kernel.git/drivers/acpi/power.c, branch linux-4.4.y

ACPI: power: Skip duplicate power resource references in _PRx

2019-01-16T21:16:12Z

commit 7d7b467cb95bf29597b417d4990160d4ea6d69b9 upstream. Some ACPI tables contain duplicate power resource references like this: Name (_PR0, Package (0x04) // _PR0: Power Resources for D0 { P28P, P18P, P18P, CLK4 }) This causes a WARN_ON in sysfs_add_link_to_group() because we end up adding a link to the same acpi_device twice: sysfs: cannot create duplicate filename '/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/808622C1:00/OVTI2680:00/power_resources_D0/LNXPOWER:0a' CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.19.12-301.fc29.x86_64 #1 Hardware name: Insyde CherryTrail/Type2 - Board Product Name, BIOS jumperx.T87.KFBNEEA02 04/13/2016 Call Trace: dump_stack+0x5c/0x80 sysfs_warn_dup.cold.3+0x17/0x2a sysfs_do_create_link_sd.isra.2+0xa9/0xb0 sysfs_add_link_to_group+0x30/0x50 acpi_power_expose_list+0x74/0xa0 acpi_power_add_remove_device+0x50/0xa0 acpi_add_single_object+0x26b/0x5f0 acpi_bus_check_add+0xc4/0x250 ... To address this issue, make acpi_extract_power_resources() check for duplicates and simply skip them when found. Cc: All applicable Signed-off-by: Hans de Goede [ rjw: Subject & changelog, comments ] Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

ACPI / power: Avoid maybe-uninitialized warning

2017-04-27T07:09:33Z

commit fe8c470ab87d90e4b5115902dd94eced7e3305c3 upstream. gcc -O2 cannot always prove that the loop in acpi_power_get_inferred_state() is enterered at least once, so it assumes that cur_state might not get initialized: drivers/acpi/power.c: In function 'acpi_power_get_inferred_state': drivers/acpi/power.c:222:9: error: 'cur_state' may be used uninitialized in this function [-Werror=maybe-uninitialized] This sets the variable to zero at the start of the loop, to ensure that there is well-defined behavior even for an empty list. This gets rid of the warning. The warning first showed up when the -Os flag got removed in a bug fix patch in linux-4.11-rc5. I would suggest merging this addon patch on top of that bug fix to avoid introducing a new warning in the stable kernels. Fixes: 61b79e16c68d (ACPI: Fix incompatibility with mcount-based function graph tracing) Signed-off-by: Arnd Bergmann Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

Merge branch 'acpi-pm'

2015-09-01T01:38:43Z

* acpi-pm: ACPI / bus: Move duplicate code to a separate new function mfd: Add support for Intel Sunrisepoint LPSS devices dmaengine: add a driver for Intel integrated DMA 64-bit mfd: make mfd_remove_devices() iterate in reverse order driver core: implement device_for_each_child_reverse() klist: implement klist_prev() Driver core: wakeup the parent device before trying probe ACPI / PM: Attach ACPI power domain only once PM / QoS: Make it possible to expose device latency tolerance to userspace ACPI / PM: Update the copyright notice and description of power.c

ACPI / PM: Update the copyright notice and description of power.c

2015-07-16T00:01:28Z

The description and copyright notice of drivers/acpi/power.c is out of date, so update it as appropriate. Signed-off-by: Rafael J. Wysocki

ACPI: Remove FSF mailing addresses

2015-07-08T00:27:32Z

There is no need to carry potentially outdated Free Software Foundation mailing address in file headers since the COPYING file includes it. Signed-off-by: Jarkko Nikula Signed-off-by: Rafael J. Wysocki

ACPI / PM: Turn power resources on and off in the right order during resume

2015-05-25T21:59:54Z

According to Section 7.2 of ACPI 6.0, power resources should always be enabled and disabled in order given by the "resourceorder" field of the corresponding Power Resource objects: "Power Resource levels are enabled from low values to high values and are disabled from high values to low values." However, this is not what happens during system resume, because in that case the enabling/disabling is carried out in the power resource registration order which may not reflect the ordering required by the platform. For this reason, make the ordering of the global list of all power resources in the system (used by the system resume code) reflect the one given by the "resourceorder" attributes of the Power Resource objects in the ACPI namespace and modify acpi_resume_power_resources() to walk the list in the reverse order when turning off the power resources that had been off before the system was suspended. Signed-off-by: Rafael J. Wysocki

ACPI / PM: Rework device power management to follow ACPI 6

2015-05-15T23:55:35Z

The ACPI 6 specification has made some changes in the device power management area. In particular: * The D3hot power state is now supposed to be always available (instead of D3cold) and D3cold is only regarded as valid if the _PR3 object is present for the given device. * The required ordering of transitions into power states deeper than D0 is now such that for a transition into state Dx the _PSx method is supposed to be executed first, if present, and the states of the power resources the device depends on are supposed to be changed after that. * It is now explicitly forbidden to transition devices from lower-power (deeper) into higher-power (shallower) power states other than D0. Those changes have been made so the specification reflects the Windows' device power management code that the vast majority of systems using ACPI is validated against. To avoid artificial differences in ACPI device power management between Windows and Linux, modify the ACPI device power management code to follow the new specification. Add comments explaining the code flow in some unclear places. This only may affect some real corner cases in which the OS behavior expected by the firmware is different from the Windows one, but that's quite unlikely. The transition ordering change affects transitions to D1 and D2 which are rarely used (if at all) and into D3hot and D3cold for devices actually having _PR3, but those are likely to be validated against Windows anyway. The other changes may affect code calling acpi_device_get_power() or acpi_device_update_power() where ACPI_STATE_D3_HOT may be returned instead of ACPI_STATE_D3_COLD (that's why the ACPI fan driver needs to be updated too) and since transitions into ACPI_STATE_D3_HOT may remove power now, it is better to avoid this one in acpi_pm_device_sleep_state() if the "no power off" PM QoS flag is set. The only existing user of acpi_device_can_poweroff() really cares about the case when _PR3 is present, so the change in that function should not cause any problems to happen too. A plus is that PCI_D3hot can be mapped to ACPI_STATE_D3_HOT now and the compatibility with older systems should be covered automatically. In any case, if any real problems result from this, it still will be better to follow the Windows' behavior (which now is reflected by the specification too) in general and handle the cases when it doesn't work via quirks. Signed-off-by: Rafael J. Wysocki

ACPI / PM: Drop stale comment from acpi_power_transition()

2015-05-08T20:41:05Z

An old comment in acpi_power_transition() indicates that support for ordering power resources needs to be added, but the current code handles that already. Drop the comment to avoid confusion. Signed-off-by: Rafael J. Wysocki

ACPI: Remove duplicate definitions of PREFIX

2014-03-19T01:01:57Z

We already have a macro for PREFIX of "ACPI: " in drivers/acpi/internal.h, so remove the duplicate ones in ACPI drivers when internal.h is included. Signed-off-by: Hanjun Guo Signed-off-by: Rafael J. Wysocki

ACPI: Clean up inclusions of ACPI header files

2013-12-07T00:03:14Z

Replace direct inclusions of , and , which are incorrect, with inclusions and remove some inclusions of those files that aren't necessary. First of all, , and should not be included directly from any files that are built for CONFIG_ACPI unset, because that generally leads to build warnings about undefined symbols in !CONFIG_ACPI builds. For CONFIG_ACPI set, includes those files and for CONFIG_ACPI unset it provides stub ACPI symbols to be used in that case. Second, there are ordering dependencies between those files that always have to be met. Namely, it is required that be included prior to so that the acpi_pci_root declarations the latter depends on are always there. And which provides basic ACPICA type declarations should always be included prior to any other ACPI headers in CONFIG_ACPI builds. That also is taken care of including as appropriate. Signed-off-by: Lv Zheng Cc: Greg Kroah-Hartman Cc: Matthew Garrett Cc: Tony Luck Cc: "H. Peter Anvin" Acked-by: Bjorn Helgaas (drivers/pci stuff) Acked-by: Konrad Rzeszutek Wilk (Xen stuff) Signed-off-by: Rafael J. Wysocki