[PATCH 01/23] interconnect: fix mem leak when freeing nodes

[PATCH 01/23] interconnect: fix mem leak when freeing nodes

[Johan Hovold]

The node link array is allocated when adding links to a node but is not
deallocated when nodes are destroyed.

Fixes: 11f1ceca7031 ("interconnect: Add generic on-chip interconnect API")
Cc: stable@vger.kernel.org      # 5.1
Cc: Georgi Djakov <georgi.djakov@linaro.org>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 drivers/interconnect/core.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c
index 423f875d4b54..dc61620a0191 100644
--- a/drivers/interconnect/core.c
+++ b/drivers/interconnect/core.c
@@ -850,6 +850,7 @@ void icc_node_destroy(int id)
 
 	mutex_unlock(&icc_lock);
 
+	kfree(node->links);
 	kfree(node);
 }
 EXPORT_SYMBOL_GPL(icc_node_destroy);
-- 
2.39.1

Re: [PATCH 01/23] interconnect: fix mem leak when freeing nodes

[Konrad Dybcio]

On 1.02.2023 11:15, Johan Hovold wrote:
> The node link array is allocated when adding links to a node but is not
> deallocated when nodes are destroyed.
> 
> Fixes: 11f1ceca7031 ("interconnect: Add generic on-chip interconnect API")
> Cc: stable@vger.kernel.org      # 5.1
> Cc: Georgi Djakov <georgi.djakov@linaro.org>
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>

Konrad
>  drivers/interconnect/core.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c
> index 423f875d4b54..dc61620a0191 100644
> --- a/drivers/interconnect/core.c
> +++ b/drivers/interconnect/core.c
> @@ -850,6 +850,7 @@ void icc_node_destroy(int id)
>  
>  	mutex_unlock(&icc_lock);
>  
> +	kfree(node->links);
>  	kfree(node);
>  }
>  EXPORT_SYMBOL_GPL(icc_node_destroy);

[PATCH 02/23] interconnect: fix icc_provider_del() error handling

[Johan Hovold]

The interconnect framework currently expects that providers are only
removed when there are no users and after all nodes have been removed.

There is currently nothing that guarantees this to be the case and the
framework does not do any reference counting, but refusing to remove the
provider is never correct as that would leave a dangling pointer to a
resource that is about to be released in the global provider list (e.g.
accessible through debugfs).

Replace the current sanity checks with WARN_ON() so that the provider is
always removed.

Fixes: 11f1ceca7031 ("interconnect: Add generic on-chip interconnect API")
Cc: stable@vger.kernel.org      # 5.1: 680f8666baf6: interconnect: Make icc_provider_del() return void
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 drivers/interconnect/core.c | 14 ++------------
 1 file changed, 2 insertions(+), 12 deletions(-)

diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c
index dc61620a0191..43c5c8503ee8 100644
--- a/drivers/interconnect/core.c
+++ b/drivers/interconnect/core.c
@@ -1062,18 +1062,8 @@ EXPORT_SYMBOL_GPL(icc_provider_add);
 void icc_provider_del(struct icc_provider *provider)
 {
 	mutex_lock(&icc_lock);
-	if (provider->users) {
-		pr_warn("interconnect provider still has %d users\n",
-			provider->users);
-		mutex_unlock(&icc_lock);
-		return;
-	}
-
-	if (!list_empty(&provider->nodes)) {
-		pr_warn("interconnect provider still has nodes\n");
-		mutex_unlock(&icc_lock);
-		return;
-	}
+	WARN_ON(provider->users);
+	WARN_ON(!list_empty(&provider->nodes));
 
 	list_del(&provider->provider_list);
 	mutex_unlock(&icc_lock);
-- 
2.39.1

Re: [PATCH 02/23] interconnect: fix icc_provider_del() error handling

[Konrad Dybcio]

On 1.02.2023 11:15, Johan Hovold wrote:
> The interconnect framework currently expects that providers are only
> removed when there are no users and after all nodes have been removed.
> 
> There is currently nothing that guarantees this to be the case and the
> framework does not do any reference counting, but refusing to remove the
> provider is never correct as that would leave a dangling pointer to a
> resource that is about to be released in the global provider list (e.g.
> accessible through debugfs).
> 
> Replace the current sanity checks with WARN_ON() so that the provider is
> always removed.
I spent a considerable amount of time scratching my head what WARN_ON has
to do with removing list items.. I suppose "don't return early and replace
pr_warn with WARN_ON" would have been clearer, but maybe that's just me
in the morning..

> 
> Fixes: 11f1ceca7031 ("interconnect: Add generic on-chip interconnect API")
> Cc: stable@vger.kernel.org      # 5.1: 680f8666baf6: interconnect: Make icc_provider_del() return void
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>

Konrad
>  drivers/interconnect/core.c | 14 ++------------
>  1 file changed, 2 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c
> index dc61620a0191..43c5c8503ee8 100644
> --- a/drivers/interconnect/core.c
> +++ b/drivers/interconnect/core.c
> @@ -1062,18 +1062,8 @@ EXPORT_SYMBOL_GPL(icc_provider_add);
>  void icc_provider_del(struct icc_provider *provider)
>  {
>  	mutex_lock(&icc_lock);
> -	if (provider->users) {
> -		pr_warn("interconnect provider still has %d users\n",
> -			provider->users);
> -		mutex_unlock(&icc_lock);
> -		return;
> -	}
> -
> -	if (!list_empty(&provider->nodes)) {
> -		pr_warn("interconnect provider still has nodes\n");
> -		mutex_unlock(&icc_lock);
> -		return;
> -	}
> +	WARN_ON(provider->users);
> +	WARN_ON(!list_empty(&provider->nodes));
>  
>  	list_del(&provider->provider_list);
>  	mutex_unlock(&icc_lock);

[PATCH 03/23] interconnect: fix provider registration API

[Johan Hovold]

The current interconnect provider interface is inherently racy as
providers are expected to be added before being fully initialised.

Specifically, nodes are currently not added and the provider data is not
initialised until after registering the provider which can cause racing
DT lookups to fail.

Add a new provider API which will be used to fix up the interconnect
drivers.

The old API is reimplemented using the new interface and will be removed
once all drivers have been fixed.

Fixes: 11f1ceca7031 ("interconnect: Add generic on-chip interconnect API")
Fixes: 87e3031b6fbd ("interconnect: Allow endpoints translation via DT")
Cc: stable@vger.kernel.org      # 5.1
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 drivers/interconnect/core.c           | 52 +++++++++++++++++++--------
 include/linux/interconnect-provider.h | 12 +++++++
 2 files changed, 50 insertions(+), 14 deletions(-)

diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c
index 43c5c8503ee8..93d27ff8eef6 100644
--- a/drivers/interconnect/core.c
+++ b/drivers/interconnect/core.c
@@ -1030,44 +1030,68 @@ int icc_nodes_remove(struct icc_provider *provider)
 EXPORT_SYMBOL_GPL(icc_nodes_remove);
 
 /**
- * icc_provider_add() - add a new interconnect provider
- * @provider: the interconnect provider that will be added into topology
+ * icc_provider_init() - initialize a new interconnect provider
+ * @provider: the interconnect provider to initialize
+ *
+ * Must be called before adding nodes to the provider.
+ */
+void icc_provider_init(struct icc_provider *provider)
+{
+	WARN_ON(!provider->set);
+
+	INIT_LIST_HEAD(&provider->nodes);
+}
+EXPORT_SYMBOL_GPL(icc_provider_init);
+
+/**
+ * icc_provider_register() - register a new interconnect provider
+ * @provider: the interconnect provider to register
  *
  * Return: 0 on success, or an error code otherwise
  */
-int icc_provider_add(struct icc_provider *provider)
+int icc_provider_register(struct icc_provider *provider)
 {
-	if (WARN_ON(!provider->set))
-		return -EINVAL;
 	if (WARN_ON(!provider->xlate && !provider->xlate_extended))
 		return -EINVAL;
 
 	mutex_lock(&icc_lock);
-
-	INIT_LIST_HEAD(&provider->nodes);
 	list_add_tail(&provider->provider_list, &icc_providers);
-
 	mutex_unlock(&icc_lock);
 
-	dev_dbg(provider->dev, "interconnect provider added to topology\n");
+	dev_dbg(provider->dev, "interconnect provider registered\n");
 
 	return 0;
 }
-EXPORT_SYMBOL_GPL(icc_provider_add);
+EXPORT_SYMBOL_GPL(icc_provider_register);
 
 /**
- * icc_provider_del() - delete previously added interconnect provider
- * @provider: the interconnect provider that will be removed from topology
+ * icc_provider_deregister() - deregister an interconnect provider
+ * @provider: the interconnect provider to deregister
  */
-void icc_provider_del(struct icc_provider *provider)
+void icc_provider_deregister(struct icc_provider *provider)
 {
 	mutex_lock(&icc_lock);
 	WARN_ON(provider->users);
-	WARN_ON(!list_empty(&provider->nodes));
 
 	list_del(&provider->provider_list);
 	mutex_unlock(&icc_lock);
 }
+EXPORT_SYMBOL_GPL(icc_provider_deregister);
+
+int icc_provider_add(struct icc_provider *provider)
+{
+	icc_provider_init(provider);
+
+	return icc_provider_register(provider);
+}
+EXPORT_SYMBOL_GPL(icc_provider_add);
+
+void icc_provider_del(struct icc_provider *provider)
+{
+	WARN_ON(!list_empty(&provider->nodes));
+
+	icc_provider_deregister(provider);
+}
 EXPORT_SYMBOL_GPL(icc_provider_del);
 
 static const struct of_device_id __maybe_unused ignore_list[] = {
diff --git a/include/linux/interconnect-provider.h b/include/linux/interconnect-provider.h
index cd5c5a27557f..d12cd18aab3f 100644
--- a/include/linux/interconnect-provider.h
+++ b/include/linux/interconnect-provider.h
@@ -122,6 +122,9 @@ int icc_link_destroy(struct icc_node *src, struct icc_node *dst);
 void icc_node_add(struct icc_node *node, struct icc_provider *provider);
 void icc_node_del(struct icc_node *node);
 int icc_nodes_remove(struct icc_provider *provider);
+void icc_provider_init(struct icc_provider *provider);
+int icc_provider_register(struct icc_provider *provider);
+void icc_provider_deregister(struct icc_provider *provider);
 int icc_provider_add(struct icc_provider *provider);
 void icc_provider_del(struct icc_provider *provider);
 struct icc_node_data *of_icc_get_from_provider(struct of_phandle_args *spec);
@@ -167,6 +170,15 @@ static inline int icc_nodes_remove(struct icc_provider *provider)
 	return -ENOTSUPP;
 }
 
+static inline void icc_provider_init(struct icc_provider *provider) { }
+
+static inline int icc_provider_register(struct icc_provider *provider)
+{
+	return -ENOTSUPP;
+}
+
+static inline void icc_provider_deregister(struct icc_provider *provider) { }
+
 static inline int icc_provider_add(struct icc_provider *provider)
 {
 	return -ENOTSUPP;
-- 
2.39.1

Re: [PATCH 03/23] interconnect: fix provider registration API

[Konrad Dybcio]

On 1.02.2023 11:15, Johan Hovold wrote:
> The current interconnect provider interface is inherently racy as
> providers are expected to be added before being fully initialised.
> 
> Specifically, nodes are currently not added and the provider data is not
> initialised until after registering the provider which can cause racing
> DT lookups to fail.
> 
> Add a new provider API which will be used to fix up the interconnect
> drivers.
> 
> The old API is reimplemented using the new interface and will be removed
> once all drivers have been fixed.
> 
> Fixes: 11f1ceca7031 ("interconnect: Add generic on-chip interconnect API")
> Fixes: 87e3031b6fbd ("interconnect: Allow endpoints translation via DT")
> Cc: stable@vger.kernel.org      # 5.1
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>

Konrad
>  drivers/interconnect/core.c           | 52 +++++++++++++++++++--------
>  include/linux/interconnect-provider.h | 12 +++++++
>  2 files changed, 50 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c
> index 43c5c8503ee8..93d27ff8eef6 100644
> --- a/drivers/interconnect/core.c
> +++ b/drivers/interconnect/core.c
> @@ -1030,44 +1030,68 @@ int icc_nodes_remove(struct icc_provider *provider)
>  EXPORT_SYMBOL_GPL(icc_nodes_remove);
>  
>  /**
> - * icc_provider_add() - add a new interconnect provider
> - * @provider: the interconnect provider that will be added into topology
> + * icc_provider_init() - initialize a new interconnect provider
> + * @provider: the interconnect provider to initialize
> + *
> + * Must be called before adding nodes to the provider.
> + */
> +void icc_provider_init(struct icc_provider *provider)
> +{
> +	WARN_ON(!provider->set);
> +
> +	INIT_LIST_HEAD(&provider->nodes);
> +}
> +EXPORT_SYMBOL_GPL(icc_provider_init);
> +
> +/**
> + * icc_provider_register() - register a new interconnect provider
> + * @provider: the interconnect provider to register
>   *
>   * Return: 0 on success, or an error code otherwise
>   */
> -int icc_provider_add(struct icc_provider *provider)
> +int icc_provider_register(struct icc_provider *provider)
>  {
> -	if (WARN_ON(!provider->set))
> -		return -EINVAL;
>  	if (WARN_ON(!provider->xlate && !provider->xlate_extended))
>  		return -EINVAL;
>  
>  	mutex_lock(&icc_lock);
> -
> -	INIT_LIST_HEAD(&provider->nodes);
>  	list_add_tail(&provider->provider_list, &icc_providers);
> -
>  	mutex_unlock(&icc_lock);
>  
> -	dev_dbg(provider->dev, "interconnect provider added to topology\n");
> +	dev_dbg(provider->dev, "interconnect provider registered\n");
>  
>  	return 0;
>  }
> -EXPORT_SYMBOL_GPL(icc_provider_add);
> +EXPORT_SYMBOL_GPL(icc_provider_register);
>  
>  /**
> - * icc_provider_del() - delete previously added interconnect provider
> - * @provider: the interconnect provider that will be removed from topology
> + * icc_provider_deregister() - deregister an interconnect provider
> + * @provider: the interconnect provider to deregister
>   */
> -void icc_provider_del(struct icc_provider *provider)
> +void icc_provider_deregister(struct icc_provider *provider)
>  {
>  	mutex_lock(&icc_lock);
>  	WARN_ON(provider->users);
> -	WARN_ON(!list_empty(&provider->nodes));
>  
>  	list_del(&provider->provider_list);
>  	mutex_unlock(&icc_lock);
>  }
> +EXPORT_SYMBOL_GPL(icc_provider_deregister);
> +
> +int icc_provider_add(struct icc_provider *provider)
> +{
> +	icc_provider_init(provider);
> +
> +	return icc_provider_register(provider);
> +}
> +EXPORT_SYMBOL_GPL(icc_provider_add);
> +
> +void icc_provider_del(struct icc_provider *provider)
> +{
> +	WARN_ON(!list_empty(&provider->nodes));
> +
> +	icc_provider_deregister(provider);
> +}
>  EXPORT_SYMBOL_GPL(icc_provider_del);
>  
>  static const struct of_device_id __maybe_unused ignore_list[] = {
> diff --git a/include/linux/interconnect-provider.h b/include/linux/interconnect-provider.h
> index cd5c5a27557f..d12cd18aab3f 100644
> --- a/include/linux/interconnect-provider.h
> +++ b/include/linux/interconnect-provider.h
> @@ -122,6 +122,9 @@ int icc_link_destroy(struct icc_node *src, struct icc_node *dst);
>  void icc_node_add(struct icc_node *node, struct icc_provider *provider);
>  void icc_node_del(struct icc_node *node);
>  int icc_nodes_remove(struct icc_provider *provider);
> +void icc_provider_init(struct icc_provider *provider);
> +int icc_provider_register(struct icc_provider *provider);
> +void icc_provider_deregister(struct icc_provider *provider);
>  int icc_provider_add(struct icc_provider *provider);
>  void icc_provider_del(struct icc_provider *provider);
>  struct icc_node_data *of_icc_get_from_provider(struct of_phandle_args *spec);
> @@ -167,6 +170,15 @@ static inline int icc_nodes_remove(struct icc_provider *provider)
>  	return -ENOTSUPP;
>  }
>  
> +static inline void icc_provider_init(struct icc_provider *provider) { }
> +
> +static inline int icc_provider_register(struct icc_provider *provider)
> +{
> +	return -ENOTSUPP;
> +}
> +
> +static inline void icc_provider_deregister(struct icc_provider *provider) { }
> +
>  static inline int icc_provider_add(struct icc_provider *provider)
>  {
>  	return -ENOTSUPP;

[PATCH 04/23] interconnect: imx: fix registration race

[Johan Hovold]

The current interconnect provider registration interface is inherently
racy as nodes are not added until the after adding the provider. This
can specifically cause racing DT lookups to fail.

Switch to using the new API where the provider is not registered until
after it has been fully initialised.

Fixes: f0d8048525d7 ("interconnect: Add imx core driver")
Cc: stable@vger.kernel.org      # 5.8
Cc: Leonard Crestez <leonard.crestez@nxp.com>
Cc: Alexandre Bailon <abailon@baylibre.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 drivers/interconnect/imx/imx.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/interconnect/imx/imx.c b/drivers/interconnect/imx/imx.c
index 823d9be9771a..979ed610f704 100644
--- a/drivers/interconnect/imx/imx.c
+++ b/drivers/interconnect/imx/imx.c
@@ -295,6 +295,9 @@ int imx_icc_register(struct platform_device *pdev,
 	provider->xlate = of_icc_xlate_onecell;
 	provider->data = data;
 	provider->dev = dev->parent;
+
+	icc_provider_init(provider);
+
 	platform_set_drvdata(pdev, imx_provider);
 
 	if (settings) {
@@ -306,20 +309,18 @@ int imx_icc_register(struct platform_device *pdev,
 		}
 	}
 
-	ret = icc_provider_add(provider);
-	if (ret) {
-		dev_err(dev, "error adding interconnect provider: %d\n", ret);
+	ret = imx_icc_register_nodes(imx_provider, nodes, nodes_count, settings);
+	if (ret)
 		return ret;
-	}
 
-	ret = imx_icc_register_nodes(imx_provider, nodes, nodes_count, settings);
+	ret = icc_provider_register(provider);
 	if (ret)
-		goto provider_del;
+		goto err_unregister_nodes;
 
 	return 0;
 
-provider_del:
-	icc_provider_del(provider);
+err_unregister_nodes:
+	imx_icc_unregister_nodes(&imx_provider->provider);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(imx_icc_register);
@@ -328,9 +329,8 @@ void imx_icc_unregister(struct platform_device *pdev)
 {
 	struct imx_icc_provider *imx_provider = platform_get_drvdata(pdev);
 
+	icc_provider_deregister(&imx_provider->provider);
 	imx_icc_unregister_nodes(&imx_provider->provider);
-
-	icc_provider_del(&imx_provider->provider);
 }
 EXPORT_SYMBOL_GPL(imx_icc_unregister);
 
-- 
2.39.1

Re: [PATCH 04/23] interconnect: imx: fix registration race

[Konrad Dybcio]

On 1.02.2023 11:15, Johan Hovold wrote:
> The current interconnect provider registration interface is inherently
> racy as nodes are not added until the after adding the provider. This
> can specifically cause racing DT lookups to fail.
> 
> Switch to using the new API where the provider is not registered until
> after it has been fully initialised.
> 
> Fixes: f0d8048525d7 ("interconnect: Add imx core driver")
> Cc: stable@vger.kernel.org      # 5.8
> Cc: Leonard Crestez <leonard.crestez@nxp.com>
> Cc: Alexandre Bailon <abailon@baylibre.com>
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>

Konrad
>  drivers/interconnect/imx/imx.c | 20 ++++++++++----------
>  1 file changed, 10 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/interconnect/imx/imx.c b/drivers/interconnect/imx/imx.c
> index 823d9be9771a..979ed610f704 100644
> --- a/drivers/interconnect/imx/imx.c
> +++ b/drivers/interconnect/imx/imx.c
> @@ -295,6 +295,9 @@ int imx_icc_register(struct platform_device *pdev,
>  	provider->xlate = of_icc_xlate_onecell;
>  	provider->data = data;
>  	provider->dev = dev->parent;
> +
> +	icc_provider_init(provider);
> +
>  	platform_set_drvdata(pdev, imx_provider);
>  
>  	if (settings) {
> @@ -306,20 +309,18 @@ int imx_icc_register(struct platform_device *pdev,
>  		}
>  	}
>  
> -	ret = icc_provider_add(provider);
> -	if (ret) {
> -		dev_err(dev, "error adding interconnect provider: %d\n", ret);
> +	ret = imx_icc_register_nodes(imx_provider, nodes, nodes_count, settings);
> +	if (ret)
>  		return ret;
> -	}
>  
> -	ret = imx_icc_register_nodes(imx_provider, nodes, nodes_count, settings);
> +	ret = icc_provider_register(provider);
>  	if (ret)
> -		goto provider_del;
> +		goto err_unregister_nodes;
>  
>  	return 0;
>  
> -provider_del:
> -	icc_provider_del(provider);
> +err_unregister_nodes:
> +	imx_icc_unregister_nodes(&imx_provider->provider);
>  	return ret;
>  }
>  EXPORT_SYMBOL_GPL(imx_icc_register);
> @@ -328,9 +329,8 @@ void imx_icc_unregister(struct platform_device *pdev)
>  {
>  	struct imx_icc_provider *imx_provider = platform_get_drvdata(pdev);
>  
> +	icc_provider_deregister(&imx_provider->provider);
>  	imx_icc_unregister_nodes(&imx_provider->provider);
> -
> -	icc_provider_del(&imx_provider->provider);
>  }
>  EXPORT_SYMBOL_GPL(imx_icc_unregister);
>  

Re: [PATCH 04/23] interconnect: imx: fix registration race

[Luca Ceresoli]

Hello Johan,

On Wed,  1 Feb 2023 11:15:40 +0100
Johan Hovold <johan+linaro@kernel.org> wrote:

> The current interconnect provider registration interface is inherently
> racy as nodes are not added until the after adding the provider. This
> can specifically cause racing DT lookups to fail.
> 
> Switch to using the new API where the provider is not registered until
> after it has been fully initialised.
> 
> Fixes: f0d8048525d7 ("interconnect: Add imx core driver")
> Cc: stable@vger.kernel.org      # 5.8
> Cc: Leonard Crestez <leonard.crestez@nxp.com>
> Cc: Alexandre Bailon <abailon@baylibre.com>
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>

Georgi pointed me to this series after I reported a bug yesterday [0],
that I found on iMX8MP. So I ran some tests with my original, failing
tree, minus one patch with my debugging code to hunt for the bug, plus
patches 1-4 of this series.

The original code was failing approx 5~10% of the times. With your 4
patches applied it ran 139 times with zero errors, which looks great! I
won't be able to do more testing until next Monday to be extra sure.

[0]
https://lore.kernel.org/linux-arm-kernel/20230202175525.3dba79a7@booty/T/#u

-- 
Luca Ceresoli, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

Re: [PATCH 04/23] interconnect: imx: fix registration race

[Johan Hovold]

On Fri, Feb 03, 2023 at 05:01:21PM +0100, Luca Ceresoli wrote:
> Hello Johan,
> 
> On Wed,  1 Feb 2023 11:15:40 +0100
> Johan Hovold <johan+linaro@kernel.org> wrote:
> 
> > The current interconnect provider registration interface is inherently
> > racy as nodes are not added until the after adding the provider. This
> > can specifically cause racing DT lookups to fail.
> > 
> > Switch to using the new API where the provider is not registered until
> > after it has been fully initialised.
> > 
> > Fixes: f0d8048525d7 ("interconnect: Add imx core driver")
> > Cc: stable@vger.kernel.org      # 5.8
> > Cc: Leonard Crestez <leonard.crestez@nxp.com>
> > Cc: Alexandre Bailon <abailon@baylibre.com>
> > Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> 
> Georgi pointed me to this series after I reported a bug yesterday [0],
> that I found on iMX8MP. So I ran some tests with my original, failing
> tree, minus one patch with my debugging code to hunt for the bug, plus
> patches 1-4 of this series.
> 
> The original code was failing approx 5~10% of the times. With your 4
> patches applied it ran 139 times with zero errors, which looks great! I
> won't be able to do more testing until next Monday to be extra sure.

Thanks for testing.

It indeed looks like you're hitting the same race, and as the imx
interconnect driver also initialises the provider data num_nodes count
before adding the nodes it results in that NULL-deref (where the qcom
driver failed a bit more gracefully).

Johan

> [0]
> https://lore.kernel.org/linux-arm-kernel/20230202175525.3dba79a7@booty/T/#u

Re: [PATCH 04/23] interconnect: imx: fix registration race

[Luca Ceresoli]

Hello Johan,

On Mon, 6 Feb 2023 09:09:50 +0100
Johan Hovold <johan@kernel.org> wrote:

> On Fri, Feb 03, 2023 at 05:01:21PM +0100, Luca Ceresoli wrote:
> > Hello Johan,
> > 
> > On Wed,  1 Feb 2023 11:15:40 +0100
> > Johan Hovold <johan+linaro@kernel.org> wrote:
> >   
> > > The current interconnect provider registration interface is inherently
> > > racy as nodes are not added until the after adding the provider. This
> > > can specifically cause racing DT lookups to fail.
> > > 
> > > Switch to using the new API where the provider is not registered until
> > > after it has been fully initialised.
> > > 
> > > Fixes: f0d8048525d7 ("interconnect: Add imx core driver")
> > > Cc: stable@vger.kernel.org      # 5.8
> > > Cc: Leonard Crestez <leonard.crestez@nxp.com>
> > > Cc: Alexandre Bailon <abailon@baylibre.com>
> > > Signed-off-by: Johan Hovold <johan+linaro@kernel.org>  
> > 
> > Georgi pointed me to this series after I reported a bug yesterday [0],
> > that I found on iMX8MP. So I ran some tests with my original, failing
> > tree, minus one patch with my debugging code to hunt for the bug, plus
> > patches 1-4 of this series.
> > 
> > The original code was failing approx 5~10% of the times. With your 4
> > patches applied it ran 139 times with zero errors, which looks great! I
> > won't be able to do more testing until next Monday to be extra sure.  
> 
> Thanks for testing.
> 
> It indeed looks like you're hitting the same race, and as the imx
> interconnect driver also initialises the provider data num_nodes count
> before adding the nodes it results in that NULL-deref (where the qcom
> driver failed a bit more gracefully).

My v6.2-rc5 tree with patches 1 to 4 added has booted 590 times with 0
errors, which add to the 139 times on Friday. This definitely deserves
my:

Tested-by: Luca Ceresoli <luca.ceresoli@bootlin.com>

-- 
Luca Ceresoli, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

[PATCH 05/23] interconnect: qcom: osm-l3: fix registration race

[Johan Hovold]

The current interconnect provider registration interface is inherently
racy as nodes are not added until the after adding the provider. This
can specifically cause racing DT lookups to fail:

	of_icc_xlate_onecell: invalid index 0
	cpu cpu0: error -EINVAL: error finding src node
	cpu cpu0: dev_pm_opp_of_find_icc_paths: Unable to get path0: -22
	qcom-cpufreq-hw: probe of 18591000.cpufreq failed with error -22

Switch to using the new API where the provider is not registered until
after it has been fully initialised.

Fixes: 5bc9900addaf ("interconnect: qcom: Add OSM L3 interconnect provider support")
Cc: stable@vger.kernel.org      # 5.7
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 drivers/interconnect/qcom/osm-l3.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/drivers/interconnect/qcom/osm-l3.c b/drivers/interconnect/qcom/osm-l3.c
index 5fa171087425..3a1cbfe3e481 100644
--- a/drivers/interconnect/qcom/osm-l3.c
+++ b/drivers/interconnect/qcom/osm-l3.c
@@ -158,8 +158,8 @@ static int qcom_osm_l3_remove(struct platform_device *pdev)
 {
 	struct qcom_osm_l3_icc_provider *qp = platform_get_drvdata(pdev);
 
+	icc_provider_deregister(&qp->provider);
 	icc_nodes_remove(&qp->provider);
-	icc_provider_del(&qp->provider);
 
 	return 0;
 }
@@ -245,14 +245,9 @@ static int qcom_osm_l3_probe(struct platform_device *pdev)
 	provider->set = qcom_osm_l3_set;
 	provider->aggregate = icc_std_aggregate;
 	provider->xlate = of_icc_xlate_onecell;
-	INIT_LIST_HEAD(&provider->nodes);
 	provider->data = data;
 
-	ret = icc_provider_add(provider);
-	if (ret) {
-		dev_err(&pdev->dev, "error adding interconnect provider\n");
-		return ret;
-	}
+	icc_provider_init(provider);
 
 	for (i = 0; i < num_nodes; i++) {
 		size_t j;
@@ -275,12 +270,15 @@ static int qcom_osm_l3_probe(struct platform_device *pdev)
 	}
 	data->num_nodes = num_nodes;
 
+	ret = icc_provider_register(provider);
+	if (ret)
+		goto err;
+
 	platform_set_drvdata(pdev, qp);
 
 	return 0;
 err:
 	icc_nodes_remove(provider);
-	icc_provider_del(provider);
 
 	return ret;
 }
-- 
2.39.1

Re: [PATCH 05/23] interconnect: qcom: osm-l3: fix registration race

[Konrad Dybcio]

On 1.02.2023 11:15, Johan Hovold wrote:
> The current interconnect provider registration interface is inherently
> racy as nodes are not added until the after adding the provider. This
> can specifically cause racing DT lookups to fail:
> 
> 	of_icc_xlate_onecell: invalid index 0
> 	cpu cpu0: error -EINVAL: error finding src node
> 	cpu cpu0: dev_pm_opp_of_find_icc_paths: Unable to get path0: -22
> 	qcom-cpufreq-hw: probe of 18591000.cpufreq failed with error -22
> 
> Switch to using the new API where the provider is not registered until
> after it has been fully initialised.
> 
> Fixes: 5bc9900addaf ("interconnect: qcom: Add OSM L3 interconnect provider support")
> Cc: stable@vger.kernel.org      # 5.7
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>

Konrad
>  drivers/interconnect/qcom/osm-l3.c | 14 ++++++--------
>  1 file changed, 6 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/interconnect/qcom/osm-l3.c b/drivers/interconnect/qcom/osm-l3.c
> index 5fa171087425..3a1cbfe3e481 100644
> --- a/drivers/interconnect/qcom/osm-l3.c
> +++ b/drivers/interconnect/qcom/osm-l3.c
> @@ -158,8 +158,8 @@ static int qcom_osm_l3_remove(struct platform_device *pdev)
>  {
>  	struct qcom_osm_l3_icc_provider *qp = platform_get_drvdata(pdev);
>  
> +	icc_provider_deregister(&qp->provider);
>  	icc_nodes_remove(&qp->provider);
> -	icc_provider_del(&qp->provider);
>  
>  	return 0;
>  }
> @@ -245,14 +245,9 @@ static int qcom_osm_l3_probe(struct platform_device *pdev)
>  	provider->set = qcom_osm_l3_set;
>  	provider->aggregate = icc_std_aggregate;
>  	provider->xlate = of_icc_xlate_onecell;
> -	INIT_LIST_HEAD(&provider->nodes);
>  	provider->data = data;
>  
> -	ret = icc_provider_add(provider);
> -	if (ret) {
> -		dev_err(&pdev->dev, "error adding interconnect provider\n");
> -		return ret;
> -	}
> +	icc_provider_init(provider);
>  
>  	for (i = 0; i < num_nodes; i++) {
>  		size_t j;
> @@ -275,12 +270,15 @@ static int qcom_osm_l3_probe(struct platform_device *pdev)
>  	}
>  	data->num_nodes = num_nodes;
>  
> +	ret = icc_provider_register(provider);
> +	if (ret)
> +		goto err;
> +
>  	platform_set_drvdata(pdev, qp);
>  
>  	return 0;
>  err:
>  	icc_nodes_remove(provider);
> -	icc_provider_del(provider);
>  
>  	return ret;
>  }

[PATCH 06/23] interconnect: qcom: rpm: fix probe child-node error handling

[Johan Hovold]

Make sure to clean up and release resources properly also in case probe
fails when populating child devices.

Fixes: e39bf2972c6e ("interconnect: icc-rpm: Support child NoC device probe")
Cc: stable@vger.kernel.org      # 5.17
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 drivers/interconnect/qcom/icc-rpm.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/interconnect/qcom/icc-rpm.c b/drivers/interconnect/qcom/icc-rpm.c
index df3196f72536..91778cfcbc65 100644
--- a/drivers/interconnect/qcom/icc-rpm.c
+++ b/drivers/interconnect/qcom/icc-rpm.c
@@ -541,8 +541,11 @@ int qnoc_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, qp);
 
 	/* Populate child NoC devices if any */
-	if (of_get_child_count(dev->of_node) > 0)
-		return of_platform_populate(dev->of_node, NULL, NULL, dev);
+	if (of_get_child_count(dev->of_node) > 0) {
+		ret = of_platform_populate(dev->of_node, NULL, NULL, dev);
+		if (ret)
+			goto err;
+	}
 
 	return 0;
 err:
-- 
2.39.1

Re: [PATCH 06/23] interconnect: qcom: rpm: fix probe child-node error handling

[Konrad Dybcio]

On 1.02.2023 11:15, Johan Hovold wrote:
> Make sure to clean up and release resources properly also in case probe
> fails when populating child devices.
> 
> Fixes: e39bf2972c6e ("interconnect: icc-rpm: Support child NoC device probe")
> Cc: stable@vger.kernel.org      # 5.17
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>

Konrad
>  drivers/interconnect/qcom/icc-rpm.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/interconnect/qcom/icc-rpm.c b/drivers/interconnect/qcom/icc-rpm.c
> index df3196f72536..91778cfcbc65 100644
> --- a/drivers/interconnect/qcom/icc-rpm.c
> +++ b/drivers/interconnect/qcom/icc-rpm.c
> @@ -541,8 +541,11 @@ int qnoc_probe(struct platform_device *pdev)
>  	platform_set_drvdata(pdev, qp);
>  
>  	/* Populate child NoC devices if any */
> -	if (of_get_child_count(dev->of_node) > 0)
> -		return of_platform_populate(dev->of_node, NULL, NULL, dev);
> +	if (of_get_child_count(dev->of_node) > 0) {
> +		ret = of_platform_populate(dev->of_node, NULL, NULL, dev);
> +		if (ret)
> +			goto err;
> +	}
>  
>  	return 0;
>  err:

[PATCH 07/23] interconnect: qcom: rpm: fix probe PM domain error handling

[Johan Hovold]

Make sure to disable clocks also in case attaching the power domain
fails.

Fixes: 7de109c0abe9 ("interconnect: icc-rpm: Add support for bus power domain")
Cc: stable@vger.kernel.org      # 5.17
Cc: Yassine Oudjana <y.oudjana@protonmail.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 drivers/interconnect/qcom/icc-rpm.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/interconnect/qcom/icc-rpm.c b/drivers/interconnect/qcom/icc-rpm.c
index 91778cfcbc65..da595059cafd 100644
--- a/drivers/interconnect/qcom/icc-rpm.c
+++ b/drivers/interconnect/qcom/icc-rpm.c
@@ -498,8 +498,7 @@ int qnoc_probe(struct platform_device *pdev)
 
 	if (desc->has_bus_pd) {
 		ret = dev_pm_domain_attach(dev, true);
-		if (ret)
-			return ret;
+		goto err_disable_clks;
 	}
 
 	provider = &qp->provider;
@@ -514,8 +513,7 @@ int qnoc_probe(struct platform_device *pdev)
 	ret = icc_provider_add(provider);
 	if (ret) {
 		dev_err(dev, "error adding interconnect provider: %d\n", ret);
-		clk_bulk_disable_unprepare(qp->num_clks, qp->bus_clks);
-		return ret;
+		goto err_disable_clks;
 	}
 
 	for (i = 0; i < num_nodes; i++) {
@@ -550,8 +548,9 @@ int qnoc_probe(struct platform_device *pdev)
 	return 0;
 err:
 	icc_nodes_remove(provider);
-	clk_bulk_disable_unprepare(qp->num_clks, qp->bus_clks);
 	icc_provider_del(provider);
+err_disable_clks:
+	clk_bulk_disable_unprepare(qp->num_clks, qp->bus_clks);
 
 	return ret;
 }
-- 
2.39.1

Re: [PATCH 07/23] interconnect: qcom: rpm: fix probe PM domain error handling

[Konrad Dybcio]

On 1.02.2023 11:15, Johan Hovold wrote:
> Make sure to disable clocks also in case attaching the power domain
> fails.
> 
> Fixes: 7de109c0abe9 ("interconnect: icc-rpm: Add support for bus power domain")
> Cc: stable@vger.kernel.org      # 5.17
> Cc: Yassine Oudjana <y.oudjana@protonmail.com>
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>

Konrad
>  drivers/interconnect/qcom/icc-rpm.c | 9 ++++-----
>  1 file changed, 4 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/interconnect/qcom/icc-rpm.c b/drivers/interconnect/qcom/icc-rpm.c
> index 91778cfcbc65..da595059cafd 100644
> --- a/drivers/interconnect/qcom/icc-rpm.c
> +++ b/drivers/interconnect/qcom/icc-rpm.c
> @@ -498,8 +498,7 @@ int qnoc_probe(struct platform_device *pdev)
>  
>  	if (desc->has_bus_pd) {
>  		ret = dev_pm_domain_attach(dev, true);
> -		if (ret)
> -			return ret;
> +		goto err_disable_clks;
>  	}
>  
>  	provider = &qp->provider;
> @@ -514,8 +513,7 @@ int qnoc_probe(struct platform_device *pdev)
>  	ret = icc_provider_add(provider);
>  	if (ret) {
>  		dev_err(dev, "error adding interconnect provider: %d\n", ret);
> -		clk_bulk_disable_unprepare(qp->num_clks, qp->bus_clks);
> -		return ret;
> +		goto err_disable_clks;
>  	}
>  
>  	for (i = 0; i < num_nodes; i++) {
> @@ -550,8 +548,9 @@ int qnoc_probe(struct platform_device *pdev)
>  	return 0;
>  err:
>  	icc_nodes_remove(provider);
> -	clk_bulk_disable_unprepare(qp->num_clks, qp->bus_clks);
>  	icc_provider_del(provider);
> +err_disable_clks:
> +	clk_bulk_disable_unprepare(qp->num_clks, qp->bus_clks);
>  
>  	return ret;
>  }

Re: [PATCH 07/23] interconnect: qcom: rpm: fix probe PM domain error handling

[Christophe JAILLET]

Le 01/02/2023 à 11:15, Johan Hovold a écrit :
> Make sure to disable clocks also in case attaching the power domain
> fails.
> 
> Fixes: 7de109c0abe9 ("interconnect: icc-rpm: Add support for bus power domain")
> Cc: stable-u79uwXL29TY76Z2rM5mHXA@public.gmane.org      # 5.17
> Cc: Yassine Oudjana <y.oudjana-g/b1ySJe57IN+BqQ9rBEUg@public.gmane.org>
> Signed-off-by: Johan Hovold <johan+linaro-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
> ---
>   drivers/interconnect/qcom/icc-rpm.c | 9 ++++-----
>   1 file changed, 4 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/interconnect/qcom/icc-rpm.c b/drivers/interconnect/qcom/icc-rpm.c
> index 91778cfcbc65..da595059cafd 100644
> --- a/drivers/interconnect/qcom/icc-rpm.c
> +++ b/drivers/interconnect/qcom/icc-rpm.c
> @@ -498,8 +498,7 @@ int qnoc_probe(struct platform_device *pdev)
>   
>   	if (desc->has_bus_pd) {
>   		ret = dev_pm_domain_attach(dev, true);
> -		if (ret)
> -			return ret;
> +		goto err_disable_clks;

Hi,
this change looks strange because we now skip the rest of the function.

Is it really intended?


Also, should dev_pm_domain_detach() be called somewhere in the error 
handling path and remove function ?

CJ


>   	}
>   
>   	provider = &qp->provider;
> @@ -514,8 +513,7 @@ int qnoc_probe(struct platform_device *pdev)
>   	ret = icc_provider_add(provider);
>   	if (ret) {
>   		dev_err(dev, "error adding interconnect provider: %d\n", ret);
> -		clk_bulk_disable_unprepare(qp->num_clks, qp->bus_clks);
> -		return ret;
> +		goto err_disable_clks;
>   	}
>   
>   	for (i = 0; i < num_nodes; i++) {
> @@ -550,8 +548,9 @@ int qnoc_probe(struct platform_device *pdev)
>   	return 0;
>   err:
>   	icc_nodes_remove(provider);
> -	clk_bulk_disable_unprepare(qp->num_clks, qp->bus_clks);
>   	icc_provider_del(provider);
> +err_disable_clks:
> +	clk_bulk_disable_unprepare(qp->num_clks, qp->bus_clks);
>   
>   	return ret;
>   }

Re: [PATCH 07/23] interconnect: qcom: rpm: fix probe PM domain error handling

[Johan Hovold]

On Sat, Mar 11, 2023 at 07:17:50PM +0100, Christophe JAILLET wrote:
> Le 01/02/2023 à 11:15, Johan Hovold a écrit :
> > Make sure to disable clocks also in case attaching the power domain
> > fails.
> > 
> > Fixes: 7de109c0abe9 ("interconnect: icc-rpm: Add support for bus power domain")
> > Cc: stable-u79uwXL29TY76Z2rM5mHXA@public.gmane.org      # 5.17
> > Cc: Yassine Oudjana <y.oudjana-g/b1ySJe57IN+BqQ9rBEUg@public.gmane.org>
> > Signed-off-by: Johan Hovold <johan+linaro-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
> > ---
> >   drivers/interconnect/qcom/icc-rpm.c | 9 ++++-----
> >   1 file changed, 4 insertions(+), 5 deletions(-)
> > 
> > diff --git a/drivers/interconnect/qcom/icc-rpm.c b/drivers/interconnect/qcom/icc-rpm.c
> > index 91778cfcbc65..da595059cafd 100644
> > --- a/drivers/interconnect/qcom/icc-rpm.c
> > +++ b/drivers/interconnect/qcom/icc-rpm.c
> > @@ -498,8 +498,7 @@ int qnoc_probe(struct platform_device *pdev)
> >   
> >   	if (desc->has_bus_pd) {
> >   		ret = dev_pm_domain_attach(dev, true);
> > -		if (ret)
> > -			return ret;
> > +		goto err_disable_clks;
> 
> Hi,
> this change looks strange because we now skip the rest of the function.
> 
> Is it really intended?

No, this was definitely not intentional. Thanks for catching this. I'll
send a follow up fix for Georgi to fold in or apply on top.

> Also, should dev_pm_domain_detach() be called somewhere in the error 
> handling path and remove function ?

In principle, yes. (I think read the above as being another device
managed resource.)

It turns out, however, that this code is totally bogus as any power
domain would already have been attached by the platform bus code and the
above call would always just succeed. The platform code would also
handle detach on errors. 

I'll send a patch to remove this.

Johan

[PATCH 08/23] interconnect: qcom: rpm: fix registration race

[Johan Hovold]

The current interconnect provider registration interface is inherently
racy as nodes are not added until the after adding the provider. This
can specifically cause racing DT lookups to fail.

Switch to using the new API where the provider is not registered until
after it has been fully initialised.

Fixes: 62feb14ee8a3 ("interconnect: qcom: Consolidate interconnect RPM support")
Fixes: 30c8fa3ec61a ("interconnect: qcom: Add MSM8916 interconnect provider driver")
Cc: stable@vger.kernel.org	# 5.7
Cc: Jun Nie <jun.nie@linaro.org>
Cc: Georgi Djakov <georgi.djakov@linaro.org>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 drivers/interconnect/qcom/icc-rpm.c | 23 ++++++++++++-----------
 1 file changed, 12 insertions(+), 11 deletions(-)

diff --git a/drivers/interconnect/qcom/icc-rpm.c b/drivers/interconnect/qcom/icc-rpm.c
index da595059cafd..4d0997b210f7 100644
--- a/drivers/interconnect/qcom/icc-rpm.c
+++ b/drivers/interconnect/qcom/icc-rpm.c
@@ -502,7 +502,6 @@ int qnoc_probe(struct platform_device *pdev)
 	}
 
 	provider = &qp->provider;
-	INIT_LIST_HEAD(&provider->nodes);
 	provider->dev = dev;
 	provider->set = qcom_icc_set;
 	provider->pre_aggregate = qcom_icc_pre_bw_aggregate;
@@ -510,11 +509,7 @@ int qnoc_probe(struct platform_device *pdev)
 	provider->xlate_extended = qcom_icc_xlate_extended;
 	provider->data = data;
 
-	ret = icc_provider_add(provider);
-	if (ret) {
-		dev_err(dev, "error adding interconnect provider: %d\n", ret);
-		goto err_disable_clks;
-	}
+	icc_provider_init(provider);
 
 	for (i = 0; i < num_nodes; i++) {
 		size_t j;
@@ -522,7 +517,7 @@ int qnoc_probe(struct platform_device *pdev)
 		node = icc_node_create(qnodes[i]->id);
 		if (IS_ERR(node)) {
 			ret = PTR_ERR(node);
-			goto err;
+			goto err_remove_nodes;
 		}
 
 		node->name = qnodes[i]->name;
@@ -536,19 +531,25 @@ int qnoc_probe(struct platform_device *pdev)
 	}
 	data->num_nodes = num_nodes;
 
+	ret = icc_provider_register(provider);
+	if (ret)
+		goto err_remove_nodes;
+
 	platform_set_drvdata(pdev, qp);
 
 	/* Populate child NoC devices if any */
 	if (of_get_child_count(dev->of_node) > 0) {
 		ret = of_platform_populate(dev->of_node, NULL, NULL, dev);
 		if (ret)
-			goto err;
+			goto err_deregister_provider;
 	}
 
 	return 0;
-err:
+
+err_deregister_provider:
+	icc_provider_deregister(provider);
+err_remove_nodes:
 	icc_nodes_remove(provider);
-	icc_provider_del(provider);
 err_disable_clks:
 	clk_bulk_disable_unprepare(qp->num_clks, qp->bus_clks);
 
@@ -560,9 +561,9 @@ int qnoc_remove(struct platform_device *pdev)
 {
 	struct qcom_icc_provider *qp = platform_get_drvdata(pdev);
 
+	icc_provider_deregister(&qp->provider);
 	icc_nodes_remove(&qp->provider);
 	clk_bulk_disable_unprepare(qp->num_clks, qp->bus_clks);
-	icc_provider_del(&qp->provider);
 
 	return 0;
 }
-- 
2.39.1

Re: [PATCH 08/23] interconnect: qcom: rpm: fix registration race

[Konrad Dybcio]

On 1.02.2023 11:15, Johan Hovold wrote:
> The current interconnect provider registration interface is inherently
> racy as nodes are not added until the after adding the provider. This
> can specifically cause racing DT lookups to fail.
> 
> Switch to using the new API where the provider is not registered until
> after it has been fully initialised.
> 
> Fixes: 62feb14ee8a3 ("interconnect: qcom: Consolidate interconnect RPM support")
> Fixes: 30c8fa3ec61a ("interconnect: qcom: Add MSM8916 interconnect provider driver")
> Cc: stable@vger.kernel.org	# 5.7
> Cc: Jun Nie <jun.nie@linaro.org>
> Cc: Georgi Djakov <georgi.djakov@linaro.org>
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>

Konrad
>  drivers/interconnect/qcom/icc-rpm.c | 23 ++++++++++++-----------
>  1 file changed, 12 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/interconnect/qcom/icc-rpm.c b/drivers/interconnect/qcom/icc-rpm.c
> index da595059cafd..4d0997b210f7 100644
> --- a/drivers/interconnect/qcom/icc-rpm.c
> +++ b/drivers/interconnect/qcom/icc-rpm.c
> @@ -502,7 +502,6 @@ int qnoc_probe(struct platform_device *pdev)
>  	}
>  
>  	provider = &qp->provider;
> -	INIT_LIST_HEAD(&provider->nodes);
>  	provider->dev = dev;
>  	provider->set = qcom_icc_set;
>  	provider->pre_aggregate = qcom_icc_pre_bw_aggregate;
> @@ -510,11 +509,7 @@ int qnoc_probe(struct platform_device *pdev)
>  	provider->xlate_extended = qcom_icc_xlate_extended;
>  	provider->data = data;
>  
> -	ret = icc_provider_add(provider);
> -	if (ret) {
> -		dev_err(dev, "error adding interconnect provider: %d\n", ret);
> -		goto err_disable_clks;
> -	}
> +	icc_provider_init(provider);
>  
>  	for (i = 0; i < num_nodes; i++) {
>  		size_t j;
> @@ -522,7 +517,7 @@ int qnoc_probe(struct platform_device *pdev)
>  		node = icc_node_create(qnodes[i]->id);
>  		if (IS_ERR(node)) {
>  			ret = PTR_ERR(node);
> -			goto err;
> +			goto err_remove_nodes;
>  		}
>  
>  		node->name = qnodes[i]->name;
> @@ -536,19 +531,25 @@ int qnoc_probe(struct platform_device *pdev)
>  	}
>  	data->num_nodes = num_nodes;
>  
> +	ret = icc_provider_register(provider);
> +	if (ret)
> +		goto err_remove_nodes;
> +
>  	platform_set_drvdata(pdev, qp);
>  
>  	/* Populate child NoC devices if any */
>  	if (of_get_child_count(dev->of_node) > 0) {
>  		ret = of_platform_populate(dev->of_node, NULL, NULL, dev);
>  		if (ret)
> -			goto err;
> +			goto err_deregister_provider;
>  	}
>  
>  	return 0;
> -err:
> +
> +err_deregister_provider:
> +	icc_provider_deregister(provider);
> +err_remove_nodes:
>  	icc_nodes_remove(provider);
> -	icc_provider_del(provider);
>  err_disable_clks:
>  	clk_bulk_disable_unprepare(qp->num_clks, qp->bus_clks);
>  
> @@ -560,9 +561,9 @@ int qnoc_remove(struct platform_device *pdev)
>  {
>  	struct qcom_icc_provider *qp = platform_get_drvdata(pdev);
>  
> +	icc_provider_deregister(&qp->provider);
>  	icc_nodes_remove(&qp->provider);
>  	clk_bulk_disable_unprepare(qp->num_clks, qp->bus_clks);
> -	icc_provider_del(&qp->provider);
>  
>  	return 0;
>  }

Re: [PATCH 08/23] interconnect: qcom: rpm: fix registration race

[Jun Nie]

Johan Hovold <johan+linaro@kernel.org> 于2023年2月1日周三 18:16写道：
>
> The current interconnect provider registration interface is inherently
> racy as nodes are not added until the after adding the provider. This
> can specifically cause racing DT lookups to fail.
>
> Switch to using the new API where the provider is not registered until
> after it has been fully initialised.
>
> Fixes: 62feb14ee8a3 ("interconnect: qcom: Consolidate interconnect RPM support")
> Fixes: 30c8fa3ec61a ("interconnect: qcom: Add MSM8916 interconnect provider driver")
> Cc: stable@vger.kernel.org      # 5.7
> Cc: Jun Nie <jun.nie@linaro.org>
> Cc: Georgi Djakov <georgi.djakov@linaro.org>
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---
>  drivers/interconnect/qcom/icc-rpm.c | 23 ++++++++++++-----------
>  1 file changed, 12 insertions(+), 11 deletions(-)
>
Reviewed-by: Jun Nie <jun.nie@linaro.org>

[PATCH 09/23] interconnect: qcom: rpmh: fix probe child-node error handling

[Johan Hovold]

Make sure to clean up and release resources properly also in case probe
fails when populating child devices.

Fixes: 57eb14779dfd ("interconnect: qcom: icc-rpmh: Support child NoC device probe")
Cc: stable@vger.kernel.org      # 6.0
Cc: Luca Weiss <luca.weiss@fairphone.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 drivers/interconnect/qcom/icc-rpmh.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/interconnect/qcom/icc-rpmh.c b/drivers/interconnect/qcom/icc-rpmh.c
index fd17291c61eb..5168bbf3d92f 100644
--- a/drivers/interconnect/qcom/icc-rpmh.c
+++ b/drivers/interconnect/qcom/icc-rpmh.c
@@ -235,8 +235,11 @@ int qcom_icc_rpmh_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, qp);
 
 	/* Populate child NoC devices if any */
-	if (of_get_child_count(dev->of_node) > 0)
-		return of_platform_populate(dev->of_node, NULL, NULL, dev);
+	if (of_get_child_count(dev->of_node) > 0) {
+		ret = of_platform_populate(dev->of_node, NULL, NULL, dev);
+		if (ret)
+			goto err;
+	}
 
 	return 0;
 err:
-- 
2.39.1

Re: [PATCH 09/23] interconnect: qcom: rpmh: fix probe child-node error handling

[Konrad Dybcio]

On 1.02.2023 11:15, Johan Hovold wrote:
> Make sure to clean up and release resources properly also in case probe
> fails when populating child devices.
> 
> Fixes: 57eb14779dfd ("interconnect: qcom: icc-rpmh: Support child NoC device probe")
> Cc: stable@vger.kernel.org      # 6.0
> Cc: Luca Weiss <luca.weiss@fairphone.com>
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>

Konrad
>  drivers/interconnect/qcom/icc-rpmh.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/interconnect/qcom/icc-rpmh.c b/drivers/interconnect/qcom/icc-rpmh.c
> index fd17291c61eb..5168bbf3d92f 100644
> --- a/drivers/interconnect/qcom/icc-rpmh.c
> +++ b/drivers/interconnect/qcom/icc-rpmh.c
> @@ -235,8 +235,11 @@ int qcom_icc_rpmh_probe(struct platform_device *pdev)
>  	platform_set_drvdata(pdev, qp);
>  
>  	/* Populate child NoC devices if any */
> -	if (of_get_child_count(dev->of_node) > 0)
> -		return of_platform_populate(dev->of_node, NULL, NULL, dev);
> +	if (of_get_child_count(dev->of_node) > 0) {
> +		ret = of_platform_populate(dev->of_node, NULL, NULL, dev);
> +		if (ret)
> +			goto err;
> +	}
>  
>  	return 0;
>  err:

[PATCH 10/23] interconnect: qcom: rpmh: fix registration race

[Johan Hovold]

The current interconnect provider registration interface is inherently
racy as nodes are not added until the after adding the provider. This
can specifically cause racing DT lookups to fail.

Switch to using the new API where the provider is not registered until
after it has been fully initialised.

Fixes: 976daac4a1c5 ("interconnect: qcom: Consolidate interconnect RPMh support")
Cc: stable@vger.kernel.org      # 5.7
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 drivers/interconnect/qcom/icc-rpmh.c | 25 +++++++++++++++----------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/drivers/interconnect/qcom/icc-rpmh.c b/drivers/interconnect/qcom/icc-rpmh.c
index 5168bbf3d92f..fdb5e58e408b 100644
--- a/drivers/interconnect/qcom/icc-rpmh.c
+++ b/drivers/interconnect/qcom/icc-rpmh.c
@@ -192,9 +192,10 @@ int qcom_icc_rpmh_probe(struct platform_device *pdev)
 	provider->pre_aggregate = qcom_icc_pre_aggregate;
 	provider->aggregate = qcom_icc_aggregate;
 	provider->xlate_extended = qcom_icc_xlate_extended;
-	INIT_LIST_HEAD(&provider->nodes);
 	provider->data = data;
 
+	icc_provider_init(provider);
+
 	qp->dev = dev;
 	qp->bcms = desc->bcms;
 	qp->num_bcms = desc->num_bcms;
@@ -203,10 +204,6 @@ int qcom_icc_rpmh_probe(struct platform_device *pdev)
 	if (IS_ERR(qp->voter))
 		return PTR_ERR(qp->voter);
 
-	ret = icc_provider_add(provider);
-	if (ret)
-		return ret;
-
 	for (i = 0; i < qp->num_bcms; i++)
 		qcom_icc_bcm_init(qp->bcms[i], dev);
 
@@ -218,7 +215,7 @@ int qcom_icc_rpmh_probe(struct platform_device *pdev)
 		node = icc_node_create(qn->id);
 		if (IS_ERR(node)) {
 			ret = PTR_ERR(node);
-			goto err;
+			goto err_remove_nodes;
 		}
 
 		node->name = qn->name;
@@ -232,19 +229,27 @@ int qcom_icc_rpmh_probe(struct platform_device *pdev)
 	}
 
 	data->num_nodes = num_nodes;
+
+	ret = icc_provider_register(provider);
+	if (ret)
+		goto err_remove_nodes;
+
 	platform_set_drvdata(pdev, qp);
 
 	/* Populate child NoC devices if any */
 	if (of_get_child_count(dev->of_node) > 0) {
 		ret = of_platform_populate(dev->of_node, NULL, NULL, dev);
 		if (ret)
-			goto err;
+			goto err_deregister_provider;
 	}
 
 	return 0;
-err:
+
+err_deregister_provider:
+	icc_provider_deregister(provider);
+err_remove_nodes:
 	icc_nodes_remove(provider);
-	icc_provider_del(provider);
+
 	return ret;
 }
 EXPORT_SYMBOL_GPL(qcom_icc_rpmh_probe);
@@ -253,8 +258,8 @@ int qcom_icc_rpmh_remove(struct platform_device *pdev)
 {
 	struct qcom_icc_provider *qp = platform_get_drvdata(pdev);
 
+	icc_provider_deregister(&qp->provider);
 	icc_nodes_remove(&qp->provider);
-	icc_provider_del(&qp->provider);
 
 	return 0;
 }
-- 
2.39.1

Re: [PATCH 10/23] interconnect: qcom: rpmh: fix registration race

[Konrad Dybcio]

On 1.02.2023 11:15, Johan Hovold wrote:
> The current interconnect provider registration interface is inherently
> racy as nodes are not added until the after adding the provider. This
> can specifically cause racing DT lookups to fail.
> 
> Switch to using the new API where the provider is not registered until
> after it has been fully initialised.
> 
> Fixes: 976daac4a1c5 ("interconnect: qcom: Consolidate interconnect RPMh support")
> Cc: stable@vger.kernel.org      # 5.7
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>

Konrad
>  drivers/interconnect/qcom/icc-rpmh.c | 25 +++++++++++++++----------
>  1 file changed, 15 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/interconnect/qcom/icc-rpmh.c b/drivers/interconnect/qcom/icc-rpmh.c
> index 5168bbf3d92f..fdb5e58e408b 100644
> --- a/drivers/interconnect/qcom/icc-rpmh.c
> +++ b/drivers/interconnect/qcom/icc-rpmh.c
> @@ -192,9 +192,10 @@ int qcom_icc_rpmh_probe(struct platform_device *pdev)
>  	provider->pre_aggregate = qcom_icc_pre_aggregate;
>  	provider->aggregate = qcom_icc_aggregate;
>  	provider->xlate_extended = qcom_icc_xlate_extended;
> -	INIT_LIST_HEAD(&provider->nodes);
>  	provider->data = data;
>  
> +	icc_provider_init(provider);
> +
>  	qp->dev = dev;
>  	qp->bcms = desc->bcms;
>  	qp->num_bcms = desc->num_bcms;
> @@ -203,10 +204,6 @@ int qcom_icc_rpmh_probe(struct platform_device *pdev)
>  	if (IS_ERR(qp->voter))
>  		return PTR_ERR(qp->voter);
>  
> -	ret = icc_provider_add(provider);
> -	if (ret)
> -		return ret;
> -
>  	for (i = 0; i < qp->num_bcms; i++)
>  		qcom_icc_bcm_init(qp->bcms[i], dev);
>  
> @@ -218,7 +215,7 @@ int qcom_icc_rpmh_probe(struct platform_device *pdev)
>  		node = icc_node_create(qn->id);
>  		if (IS_ERR(node)) {
>  			ret = PTR_ERR(node);
> -			goto err;
> +			goto err_remove_nodes;
>  		}
>  
>  		node->name = qn->name;
> @@ -232,19 +229,27 @@ int qcom_icc_rpmh_probe(struct platform_device *pdev)
>  	}
>  
>  	data->num_nodes = num_nodes;
> +
> +	ret = icc_provider_register(provider);
> +	if (ret)
> +		goto err_remove_nodes;
> +
>  	platform_set_drvdata(pdev, qp);
>  
>  	/* Populate child NoC devices if any */
>  	if (of_get_child_count(dev->of_node) > 0) {
>  		ret = of_platform_populate(dev->of_node, NULL, NULL, dev);
>  		if (ret)
> -			goto err;
> +			goto err_deregister_provider;
>  	}
>  
>  	return 0;
> -err:
> +
> +err_deregister_provider:
> +	icc_provider_deregister(provider);
> +err_remove_nodes:
>  	icc_nodes_remove(provider);
> -	icc_provider_del(provider);
> +
>  	return ret;
>  }
>  EXPORT_SYMBOL_GPL(qcom_icc_rpmh_probe);
> @@ -253,8 +258,8 @@ int qcom_icc_rpmh_remove(struct platform_device *pdev)
>  {
>  	struct qcom_icc_provider *qp = platform_get_drvdata(pdev);
>  
> +	icc_provider_deregister(&qp->provider);
>  	icc_nodes_remove(&qp->provider);
> -	icc_provider_del(&qp->provider);
>  
>  	return 0;
>  }

[PATCH 11/23] interconnect: qcom: msm8974: fix registration race

[Johan Hovold]

The current interconnect provider registration interface is inherently
racy as nodes are not added until the after adding the provider. This
can specifically cause racing DT lookups to fail.

Switch to using the new API where the provider is not registered until
after it has been fully initialised.

Fixes: 4e60a9568dc6 ("interconnect: qcom: add msm8974 driver")
Cc: stable@vger.kernel.org      # 5.5
Cc: Brian Masney <bmasney@redhat.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 drivers/interconnect/qcom/msm8974.c | 20 ++++++++------------
 1 file changed, 8 insertions(+), 12 deletions(-)

diff --git a/drivers/interconnect/qcom/msm8974.c b/drivers/interconnect/qcom/msm8974.c
index 5ea192f1141d..1828deaca443 100644
--- a/drivers/interconnect/qcom/msm8974.c
+++ b/drivers/interconnect/qcom/msm8974.c
@@ -692,7 +692,6 @@ static int msm8974_icc_probe(struct platform_device *pdev)
 		return ret;
 
 	provider = &qp->provider;
-	INIT_LIST_HEAD(&provider->nodes);
 	provider->dev = dev;
 	provider->set = msm8974_icc_set;
 	provider->aggregate = icc_std_aggregate;
@@ -700,11 +699,7 @@ static int msm8974_icc_probe(struct platform_device *pdev)
 	provider->data = data;
 	provider->get_bw = msm8974_get_bw;
 
-	ret = icc_provider_add(provider);
-	if (ret) {
-		dev_err(dev, "error adding interconnect provider: %d\n", ret);
-		goto err_disable_clks;
-	}
+	icc_provider_init(provider);
 
 	for (i = 0; i < num_nodes; i++) {
 		size_t j;
@@ -712,7 +707,7 @@ static int msm8974_icc_probe(struct platform_device *pdev)
 		node = icc_node_create(qnodes[i]->id);
 		if (IS_ERR(node)) {
 			ret = PTR_ERR(node);
-			goto err_del_icc;
+			goto err_remove_nodes;
 		}
 
 		node->name = qnodes[i]->name;
@@ -729,15 +724,16 @@ static int msm8974_icc_probe(struct platform_device *pdev)
 	}
 	data->num_nodes = num_nodes;
 
+	ret = icc_provider_register(provider);
+	if (ret)
+		goto err_remove_nodes;
+
 	platform_set_drvdata(pdev, qp);
 
 	return 0;
 
-err_del_icc:
+err_remove_nodes:
 	icc_nodes_remove(provider);
-	icc_provider_del(provider);
-
-err_disable_clks:
 	clk_bulk_disable_unprepare(qp->num_clks, qp->bus_clks);
 
 	return ret;
@@ -747,9 +743,9 @@ static int msm8974_icc_remove(struct platform_device *pdev)
 {
 	struct msm8974_icc_provider *qp = platform_get_drvdata(pdev);
 
+	icc_provider_deregister(&qp->provider);
 	icc_nodes_remove(&qp->provider);
 	clk_bulk_disable_unprepare(qp->num_clks, qp->bus_clks);
-	icc_provider_del(&qp->provider);
 
 	return 0;
 }
-- 
2.39.1

Re: [PATCH 11/23] interconnect: qcom: msm8974: fix registration race

[Brian Masney]

On Wed, Feb 01, 2023 at 11:15:47AM +0100, Johan Hovold wrote:
> The current interconnect provider registration interface is inherently
> racy as nodes are not added until the after adding the provider. This
> can specifically cause racing DT lookups to fail.
> 
> Switch to using the new API where the provider is not registered until
> after it has been fully initialised.
> 
> Fixes: 4e60a9568dc6 ("interconnect: qcom: add msm8974 driver")
> Cc: stable@vger.kernel.org      # 5.5
> Cc: Brian Masney <bmasney@redhat.com>
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>

Reviewed-by: Brian Masney <bmasney@redhat.com>

Re: [PATCH 11/23] interconnect: qcom: msm8974: fix registration race

[Konrad Dybcio]

On 1.02.2023 11:15, Johan Hovold wrote:
> The current interconnect provider registration interface is inherently
> racy as nodes are not added until the after adding the provider. This
> can specifically cause racing DT lookups to fail.
> 
> Switch to using the new API where the provider is not registered until
> after it has been fully initialised.
> 
> Fixes: 4e60a9568dc6 ("interconnect: qcom: add msm8974 driver")
> Cc: stable@vger.kernel.org      # 5.5
> Cc: Brian Masney <bmasney@redhat.com>
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>

Konrad
>  drivers/interconnect/qcom/msm8974.c | 20 ++++++++------------
>  1 file changed, 8 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/interconnect/qcom/msm8974.c b/drivers/interconnect/qcom/msm8974.c
> index 5ea192f1141d..1828deaca443 100644
> --- a/drivers/interconnect/qcom/msm8974.c
> +++ b/drivers/interconnect/qcom/msm8974.c
> @@ -692,7 +692,6 @@ static int msm8974_icc_probe(struct platform_device *pdev)
>  		return ret;
>  
>  	provider = &qp->provider;
> -	INIT_LIST_HEAD(&provider->nodes);
>  	provider->dev = dev;
>  	provider->set = msm8974_icc_set;
>  	provider->aggregate = icc_std_aggregate;
> @@ -700,11 +699,7 @@ static int msm8974_icc_probe(struct platform_device *pdev)
>  	provider->data = data;
>  	provider->get_bw = msm8974_get_bw;
>  
> -	ret = icc_provider_add(provider);
> -	if (ret) {
> -		dev_err(dev, "error adding interconnect provider: %d\n", ret);
> -		goto err_disable_clks;
> -	}
> +	icc_provider_init(provider);
>  
>  	for (i = 0; i < num_nodes; i++) {
>  		size_t j;
> @@ -712,7 +707,7 @@ static int msm8974_icc_probe(struct platform_device *pdev)
>  		node = icc_node_create(qnodes[i]->id);
>  		if (IS_ERR(node)) {
>  			ret = PTR_ERR(node);
> -			goto err_del_icc;
> +			goto err_remove_nodes;
>  		}
>  
>  		node->name = qnodes[i]->name;
> @@ -729,15 +724,16 @@ static int msm8974_icc_probe(struct platform_device *pdev)
>  	}
>  	data->num_nodes = num_nodes;
>  
> +	ret = icc_provider_register(provider);
> +	if (ret)
> +		goto err_remove_nodes;
> +
>  	platform_set_drvdata(pdev, qp);
>  
>  	return 0;
>  
> -err_del_icc:
> +err_remove_nodes:
>  	icc_nodes_remove(provider);
> -	icc_provider_del(provider);
> -
> -err_disable_clks:
>  	clk_bulk_disable_unprepare(qp->num_clks, qp->bus_clks);
>  
>  	return ret;
> @@ -747,9 +743,9 @@ static int msm8974_icc_remove(struct platform_device *pdev)
>  {
>  	struct msm8974_icc_provider *qp = platform_get_drvdata(pdev);
>  
> +	icc_provider_deregister(&qp->provider);
>  	icc_nodes_remove(&qp->provider);
>  	clk_bulk_disable_unprepare(qp->num_clks, qp->bus_clks);
> -	icc_provider_del(&qp->provider);
>  
>  	return 0;
>  }

[PATCH 12/23] interconnect: qcom: sm8450: fix registration race

[Johan Hovold]

The current interconnect provider registration interface is inherently
racy as nodes are not added until the after adding the provider. This
can specifically cause racing DT lookups to fail.

Switch to using the new API where the provider is not registered until
after it has been fully initialised.

Fixes: fafc114a468e ("interconnect: qcom: Add SM8450 interconnect provider driver")
Cc: stable@vger.kernel.org      # 5.17
Cc: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 drivers/interconnect/qcom/sm8450.c | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/drivers/interconnect/qcom/sm8450.c b/drivers/interconnect/qcom/sm8450.c
index e3a12e3d6e06..c7a8bbf102a3 100644
--- a/drivers/interconnect/qcom/sm8450.c
+++ b/drivers/interconnect/qcom/sm8450.c
@@ -1876,9 +1876,10 @@ static int qnoc_probe(struct platform_device *pdev)
 	provider->pre_aggregate = qcom_icc_pre_aggregate;
 	provider->aggregate = qcom_icc_aggregate;
 	provider->xlate_extended = qcom_icc_xlate_extended;
-	INIT_LIST_HEAD(&provider->nodes);
 	provider->data = data;
 
+	icc_provider_init(provider);
+
 	qp->dev = &pdev->dev;
 	qp->bcms = desc->bcms;
 	qp->num_bcms = desc->num_bcms;
@@ -1887,12 +1888,6 @@ static int qnoc_probe(struct platform_device *pdev)
 	if (IS_ERR(qp->voter))
 		return PTR_ERR(qp->voter);
 
-	ret = icc_provider_add(provider);
-	if (ret) {
-		dev_err(&pdev->dev, "error adding interconnect provider\n");
-		return ret;
-	}
-
 	for (i = 0; i < qp->num_bcms; i++)
 		qcom_icc_bcm_init(qp->bcms[i], &pdev->dev);
 
@@ -1905,7 +1900,7 @@ static int qnoc_probe(struct platform_device *pdev)
 		node = icc_node_create(qnodes[i]->id);
 		if (IS_ERR(node)) {
 			ret = PTR_ERR(node);
-			goto err;
+			goto err_remove_nodes;
 		}
 
 		node->name = qnodes[i]->name;
@@ -1919,12 +1914,17 @@ static int qnoc_probe(struct platform_device *pdev)
 	}
 	data->num_nodes = num_nodes;
 
+	ret = icc_provider_register(provider);
+	if (ret)
+		goto err_remove_nodes;
+
 	platform_set_drvdata(pdev, qp);
 
 	return 0;
-err:
+
+err_remove_nodes:
 	icc_nodes_remove(provider);
-	icc_provider_del(provider);
+
 	return ret;
 }
 
@@ -1932,8 +1932,8 @@ static int qnoc_remove(struct platform_device *pdev)
 {
 	struct qcom_icc_provider *qp = platform_get_drvdata(pdev);
 
+	icc_provider_deregister(&qp->provider);
 	icc_nodes_remove(&qp->provider);
-	icc_provider_del(&qp->provider);
 
 	return 0;
 }
-- 
2.39.1

Re: [PATCH 12/23] interconnect: qcom: sm8450: fix registration race

[Konrad Dybcio]

On 1.02.2023 11:15, Johan Hovold wrote:
> The current interconnect provider registration interface is inherently
> racy as nodes are not added until the after adding the provider. This
> can specifically cause racing DT lookups to fail.
> 
> Switch to using the new API where the provider is not registered until
> after it has been fully initialised.
> 
> Fixes: fafc114a468e ("interconnect: qcom: Add SM8450 interconnect provider driver")
> Cc: stable@vger.kernel.org      # 5.17
> Cc: Vinod Koul <vkoul@kernel.org>
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>

Konrad
>  drivers/interconnect/qcom/sm8450.c | 22 +++++++++++-----------
>  1 file changed, 11 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/interconnect/qcom/sm8450.c b/drivers/interconnect/qcom/sm8450.c
> index e3a12e3d6e06..c7a8bbf102a3 100644
> --- a/drivers/interconnect/qcom/sm8450.c
> +++ b/drivers/interconnect/qcom/sm8450.c
> @@ -1876,9 +1876,10 @@ static int qnoc_probe(struct platform_device *pdev)
>  	provider->pre_aggregate = qcom_icc_pre_aggregate;
>  	provider->aggregate = qcom_icc_aggregate;
>  	provider->xlate_extended = qcom_icc_xlate_extended;
> -	INIT_LIST_HEAD(&provider->nodes);
>  	provider->data = data;
>  
> +	icc_provider_init(provider);
> +
>  	qp->dev = &pdev->dev;
>  	qp->bcms = desc->bcms;
>  	qp->num_bcms = desc->num_bcms;
> @@ -1887,12 +1888,6 @@ static int qnoc_probe(struct platform_device *pdev)
>  	if (IS_ERR(qp->voter))
>  		return PTR_ERR(qp->voter);
>  
> -	ret = icc_provider_add(provider);
> -	if (ret) {
> -		dev_err(&pdev->dev, "error adding interconnect provider\n");
> -		return ret;
> -	}
> -
>  	for (i = 0; i < qp->num_bcms; i++)
>  		qcom_icc_bcm_init(qp->bcms[i], &pdev->dev);
>  
> @@ -1905,7 +1900,7 @@ static int qnoc_probe(struct platform_device *pdev)
>  		node = icc_node_create(qnodes[i]->id);
>  		if (IS_ERR(node)) {
>  			ret = PTR_ERR(node);
> -			goto err;
> +			goto err_remove_nodes;
>  		}
>  
>  		node->name = qnodes[i]->name;
> @@ -1919,12 +1914,17 @@ static int qnoc_probe(struct platform_device *pdev)
>  	}
>  	data->num_nodes = num_nodes;
>  
> +	ret = icc_provider_register(provider);
> +	if (ret)
> +		goto err_remove_nodes;
> +
>  	platform_set_drvdata(pdev, qp);
>  
>  	return 0;
> -err:
> +
> +err_remove_nodes:
>  	icc_nodes_remove(provider);
> -	icc_provider_del(provider);
> +
>  	return ret;
>  }
>  
> @@ -1932,8 +1932,8 @@ static int qnoc_remove(struct platform_device *pdev)
>  {
>  	struct qcom_icc_provider *qp = platform_get_drvdata(pdev);
>  
> +	icc_provider_deregister(&qp->provider);
>  	icc_nodes_remove(&qp->provider);
> -	icc_provider_del(&qp->provider);
>  
>  	return 0;
>  }

Re: [PATCH 12/23] interconnect: qcom: sm8450: fix registration race

[Vinod Koul]

On 01-02-23, 11:15, Johan Hovold wrote:
> The current interconnect provider registration interface is inherently
> racy as nodes are not added until the after adding the provider. This
> can specifically cause racing DT lookups to fail.
> 
> Switch to using the new API where the provider is not registered until
> after it has been fully initialised.

Reviewed-by: Vinod Koul <vkoul@kernel.org>

-- 
~Vinod

[PATCH 14/23] interconnect: exynos: fix node leak in probe PM QoS error path

[Johan Hovold]

Make sure to add the newly allocated interconnect node to the provider
before adding the PM QoS request so that the node is freed on errors.

Fixes: 2f95b9d5cf0b ("interconnect: Add generic interconnect driver for Exynos SoCs")
Cc: stable@vger.kernel.org      # 5.11
Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 drivers/interconnect/samsung/exynos.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/interconnect/samsung/exynos.c b/drivers/interconnect/samsung/exynos.c
index 6559d8cf8068..e70665899482 100644
--- a/drivers/interconnect/samsung/exynos.c
+++ b/drivers/interconnect/samsung/exynos.c
@@ -149,6 +149,9 @@ static int exynos_generic_icc_probe(struct platform_device *pdev)
 				 &priv->bus_clk_ratio))
 		priv->bus_clk_ratio = EXYNOS_ICC_DEFAULT_BUS_CLK_RATIO;
 
+	icc_node->data = priv;
+	icc_node_add(icc_node, provider);
+
 	/*
 	 * Register a PM QoS request for the parent (devfreq) device.
 	 */
@@ -157,9 +160,6 @@ static int exynos_generic_icc_probe(struct platform_device *pdev)
 	if (ret < 0)
 		goto err_node_del;
 
-	icc_node->data = priv;
-	icc_node_add(icc_node, provider);
-
 	icc_parent_node = exynos_icc_get_parent(bus_dev->of_node);
 	if (IS_ERR(icc_parent_node)) {
 		ret = PTR_ERR(icc_parent_node);
-- 
2.39.1

Re: [PATCH 14/23] interconnect: exynos: fix node leak in probe PM QoS error path

[Krzysztof Kozlowski]

On 01/02/2023 11:15, Johan Hovold wrote:
> Make sure to add the newly allocated interconnect node to the provider
> before adding the PM QoS request so that the node is freed on errors.
> 
> Fixes: 2f95b9d5cf0b ("interconnect: Add generic interconnect driver for Exynos SoCs")
> Cc: stable@vger.kernel.org      # 5.11
> Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---
>  drivers/interconnect/samsung/exynos.c | 6 +++---


Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Best regards,
Krzysztof

[PATCH 15/23] interconnect: exynos: fix registration race

[Johan Hovold]

The current interconnect provider registration interface is inherently
racy as nodes are not added until the after adding the provider. This
can specifically cause racing DT lookups to trigger a NULL-pointer
deference when either a NULL pointer or not fully initialised node is
returned from exynos_generic_icc_xlate().

Switch to using the new API where the provider is not registered until
after it has been fully initialised.

Fixes: 2f95b9d5cf0b ("interconnect: Add generic interconnect driver for Exynos SoCs")
Cc: stable@vger.kernel.org      # 5.11
Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 drivers/interconnect/samsung/exynos.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/interconnect/samsung/exynos.c b/drivers/interconnect/samsung/exynos.c
index e70665899482..72e42603823b 100644
--- a/drivers/interconnect/samsung/exynos.c
+++ b/drivers/interconnect/samsung/exynos.c
@@ -98,12 +98,13 @@ static int exynos_generic_icc_remove(struct platform_device *pdev)
 	struct exynos_icc_priv *priv = platform_get_drvdata(pdev);
 	struct icc_node *parent_node, *node = priv->node;
 
+	icc_provider_deregister(&priv->provider);
+
 	parent_node = exynos_icc_get_parent(priv->dev->parent->of_node);
 	if (parent_node && !IS_ERR(parent_node))
 		icc_link_destroy(node, parent_node);
 
 	icc_nodes_remove(&priv->provider);
-	icc_provider_del(&priv->provider);
 
 	return 0;
 }
@@ -132,15 +133,11 @@ static int exynos_generic_icc_probe(struct platform_device *pdev)
 	provider->inter_set = true;
 	provider->data = priv;
 
-	ret = icc_provider_add(provider);
-	if (ret < 0)
-		return ret;
+	icc_provider_init(provider);
 
 	icc_node = icc_node_create(pdev->id);
-	if (IS_ERR(icc_node)) {
-		ret = PTR_ERR(icc_node);
-		goto err_prov_del;
-	}
+	if (IS_ERR(icc_node))
+		return PTR_ERR(icc_node);
 
 	priv->node = icc_node;
 	icc_node->name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "%pOFn",
@@ -171,14 +168,17 @@ static int exynos_generic_icc_probe(struct platform_device *pdev)
 			goto err_pmqos_del;
 	}
 
+	ret = icc_provider_register(provider);
+	if (ret < 0)
+		goto err_pmqos_del;
+
 	return 0;
 
 err_pmqos_del:
 	dev_pm_qos_remove_request(&priv->qos_req);
 err_node_del:
 	icc_nodes_remove(provider);
-err_prov_del:
-	icc_provider_del(provider);
+
 	return ret;
 }
 
-- 
2.39.1

Re: [PATCH 15/23] interconnect: exynos: fix registration race

[Krzysztof Kozlowski]

On 01/02/2023 11:15, Johan Hovold wrote:
> The current interconnect provider registration interface is inherently
> racy as nodes are not added until the after adding the provider. This
> can specifically cause racing DT lookups to trigger a NULL-pointer
> deference when either a NULL pointer or not fully initialised node is
> returned from exynos_generic_icc_xlate().
> 
> Switch to using the new API where the provider is not registered until
> after it has been fully initialised.
> 
> Fixes: 2f95b9d5cf0b ("interconnect: Add generic interconnect driver for Exynos SoCs")
> Cc: stable@vger.kernel.org      # 5.11
> Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---
>  drivers/interconnect/samsung/exynos.c | 20 ++++++++++----------
>  1 file changed, 10 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/interconnect/samsung/exynos.c b/drivers/interconnect/samsung/exynos.c
> index e70665899482..72e42603823b 100644
> --- a/drivers/interconnect/samsung/exynos.c
> +++ b/drivers/interconnect/samsung/exynos.c
> @@ -98,12 +98,13 @@ static int exynos_generic_icc_remove(struct platform_device *pdev)
>  	struct exynos_icc_priv *priv = platform_get_drvdata(pdev);
>  	struct icc_node *parent_node, *node = priv->node;
>  
> +	icc_provider_deregister(&priv->provider);
> +
>  	parent_node = exynos_icc_get_parent(priv->dev->parent->of_node);
>  	if (parent_node && !IS_ERR(parent_node))
>  		icc_link_destroy(node, parent_node);
>  
>  	icc_nodes_remove(&priv->provider);
> -	icc_provider_del(&priv->provider);
>  
>  	return 0;
>  }
> @@ -132,15 +133,11 @@ static int exynos_generic_icc_probe(struct platform_device *pdev)
>  	provider->inter_set = true;
>  	provider->data = priv;
>  
> -	ret = icc_provider_add(provider);
> -	if (ret < 0)
> -		return ret;
> +	icc_provider_init(provider);
>  
>  	icc_node = icc_node_create(pdev->id);
> -	if (IS_ERR(icc_node)) {
> -		ret = PTR_ERR(icc_node);
> -		goto err_prov_del;
> -	}
> +	if (IS_ERR(icc_node))
> +		return PTR_ERR(icc_node);
>  
>  	priv->node = icc_node;
>  	icc_node->name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "%pOFn",
> @@ -171,14 +168,17 @@ static int exynos_generic_icc_probe(struct platform_device *pdev)
>  			goto err_pmqos_del;
>  	}
>  
> +	ret = icc_provider_register(provider);
> +	if (ret < 0)
> +		goto err_pmqos_del;

If I understand correctly there is no need for icc_link_destroy() in
error path here, right? Even in case of probe retry (defer or whatever
reason) - the link will be removed with icc_nodes_remove()?

Best regards,
Krzysztof

Re: [PATCH 15/23] interconnect: exynos: fix registration race

[Johan Hovold]

On Thu, Feb 02, 2023 at 12:04:49PM +0100, Krzysztof Kozlowski wrote:
> On 01/02/2023 11:15, Johan Hovold wrote:

> > @@ -98,12 +98,13 @@ static int exynos_generic_icc_remove(struct platform_device *pdev)
> >  	struct exynos_icc_priv *priv = platform_get_drvdata(pdev);
> >  	struct icc_node *parent_node, *node = priv->node;
> >  
> > +	icc_provider_deregister(&priv->provider);
> > +
> >  	parent_node = exynos_icc_get_parent(priv->dev->parent->of_node);
> >  	if (parent_node && !IS_ERR(parent_node))
> >  		icc_link_destroy(node, parent_node);
> >  
> >  	icc_nodes_remove(&priv->provider);
> > -	icc_provider_del(&priv->provider);
> >  
> >  	return 0;
> >  }
> > @@ -132,15 +133,11 @@ static int exynos_generic_icc_probe(struct platform_device *pdev)
> >  	provider->inter_set = true;
> >  	provider->data = priv;
> >  
> > -	ret = icc_provider_add(provider);
> > -	if (ret < 0)
> > -		return ret;
> > +	icc_provider_init(provider);
> >  
> >  	icc_node = icc_node_create(pdev->id);
> > -	if (IS_ERR(icc_node)) {
> > -		ret = PTR_ERR(icc_node);
> > -		goto err_prov_del;
> > -	}
> > +	if (IS_ERR(icc_node))
> > +		return PTR_ERR(icc_node);
> >  
> >  	priv->node = icc_node;
> >  	icc_node->name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "%pOFn",
> > @@ -171,14 +168,17 @@ static int exynos_generic_icc_probe(struct platform_device *pdev)
> >  			goto err_pmqos_del;
> >  	}
> >  
> > +	ret = icc_provider_register(provider);
> > +	if (ret < 0)
> > +		goto err_pmqos_del;
> 
> If I understand correctly there is no need for icc_link_destroy() in
> error path here, right? Even in case of probe retry (defer or whatever
> reason) - the link will be removed with icc_nodes_remove()?

Correct, it is no longer needed after the first patch in this series.

The exynos driver was the only driver that bothered to remove links
explicitly, all the others expected the interconnect framework to do so
when destroying nodes even if that was not case until now.

Johan

Re: [PATCH 15/23] interconnect: exynos: fix registration race

[Krzysztof Kozlowski]

On 02/02/2023 13:17, Johan Hovold wrote:
> On Thu, Feb 02, 2023 at 12:04:49PM +0100, Krzysztof Kozlowski wrote:
>> On 01/02/2023 11:15, Johan Hovold wrote:
> 


Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Best regards,
Krzysztof

[PATCH 17/23] memory: tegra: fix interconnect registration race

[Johan Hovold]

The current interconnect provider registration interface is inherently
racy as nodes are not added until the after adding the provider. This
can specifically cause racing DT lookups to fail.

Switch to using the new API where the provider is not registered until
after it has been fully initialised.

Fixes: 06f079816d4c ("memory: tegra-mc: Add interconnect framework")
Cc: stable@vger.kernel.org      # 5.11
Cc: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 drivers/memory/tegra/mc.c | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/drivers/memory/tegra/mc.c b/drivers/memory/tegra/mc.c
index 592907546ee6..5cd28619ea9f 100644
--- a/drivers/memory/tegra/mc.c
+++ b/drivers/memory/tegra/mc.c
@@ -794,16 +794,12 @@ static int tegra_mc_interconnect_setup(struct tegra_mc *mc)
 	mc->provider.aggregate = mc->soc->icc_ops->aggregate;
 	mc->provider.xlate_extended = mc->soc->icc_ops->xlate_extended;
 
-	err = icc_provider_add(&mc->provider);
-	if (err)
-		return err;
+	icc_provider_init(&mc->provider);
 
 	/* create Memory Controller node */
 	node = icc_node_create(TEGRA_ICC_MC);
-	if (IS_ERR(node)) {
-		err = PTR_ERR(node);
-		goto del_provider;
-	}
+	if (IS_ERR(node))
+		return PTR_ERR(node);
 
 	node->name = "Memory Controller";
 	icc_node_add(node, &mc->provider);
@@ -830,12 +826,14 @@ static int tegra_mc_interconnect_setup(struct tegra_mc *mc)
 			goto remove_nodes;
 	}
 
+	err = icc_provider_register(&mc->provider);
+	if (err)
+		goto remove_nodes;
+
 	return 0;
 
 remove_nodes:
 	icc_nodes_remove(&mc->provider);
-del_provider:
-	icc_provider_del(&mc->provider);
 
 	return err;
 }
-- 
2.39.1

Re: [PATCH 17/23] memory: tegra: fix interconnect registration race

[Krzysztof Kozlowski]

On 01/02/2023 11:15, Johan Hovold wrote:
> The current interconnect provider registration interface is inherently
> racy as nodes are not added until the after adding the provider. This
> can specifically cause racing DT lookups to fail.
> 
> Switch to using the new API where the provider is not registered until
> after it has been fully initialised.
> 
> Fixes: 06f079816d4c ("memory: tegra-mc: Add interconnect framework")
> Cc: stable@vger.kernel.org      # 5.11
> Cc: Dmitry Osipenko <digetx@gmail.com>
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>


Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

(or tell me if I should take it via memory-controllers)

Best regards,
Krzysztof

[PATCH 18/23] memory: tegra124-emc: fix interconnect registration race

[Johan Hovold]

The current interconnect provider registration interface is inherently
racy as nodes are not added until the after adding the provider. This
can specifically cause racing DT lookups to fail.

Switch to using the new API where the provider is not registered until
after it has been fully initialised.

Fixes: 380def2d4cf2 ("memory: tegra124: Support interconnect framework")
Cc: stable@vger.kernel.org      # 5.12
Cc: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 drivers/memory/tegra/tegra124-emc.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/memory/tegra/tegra124-emc.c b/drivers/memory/tegra/tegra124-emc.c
index 85bc936c02f9..00ed2b6a0d1b 100644
--- a/drivers/memory/tegra/tegra124-emc.c
+++ b/drivers/memory/tegra/tegra124-emc.c
@@ -1351,15 +1351,13 @@ static int tegra_emc_interconnect_init(struct tegra_emc *emc)
 	emc->provider.aggregate = soc->icc_ops->aggregate;
 	emc->provider.xlate_extended = emc_of_icc_xlate_extended;
 
-	err = icc_provider_add(&emc->provider);
-	if (err)
-		goto err_msg;
+	icc_provider_init(&emc->provider);
 
 	/* create External Memory Controller node */
 	node = icc_node_create(TEGRA_ICC_EMC);
 	if (IS_ERR(node)) {
 		err = PTR_ERR(node);
-		goto del_provider;
+		goto err_msg;
 	}
 
 	node->name = "External Memory Controller";
@@ -1380,12 +1378,14 @@ static int tegra_emc_interconnect_init(struct tegra_emc *emc)
 	node->name = "External Memory (DRAM)";
 	icc_node_add(node, &emc->provider);
 
+	err = icc_provider_register(&emc->provider);
+	if (err)
+		goto remove_nodes;
+
 	return 0;
 
 remove_nodes:
 	icc_nodes_remove(&emc->provider);
-del_provider:
-	icc_provider_del(&emc->provider);
 err_msg:
 	dev_err(emc->dev, "failed to initialize ICC: %d\n", err);
 
-- 
2.39.1

Re: [PATCH 18/23] memory: tegra124-emc: fix interconnect registration race

[Krzysztof Kozlowski]

On 01/02/2023 11:15, Johan Hovold wrote:
> The current interconnect provider registration interface is inherently
> racy as nodes are not added until the after adding the provider. This
> can specifically cause racing DT lookups to fail.
> 
> Switch to using the new API where the provider is not registered until
> after it has been fully initialised.
> 
> Fixes: 380def2d4cf2 ("memory: tegra124: Support interconnect framework")
> Cc: stable@vger.kernel.org      # 5.12
> Cc: Dmitry Osipenko <digetx@gmail.com>
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---


Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Best regards,
Krzysztof

[PATCH 19/23] memory: tegra20-emc: fix interconnect registration race

[Johan Hovold]

The current interconnect provider registration interface is inherently
racy as nodes are not added until the after adding the provider. This
can specifically cause racing DT lookups to fail.

Switch to using the new API where the provider is not registered until
after it has been fully initialised.

Fixes: d5ef16ba5fbe ("memory: tegra20: Support interconnect framework")
Cc: stable@vger.kernel.org      # 5.11
Cc: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 drivers/memory/tegra/tegra20-emc.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/memory/tegra/tegra20-emc.c b/drivers/memory/tegra/tegra20-emc.c
index bd4e37b6552d..fd595c851a27 100644
--- a/drivers/memory/tegra/tegra20-emc.c
+++ b/drivers/memory/tegra/tegra20-emc.c
@@ -1021,15 +1021,13 @@ static int tegra_emc_interconnect_init(struct tegra_emc *emc)
 	emc->provider.aggregate = soc->icc_ops->aggregate;
 	emc->provider.xlate_extended = emc_of_icc_xlate_extended;
 
-	err = icc_provider_add(&emc->provider);
-	if (err)
-		goto err_msg;
+	icc_provider_init(&emc->provider);
 
 	/* create External Memory Controller node */
 	node = icc_node_create(TEGRA_ICC_EMC);
 	if (IS_ERR(node)) {
 		err = PTR_ERR(node);
-		goto del_provider;
+		goto err_msg;
 	}
 
 	node->name = "External Memory Controller";
@@ -1050,12 +1048,14 @@ static int tegra_emc_interconnect_init(struct tegra_emc *emc)
 	node->name = "External Memory (DRAM)";
 	icc_node_add(node, &emc->provider);
 
+	err = icc_provider_register(&emc->provider);
+	if (err)
+		goto remove_nodes;
+
 	return 0;
 
 remove_nodes:
 	icc_nodes_remove(&emc->provider);
-del_provider:
-	icc_provider_del(&emc->provider);
 err_msg:
 	dev_err(emc->dev, "failed to initialize ICC: %d\n", err);
 
-- 
2.39.1

Re: [PATCH 19/23] memory: tegra20-emc: fix interconnect registration race

[Krzysztof Kozlowski]

On 01/02/2023 11:15, Johan Hovold wrote:
> The current interconnect provider registration interface is inherently
> racy as nodes are not added until the after adding the provider. This
> can specifically cause racing DT lookups to fail.
> 
> Switch to using the new API where the provider is not registered until
> after it has been fully initialised.
> 
> Fixes: d5ef16ba5fbe ("memory: tegra20: Support interconnect framework")
> Cc: stable@vger.kernel.org      # 5.11
> Cc: Dmitry Osipenko <digetx@gmail.com>
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>


Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Best regards,
Krzysztof

[PATCH 20/23] memory: tegra30-emc: fix interconnect registration race

[Johan Hovold]

The current interconnect provider registration interface is inherently
racy as nodes are not added until the after adding the provider. This
can specifically cause racing DT lookups to fail.

Switch to using the new API where the provider is not registered until
after it has been fully initialised.

Fixes: d5ef16ba5fbe ("memory: tegra20: Support interconnect framework")
Cc: stable@vger.kernel.org      # 5.11
Cc: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 drivers/memory/tegra/tegra30-emc.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/memory/tegra/tegra30-emc.c b/drivers/memory/tegra/tegra30-emc.c
index 77706e9bc543..c91e9b7e2e01 100644
--- a/drivers/memory/tegra/tegra30-emc.c
+++ b/drivers/memory/tegra/tegra30-emc.c
@@ -1533,15 +1533,13 @@ static int tegra_emc_interconnect_init(struct tegra_emc *emc)
 	emc->provider.aggregate = soc->icc_ops->aggregate;
 	emc->provider.xlate_extended = emc_of_icc_xlate_extended;
 
-	err = icc_provider_add(&emc->provider);
-	if (err)
-		goto err_msg;
+	icc_provider_init(&emc->provider);
 
 	/* create External Memory Controller node */
 	node = icc_node_create(TEGRA_ICC_EMC);
 	if (IS_ERR(node)) {
 		err = PTR_ERR(node);
-		goto del_provider;
+		goto err_msg;
 	}
 
 	node->name = "External Memory Controller";
@@ -1562,12 +1560,14 @@ static int tegra_emc_interconnect_init(struct tegra_emc *emc)
 	node->name = "External Memory (DRAM)";
 	icc_node_add(node, &emc->provider);
 
+	err = icc_provider_register(&emc->provider);
+	if (err)
+		goto remove_nodes;
+
 	return 0;
 
 remove_nodes:
 	icc_nodes_remove(&emc->provider);
-del_provider:
-	icc_provider_del(&emc->provider);
 err_msg:
 	dev_err(emc->dev, "failed to initialize ICC: %d\n", err);
 
-- 
2.39.1

Re: [PATCH 20/23] memory: tegra30-emc: fix interconnect registration race

[Krzysztof Kozlowski]

On 01/02/2023 11:15, Johan Hovold wrote:
> The current interconnect provider registration interface is inherently
> racy as nodes are not added until the after adding the provider. This
> can specifically cause racing DT lookups to fail.
> 
> Switch to using the new API where the provider is not registered until
> after it has been fully initialised.
> 
> Fixes: d5ef16ba5fbe ("memory: tegra20: Support interconnect framework")
> Cc: stable@vger.kernel.org      # 5.11
> Cc: Dmitry Osipenko <digetx@gmail.com>
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---


Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Best regards,
Krzysztof