Use kstrdup rather than duplicating its implementation The semantic patch that makes this output is available in scripts/coccinelle/api/kstrdup.cocci. More information about semantic patching is available at http://coccinelle.lip6.fr/ Signed-off-by: Thomas Meyer <thomas@m3y3r.de> Signed-off-by: Len Brown <len.brown@intel.com>
There is at least one BIOS with a DSDT containing a power resource object with a _PR0 entry pointing back to that power resource. In consequence, while registering that power resource acpi_bus_get_power_flags() sees that it depends on itself and tries to register it again, which leads to an infinitely deep recurrence. This problem was introduced by commit bf325f9538d8c89312be305b9779e (ACPI / PM: Register power resource devices as soon as they are needed). To fix this problem use the observation that power resources cannot be power manageable and prevent acpi_bus_get_power_flags() from being called for power resource objects. References: https://bugzilla.kernel.org/show_bug.cgi?id=31872 Reported-and-tested-by: Pascal Dormeau <pdormeau@free.fr> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Len Brown <lenb@kernel.org> Cc: stable@kernel.org
The wakeup.run_wake_count ACPI device field is only used by the PCI runtime PM code to "protect" devices from being prepared for generating wakeup signals more than once in a row. However, it really doesn't provide any protection, because (1) all of the functions it is supposed to protect use their own reference counters effectively ensuring that the device will be set up for generating wakeup signals just once and (2) the PCI runtime PM code uses wakeup.run_wake_count in a racy way, since nothing prevents acpi_dev_run_wake() from being called concurrently from two different threads for the same device. Remove the wakeup.run_wake_count ACPI device field which is unnecessary, confusing and used in a wrong way. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
The wake_capable ACPI device flag is not necessary, because it is only used in scan.c for recording the information that _PRW is present for the given device. That information is only used by acpi_add_single_object() to decide whether or not to call acpi_bus_get_wakeup_device_flags(), so the flag may be dropped if the _PRW check is moved to acpi_bus_get_wakeup_device_flags(). Moreover, acpi_bus_get_wakeup_device_flags() always returns 0, so it really should be void. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Len Brown <len.brown@intel.com>
Before evaluating _PRW for devices that are reported as inactive or not present by their _STA control methods we should check if those methods are actually present (otherwise the evaulation of _PRW will obviously fail and a scary message will be printed unnecessarily). Reported-by: Andreas Mohr <andi@lisas.de> Reported-by: Maciej Rutecki <maciej.rutecki@gmail.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Len Brown <len.brown@intel.com>
Depending on the organization of the ACPI namespace, power resource device objects may generally be scanned after the "regular" device objects that they are referred from through _PRn. This, in turn, may cause acpi_bus_get_power_flags() to attempt to access them through acpi_bus_init_power() before they are registered (and initialized by acpi_power_driver). [This is not a theoretical issue, it actually happens for one PnP device on my testbed HP nx6325.] To fix this problem, make acpi_bus_get_power_flags() attempt to register power resource devices as soon as they have been found in the _PRn output for any other devices. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Len Brown <len.brown@intel.com>
The ACPI device driver used for handling power resources, acpi_power_driver, creates a struct acpi_power_resource object for each ACPI device representing a power resource. These objects are then used when setting and reading the power states of devices using the corresponding power resources. Unfortunately, acpi_power_driver is registered after acpi_scan_init() that may add devices using the power resources before acpi_power_driver has a chance to create struct acpi_power_resource objects for them (specifically, the power resources may be referred to during the scanning process through acpi_bus_get_power() before they have been initialized). As the first step towards fixing this issue, move the registration of acpi_power_driver into acpi_scan_init() so that power resource devices can be initialized by it as soon as they have been found in the namespace. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Len Brown <len.brown@intel.com>
Add function acpi_bus_init_power() for getting the initial power state of an ACPI device and reference counting its power resources as appropriate. Make acpi_bus_get_power_flags() use the new function instead of acpi_bus_get_power() that updates device->power.state without reference counting the device's power resources. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Len Brown <len.brown@intel.com>