lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Tue, 20 Aug 2013 17:03:36 +0300
From:	Mika Westerberg <mika.westerberg@...ux.intel.com>
To:	linux-i2c@...r.kernel.org
Cc:	Wolfram Sang <wsa@...-dreams.de>,
	"Rafael J. Wysocki" <rafael.j.wysocki@...el.com>,
	linux-acpi@...r.kernel.org, linux-kernel@...r.kernel.org,
	Lv Zheng <lv.zheng@...el.com>, Aaron Lu <aaron.lu@...el.com>,
	Mika Westerberg <mika.westerberg@...ux.intel.com>
Subject: [RFC PATCH 2/2] i2c: attach/detach I2C client device to the ACPI power domain

From: Lv Zheng <lv.zheng@...el.com>

If the I2C client device is enumerated from ACPI namespace it might have
ACPI methods that needs to be called in order to transition the device to
a different power states (such as _PSx).

Implement this for I2C client devices by checking if the device has an ACPI
handle and if that's the case, attach it to the ACPI power domain. In
addition we make sure that the device is fully powered when its ->probe()
function gets called.

For non-ACPI devices this patch is a no-op.

Signed-off-by: Lv Zheng <lv.zheng@...el.com>
Signed-off-by: Mika Westerberg <mika.westerberg@...ux.intel.com>
---
 drivers/i2c/i2c-core.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 8fad5ac..fdf086b 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -257,6 +257,9 @@ static int i2c_device_probe(struct device *dev)
 	/* Make sure the adapter is active */
 	pm_runtime_get_sync(&client->adapter->dev);
 
+	if (ACPI_HANDLE(&client->dev))
+		acpi_dev_pm_attach(&client->dev, true);
+
 	/*
 	 * Enable runtime PM for the client device. If the client wants to
 	 * participate on runtime PM it should call pm_runtime_put() in its
@@ -278,6 +281,9 @@ static int i2c_device_probe(struct device *dev)
 		pm_runtime_disable(&client->dev);
 		pm_runtime_set_suspended(&client->dev);
 		pm_runtime_put_noidle(&client->dev);
+
+		if (ACPI_HANDLE(&client->dev))
+			acpi_dev_pm_detach(&client->dev, true);
 	}
 
 	pm_runtime_put(&client->adapter->dev);
@@ -314,6 +320,9 @@ static int i2c_device_remove(struct device *dev)
 	pm_runtime_set_suspended(&client->dev);
 	pm_runtime_put_noidle(&client->dev);
 
+	if (ACPI_HANDLE(&client->dev))
+		acpi_dev_pm_detach(&client->dev, true);
+
 	pm_runtime_put(&client->adapter->dev);
 	return status;
 }
-- 
1.8.4.rc2

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists