_rst.

This is giving a warning. Shouldn't v1 be kept as it is here? Please refer
to "net: stmmac: platform: use optional clk/reset get APIs" [1] which
modified error handling for plat->stmmac_rst. PTR_ERR() would then be
called by the parent function on the returned value of ret.

[1]: https://lore.kernel.org/netdev/20201112092606.5173aa6f@xhacker.debian/

Thanks,
Matthew

Re: [PATCH v2] net: stmmac: explicitly deassert GMAC_AHB_RESET

[Philipp Zabel]

On Sun, 2021-06-06 at 11:30 +0100, Matthew Hagan wrote:
> We are currently assuming that GMAC_AHB_RESET will already be deasserted
> by the bootloader. However if this has not been done, probing of the GMAC
> will fail. To remedy this we must ensure GMAC_AHB_RESET has been deasserted
> prior to probing.
> 
> v2 changes:
>  - remove NULL condition check for stmmac_ahb_rst in stmmac_main.c
>  - unwrap dev_err() message in stmmac_main.c
>  - add PTR_ERR() around plat->stmmac_ahb_rst in stmmac_platform.c
> 
> Signed-off-by: Matthew Hagan <mnhagan88@gmail.com>
> ---
>  drivers/net/ethernet/stmicro/stmmac/stmmac_main.c     | 4 ++++
>  drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c | 7 +++++++
>  include/linux/stmmac.h                                | 1 +
>  3 files changed, 12 insertions(+)
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> index 6d41dd6f9f7a..0d4cb423cbbd 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> @@ -6840,6 +6840,10 @@ int stmmac_dvr_probe(struct device *device,
>  			reset_control_reset(priv->plat->stmmac_rst);
>  	}
>  
> +	ret = reset_control_deassert(priv->plat->stmmac_ahb_rst);
> +	if (ret == -ENOTSUPP)
> +		dev_err(priv->device, "unable to bring out of ahb reset\n");
> +

I would make this

	if (ret)
		dev_err(priv->device, "unable to bring out of ahb reset: %pe\n", ERR_PTR(ret));

Also consider asserting the reset again in the remove path. Or is there
a reason not to?

With that addressed,

Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>

regards
Philipp

Re: [PATCH v2] net: stmmac: explicitly deassert GMAC_AHB_RESET

[Matthew Hagan]

On 07/06/2021 10:45, Philipp Zabel wrote:

> On Sun, 2021-06-06 at 11:30 +0100, Matthew Hagan wrote:
>> We are currently assuming that GMAC_AHB_RESET will already be deasserted
>> by the bootloader. However if this has not been done, probing of the GMAC
>> will fail. To remedy this we must ensure GMAC_AHB_RESET has been deasserted
>> prior to probing.
>>
>> v2 changes:
>>  - remove NULL condition check for stmmac_ahb_rst in stmmac_main.c
>>  - unwrap dev_err() message in stmmac_main.c
>>  - add PTR_ERR() around plat->stmmac_ahb_rst in stmmac_platform.c
>>
>> Signed-off-by: Matthew Hagan <mnhagan88@gmail.com>
>> ---
>>  drivers/net/ethernet/stmicro/stmmac/stmmac_main.c     | 4 ++++
>>  drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c | 7 +++++++
>>  include/linux/stmmac.h                                | 1 +
>>  3 files changed, 12 insertions(+)
>>
>> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
>> index 6d41dd6f9f7a..0d4cb423cbbd 100644
>> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
>> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
>> @@ -6840,6 +6840,10 @@ int stmmac_dvr_probe(struct device *device,
>>  			reset_control_reset(priv->plat->stmmac_rst);
>>  	}
>>  
>> +	ret = reset_control_deassert(priv->plat->stmmac_ahb_rst);
>> +	if (ret == -ENOTSUPP)
>> +		dev_err(priv->device, "unable to bring out of ahb reset\n");
>> +
> I would make this
>
> 	if (ret)
> 		dev_err(priv->device, "unable to bring out of ahb reset: %pe\n", ERR_PTR(ret));

Done.

>
> Also consider asserting the reset again in the remove path. Or is there
> a reason not to?

Don't see any issue doing this. As this is a shared reset, the assert will only occur
when the final GMAC is removed, due to the tracking of deassert_count.

> With that addressed,
>
> Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
>
> regards
> Philipp

Thanks,

Matthew

[PATCH v3] net: stmmac: explicitly deassert GMAC_AHB_RESET

[Matthew Hagan]

We are currently assuming that GMAC_AHB_RESET will already be deasserted
by the bootloader. However if this has not been done, probing of the GMAC
will fail. To remedy this we must ensure GMAC_AHB_RESET has been deasserted
prior to probing.

v2 changes:
 - remove NULL condition check for stmmac_ahb_rst in stmmac_main.c
 - unwrap dev_err() message in stmmac_main.c
 - add PTR_ERR() around plat->stmmac_ahb_rst in stmmac_platform.c

v3 changes:
 - add error pointer to dev_err() output
 - add reset_control_assert(stmmac_ahb_rst) in stmmac_dvr_remove
 - revert PTR_ERR() around plat->stmmac_ahb_rst since this is performed
   on the returned value of ret by the calling function

Signed-off-by: Matthew Hagan <mnhagan88@gmail.com>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c     | 6 ++++++
 drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c | 7 +++++++
 include/linux/stmmac.h                                | 1 +
 3 files changed, 14 insertions(+)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 6d41dd6f9f7a..78dafde70671 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -6840,6 +6840,11 @@ int stmmac_dvr_probe(struct device *device,
 			reset_control_reset(priv->plat->stmmac_rst);
 	}
 
+	ret = reset_control_deassert(priv->plat->stmmac_ahb_rst);
+	if (ret == -ENOTSUPP)
+		dev_err(priv->device, "unable to bring out of ahb reset: %pe\n",
+			ERR_PTR(ret));
+
 	/* Init MAC and get the capabilities */
 	ret = stmmac_hw_init(priv);
 	if (ret)
@@ -7072,6 +7077,7 @@ int stmmac_dvr_remove(struct device *dev)
 	phylink_destroy(priv->phylink);
 	if (priv->plat->stmmac_rst)
 		reset_control_assert(priv->plat->stmmac_rst);
+	reset_control_assert(priv->plat->stmmac_ahb_rst);
 	pm_runtime_put(dev);
 	pm_runtime_disable(dev);
 	if (priv->hw->pcs != STMMAC_PCS_TBI &&
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
index 97a1fedcc9ac..d8ae58bdbbe3 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
@@ -600,6 +600,13 @@ stmmac_probe_config_dt(struct platform_device *pdev, u8 *mac)
 		goto error_hw_init;
 	}
 
+	plat->stmmac_ahb_rst = devm_reset_control_get_optional_shared(
+							&pdev->dev, "ahb");
+	if (IS_ERR(plat->stmmac_ahb_rst)) {
+		ret = plat->stmmac_ahb_rst;
+		goto error_hw_init;
+	}
+
 	return plat;
 
 error_hw_init:
diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
index e55a4807e3ea..9b6a64f3e3dc 100644
--- a/include/linux/stmmac.h
+++ b/include/linux/stmmac.h
@@ -239,6 +239,7 @@ struct plat_stmmacenet_data {
 	unsigned int mult_fact_100ns;
 	s32 ptp_max_adj;
 	struct reset_control *stmmac_rst;
+	struct reset_control *stmmac_ahb_rst;
 	struct stmmac_axi *axi;
 	int has_gmac4;
 	bool has_sun8i;
-- 
2.26.3

Re: [PATCH v3] net: stmmac: explicitly deassert GMAC_AHB_RESET

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net-next.git (refs/heads/master):

On Tue,  8 Jun 2021 19:59:06 +0100 you wrote:
> We are currently assuming that GMAC_AHB_RESET will already be deasserted
> by the bootloader. However if this has not been done, probing of the GMAC
> will fail. To remedy this we must ensure GMAC_AHB_RESET has been deasserted
> prior to probing.
> 
> v2 changes:
>  - remove NULL condition check for stmmac_ahb_rst in stmmac_main.c
>  - unwrap dev_err() message in stmmac_main.c
>  - add PTR_ERR() around plat->stmmac_ahb_rst in stmmac_platform.c
> 
> [...]

Here is the summary with links:
  - [v3] net: stmmac: explicitly deassert GMAC_AHB_RESET
    https://git.kernel.org/netdev/net-next/c/e67f325e9cd6

You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html