Messages in this thread Patch in this message | | | From | Ulf Hansson <> | Subject | [PATCH] PM: domains: Don't attach a device to genpd that corresponds to a provider | Date | Fri, 9 Jul 2021 14:56:11 +0200 |
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According to the common power domain DT bindings, a power domain provider must have a "#power-domain-cells" property in its OF node. Additionally, if a provider has a "power-domains" property, it means that it has a parent domain.
It has turned out that some OF nodes that represents a genpd provider may also be compatible with a regular platform device. This leads to, during probe, genpd_dev_pm_attach(), genpd_dev_pm_attach_by_name() and genpd_dev_pm_attach_by_id() tries to attach the corresponding struct device to the genpd provider's parent domain, which is wrong. Instead the genpd provider should only assign a parent domain, through pm_genpd_add_subdomain() or of_genpd_add_subdomain().
Let's fix this problem in genpd by checking for the "#power-domain-cells" property in the OF node for the struct device that is about to be attached.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> ---
This turned up when I was reviewing a couple of genpd realted Qcom patches [1], from Dmitry Baryshkov (on cc).
I haven't been able to run much tests, so help with that would be greatly appreciated. If someone encounter issues, I am happy to help to fix those.
Kind regards Ulf Hansson
[1] https://lkml.org/lkml/2021/7/9/7 https://lkml.org/lkml/2021/7/9/8
--- drivers/base/power/domain.c | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index a934c679e6ce..21991fb56a19 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -2699,6 +2699,10 @@ int genpd_dev_pm_attach(struct device *dev) if (!dev->of_node) return 0; + /* Don't try to attach a genpd provider. */ + if (of_find_property(dev->of_node, "#power-domain-cells", NULL)) + return NULL; + /* * Devices with multiple PM domains must be attached separately, as we * can only attach one PM domain per device. @@ -2737,6 +2741,10 @@ struct device *genpd_dev_pm_attach_by_id(struct device *dev, if (!dev->of_node) return NULL; + /* Don't try to attach a genpd provider. */ + if (of_find_property(dev->of_node, "#power-domain-cells", NULL)) + return NULL; + /* Verify that the index is within a valid range. */ num_domains = of_count_phandle_with_args(dev->of_node, "power-domains", "#power-domain-cells"); -- 2.25.1
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