[v2] PCI: tegra194: Fix debugfs directory creation when CONFIG_PCIEASPM is disabled

[v2] PCI: tegra194: Fix debugfs directory creation when CONFIG_PCIEASPM is disabled

[Hans Zhang]

Previously, the debugfs directory was unconditionally created in
tegra_pcie_config_rp() regardless of the CONFIG_PCIEASPM setting.
This led to unnecessary directory creation when ASPM support was disabled.

Move the debugfs directory creation into init_debugfs() which is
conditionally compiled based on CONFIG_PCIEASPM. This ensures:
- The directory is only created when ASPM-related debugfs entries are
  needed.
- Proper error handling for directory creation failures.
- Avoids cluttering debugfs with empty directories when ASPM is disabled.

Signed-off-by: Hans Zhang <18255117159@163.com>
---
Changes since v1:
https://lore.kernel.org/linux-pci/20250405145459.26800-1-18255117159@163.com

- The first version was committed incorrectly because the judgment
  parameter in "debugfs_remove_recursive" was not noticed.
---
 drivers/pci/controller/dwc/pcie-tegra194.c | 27 +++++++++++++---------
 1 file changed, 16 insertions(+), 11 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index 5103995cd6c7..f048b2342af4 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -711,16 +711,27 @@ static void init_host_aspm(struct tegra_pcie_dw *pcie)
 	dw_pcie_writel_dbi(pci, PCIE_PORT_AFR, val);
 }
 
-static void init_debugfs(struct tegra_pcie_dw *pcie)
+static int init_debugfs(struct tegra_pcie_dw *pcie)
 {
-	debugfs_create_devm_seqfile(pcie->dev, "aspm_state_cnt", pcie->debugfs,
+	struct device *dev = pcie->dev;
+	char *name;
+
+	name = devm_kasprintf(dev, GFP_KERNEL, "%pOFP", dev->of_node);
+	if (!name)
+		return -ENOMEM;
+
+	pcie->debugfs = debugfs_create_dir(name, NULL);
+
+	debugfs_create_devm_seqfile(dev, "aspm_state_cnt", pcie->debugfs,
 				    aspm_state_cnt);
+
+	return 0;
 }
 #else
 static inline void disable_aspm_l12(struct tegra_pcie_dw *pcie) { return; }
 static inline void disable_aspm_l11(struct tegra_pcie_dw *pcie) { return; }
 static inline void init_host_aspm(struct tegra_pcie_dw *pcie) { return; }
-static inline void init_debugfs(struct tegra_pcie_dw *pcie) { return; }
+static inline int init_debugfs(struct tegra_pcie_dw *pcie) { return 0; }
 #endif
 
 static void tegra_pcie_enable_system_interrupts(struct dw_pcie_rp *pp)
@@ -1634,7 +1645,6 @@ static void tegra_pcie_deinit_controller(struct tegra_pcie_dw *pcie)
 static int tegra_pcie_config_rp(struct tegra_pcie_dw *pcie)
 {
 	struct device *dev = pcie->dev;
-	char *name;
 	int ret;
 
 	pm_runtime_enable(dev);
@@ -1664,14 +1674,9 @@ static int tegra_pcie_config_rp(struct tegra_pcie_dw *pcie)
 		goto fail_host_init;
 	}
 
-	name = devm_kasprintf(dev, GFP_KERNEL, "%pOFP", dev->of_node);
-	if (!name) {
-		ret = -ENOMEM;
+	ret = init_debugfs(pcie);
+	if (ret < 0)
 		goto fail_host_init;
-	}
-
-	pcie->debugfs = debugfs_create_dir(name, NULL);
-	init_debugfs(pcie);
 
 	return ret;
 

base-commit: a8662bcd2ff152bfbc751cab20f33053d74d0963
-- 
2.25.1

Re: [v2] PCI: tegra194: Fix debugfs directory creation when CONFIG_PCIEASPM is disabled

[Christophe JAILLET]

Le 06/04/2025 à 15:43, Hans Zhang a écrit :
> Previously, the debugfs directory was unconditionally created in
> tegra_pcie_config_rp() regardless of the CONFIG_PCIEASPM setting.
> This led to unnecessary directory creation when ASPM support was disabled.
> 
> Move the debugfs directory creation into init_debugfs() which is
> conditionally compiled based on CONFIG_PCIEASPM. This ensures:
> - The directory is only created when ASPM-related debugfs entries are
>    needed.
> - Proper error handling for directory creation failures.
> - Avoids cluttering debugfs with empty directories when ASPM is disabled.
> 
> Signed-off-by: Hans Zhang <18255117159-9Onoh4P/yGk@public.gmane.org>
> ---
> Changes since v1:
> https://lore.kernel.org/linux-pci/20250405145459.26800-1-18255117159-9Onoh4P/yGk@public.gmane.org
> 
> - The first version was committed incorrectly because the judgment
>    parameter in "debugfs_remove_recursive" was not noticed.
> ---
>   drivers/pci/controller/dwc/pcie-tegra194.c | 27 +++++++++++++---------
>   1 file changed, 16 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
> index 5103995cd6c7..f048b2342af4 100644
> --- a/drivers/pci/controller/dwc/pcie-tegra194.c
> +++ b/drivers/pci/controller/dwc/pcie-tegra194.c
> @@ -711,16 +711,27 @@ static void init_host_aspm(struct tegra_pcie_dw *pcie)
>   	dw_pcie_writel_dbi(pci, PCIE_PORT_AFR, val);
>   }
>   
> -static void init_debugfs(struct tegra_pcie_dw *pcie)
> +static int init_debugfs(struct tegra_pcie_dw *pcie)

I would keep it a void function.
If devm_kasprintf() fails, which is unlikely, then the module should 
still work correctly. So just a return; should be fine IMHO.

Usually, errors related to debugfs are silently ignored as is does not 
prevent this to work.

CJ

>   {
> -	debugfs_create_devm_seqfile(pcie->dev, "aspm_state_cnt", pcie->debugfs,
> +	struct device *dev = pcie->dev;
> +	char *name;
> +
> +	name = devm_kasprintf(dev, GFP_KERNEL, "%pOFP", dev->of_node);
> +	if (!name)
> +		return -ENOMEM;
> +
> +	pcie->debugfs = debugfs_create_dir(name, NULL);
> +
> +	debugfs_create_devm_seqfile(dev, "aspm_state_cnt", pcie->debugfs,
>   				    aspm_state_cnt);
> +
> +	return 0;
>   }
>   #else
>   static inline void disable_aspm_l12(struct tegra_pcie_dw *pcie) { return; }
>   static inline void disable_aspm_l11(struct tegra_pcie_dw *pcie) { return; }
>   static inline void init_host_aspm(struct tegra_pcie_dw *pcie) { return; }
> -static inline void init_debugfs(struct tegra_pcie_dw *pcie) { return; }
> +static inline int init_debugfs(struct tegra_pcie_dw *pcie) { return 0; }
>   #endif
>   
>   static void tegra_pcie_enable_system_interrupts(struct dw_pcie_rp *pp)
> @@ -1634,7 +1645,6 @@ static void tegra_pcie_deinit_controller(struct tegra_pcie_dw *pcie)
>   static int tegra_pcie_config_rp(struct tegra_pcie_dw *pcie)
>   {
>   	struct device *dev = pcie->dev;
> -	char *name;
>   	int ret;
>   
>   	pm_runtime_enable(dev);
> @@ -1664,14 +1674,9 @@ static int tegra_pcie_config_rp(struct tegra_pcie_dw *pcie)
>   		goto fail_host_init;
>   	}
>   
> -	name = devm_kasprintf(dev, GFP_KERNEL, "%pOFP", dev->of_node);
> -	if (!name) {
> -		ret = -ENOMEM;
> +	ret = init_debugfs(pcie);
> +	if (ret < 0)
>   		goto fail_host_init;
> -	}
> -
> -	pcie->debugfs = debugfs_create_dir(name, NULL);
> -	init_debugfs(pcie);
>   
>   	return ret;
>   
> 
> base-commit: a8662bcd2ff152bfbc751cab20f33053d74d0963

Re: [v2] PCI: tegra194: Fix debugfs directory creation when CONFIG_PCIEASPM is disabled

[Hans Zhang]

On 2025/4/7 02:10, Christophe JAILLET wrote:
> Le 06/04/2025 à 15:43, Hans Zhang a écrit :
>> Previously, the debugfs directory was unconditionally created in
>> tegra_pcie_config_rp() regardless of the CONFIG_PCIEASPM setting.
>> This led to unnecessary directory creation when ASPM support was 
>> disabled.
>>
>> Move the debugfs directory creation into init_debugfs() which is
>> conditionally compiled based on CONFIG_PCIEASPM. This ensures:
>> - The directory is only created when ASPM-related debugfs entries are
>>    needed.
>> - Proper error handling for directory creation failures.
>> - Avoids cluttering debugfs with empty directories when ASPM is disabled.
>>
>> Signed-off-by: Hans Zhang <18255117159-9Onoh4P/yGk@public.gmane.org>
>> ---
>> Changes since v1:
>> https://lore.kernel.org/linux-pci/20250405145459.26800-1-18255117159-9Onoh4P/yGk@public.gmane.org
>>
>> - The first version was committed incorrectly because the judgment
>>    parameter in "debugfs_remove_recursive" was not noticed.
>> ---
>>   drivers/pci/controller/dwc/pcie-tegra194.c | 27 +++++++++++++---------
>>   1 file changed, 16 insertions(+), 11 deletions(-)
>>
>> diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c 
>> b/drivers/pci/controller/dwc/pcie-tegra194.c
>> index 5103995cd6c7..f048b2342af4 100644
>> --- a/drivers/pci/controller/dwc/pcie-tegra194.c
>> +++ b/drivers/pci/controller/dwc/pcie-tegra194.c
>> @@ -711,16 +711,27 @@ static void init_host_aspm(struct tegra_pcie_dw 
>> *pcie)
>>       dw_pcie_writel_dbi(pci, PCIE_PORT_AFR, val);
>>   }
>> -static void init_debugfs(struct tegra_pcie_dw *pcie)
>> +static int init_debugfs(struct tegra_pcie_dw *pcie)
> 
> I would keep it a void function.
> If devm_kasprintf() fails, which is unlikely, then the module should 
> still work correctly. So just a return; should be fine IMHO.
> 
> Usually, errors related to debugfs are silently ignored as is does not 
> prevent this to work.
> 

Hi Christophe,

Thanks your for reply. Will change.

Best regards,
Hans

> CJ
> 
>>   {
>> -    debugfs_create_devm_seqfile(pcie->dev, "aspm_state_cnt", 
>> pcie->debugfs,
>> +    struct device *dev = pcie->dev;
>> +    char *name;
>> +
>> +    name = devm_kasprintf(dev, GFP_KERNEL, "%pOFP", dev->of_node);
>> +    if (!name)
>> +        return -ENOMEM;
>> +
>> +    pcie->debugfs = debugfs_create_dir(name, NULL);
>> +
>> +    debugfs_create_devm_seqfile(dev, "aspm_state_cnt", pcie->debugfs,
>>                       aspm_state_cnt);
>> +
>> +    return 0;
>>   }
>>   #else
>>   static inline void disable_aspm_l12(struct tegra_pcie_dw *pcie) { 
>> return; }
>>   static inline void disable_aspm_l11(struct tegra_pcie_dw *pcie) { 
>> return; }
>>   static inline void init_host_aspm(struct tegra_pcie_dw *pcie) { 
>> return; }
>> -static inline void init_debugfs(struct tegra_pcie_dw *pcie) { return; }
>> +static inline int init_debugfs(struct tegra_pcie_dw *pcie) { return 0; }
>>   #endif
>>   static void tegra_pcie_enable_system_interrupts(struct dw_pcie_rp *pp)
>> @@ -1634,7 +1645,6 @@ static void tegra_pcie_deinit_controller(struct 
>> tegra_pcie_dw *pcie)
>>   static int tegra_pcie_config_rp(struct tegra_pcie_dw *pcie)
>>   {
>>       struct device *dev = pcie->dev;
>> -    char *name;
>>       int ret;
>>       pm_runtime_enable(dev);
>> @@ -1664,14 +1674,9 @@ static int tegra_pcie_config_rp(struct 
>> tegra_pcie_dw *pcie)
>>           goto fail_host_init;
>>       }
>> -    name = devm_kasprintf(dev, GFP_KERNEL, "%pOFP", dev->of_node);
>> -    if (!name) {
>> -        ret = -ENOMEM;
>> +    ret = init_debugfs(pcie);
>> +    if (ret < 0)
>>           goto fail_host_init;
>> -    }
>> -
>> -    pcie->debugfs = debugfs_create_dir(name, NULL);
>> -    init_debugfs(pcie);
>>       return ret;
>>
>> base-commit: a8662bcd2ff152bfbc751cab20f33053d74d0963