From: Ulf Hansson <ulf.hansson@linaro.org>
To: "Rafael J . Wysocki" <rjw@rjwysocki.net>, linux-pm@vger.kernel.org
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>,
Stephen Boyd <sboyd@kernel.org>,
Saravana Kannan <saravanak@google.com>,
Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
Kevin Hilman <khilman@kernel.org>,
Geert Uytterhoeven <geert+renesas@glider.be>,
Ulf Hansson <ulf.hansson@linaro.org>,
linux-kernel@vger.kernel.org
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 [thread overview]
Message-ID: <20210709125611.135920-1-ulf.hansson@linaro.org> (raw)
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
next reply other threads:[~2021-07-09 12:56 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-09 12:56 Ulf Hansson [this message]
2021-07-09 13:06 ` [PATCH] PM: domains: Don't attach a device to genpd that corresponds to a provider Geert Uytterhoeven
2021-07-09 13:22 ` Ulf Hansson
2021-07-09 13:35 ` Geert Uytterhoeven
2021-07-09 13:48 ` Ulf Hansson
2021-07-09 13:57 ` Geert Uytterhoeven
2021-07-09 14:02 ` Ulf Hansson
2021-07-09 13:46 ` Bjorn Andersson
2021-07-09 13:58 ` Ulf Hansson
2021-07-09 14:16 ` Bjorn Andersson
2021-07-09 18:49 ` kernel test robot
2021-07-09 19:01 ` kernel test robot
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