diff mbox series

[v2,04/23] interconnect: imx: fix registration race

Message ID 20230306075651.2449-5-johan+linaro@kernel.org
State Accepted
Commit 9fbd35520f1f7f3cbe1873939a27ad9b009f21f9
Headers show
Series interconnect: fix racy provider registration | expand

Commit Message

Johan Hovold March 6, 2023, 7:56 a.m. UTC
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: Alexandre Bailon <abailon@baylibre.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Tested-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 drivers/interconnect/imx/imx.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

Comments

Luca Ceresoli March 7, 2023, 9:43 a.m. UTC | #1
On Mon,  6 Mar 2023 08:56:32 +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: Alexandre Bailon <abailon@baylibre.com>
> Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
> Tested-by: Luca Ceresoli <luca.ceresoli@bootlin.com>

v2 works just as well, so my Tested-by is confirmed. Maybe it's useful
mentioning the hardware used for testing so:

[Tested on i.MX8MP using an MSC SM2-MB-EP1 Board]
Tested-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Johan Hovold March 7, 2023, 10:25 a.m. UTC | #2
On Tue, Mar 07, 2023 at 10:43:24AM +0100, Luca Ceresoli wrote:
> On Mon,  6 Mar 2023 08:56:32 +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: Alexandre Bailon <abailon@baylibre.com>
> > Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
> > Tested-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
> 
> v2 works just as well, so my Tested-by is confirmed. Maybe it's useful
> mentioning the hardware used for testing so:
> 
> [Tested on i.MX8MP using an MSC SM2-MB-EP1 Board]
> Tested-by: Luca Ceresoli <luca.ceresoli@bootlin.com>

Thanks for reconfirming. Looks like Georgi has picked these up for
6.3-rc now.

Johan
diff mbox series

Patch

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);