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

ACPI: scan: Make acpi_bus_get_device() clear return pointer on error

2021-01-30T12:25:54+00:00

commit 78a18fec5258c8df9435399a1ea022d73d3eceb9 upstream. Set the acpi_device pointer which acpi_bus_get_device() returns-by- reference to NULL on errors. We've recently had 2 cases where callers of acpi_bus_get_device() did not properly error check the return value, so set the returned- by-reference acpi_device pointer to NULL, because at least some callers of acpi_bus_get_device() expect that to be done on errors. [ rjw: This issue was exposed by commit 71da201f38df ("ACPI: scan: Defer enumeration of devices with _DEP lists") which caused it to be much more likely to occur on some systems, but the real defect had been introduced by an earlier commit. ] Fixes: 40e7fcb19293 ("ACPI: Add _DEP support to fix battery issue on Asus T100TA") Fixes: bcfcd409d4db ("usb: split code locating ACPI companion into port and device") Reported-by: Pierre-Louis Bossart Tested-by: Pierre-Louis Bossart Diagnosed-by: Rafael J. Wysocki Signed-off-by: Hans de Goede Cc: All applicable [ rjw: Subject and changelog edits ] Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

ACPI: PM: Avoid using power resources if there are none for D0

2020-06-20T08:23:16+00:00

commit 956ad9d98b73f59e442cc119c98ba1e04e94fe6d upstream. As recently reported, some platforms provide a list of power resources for device power state D3hot, through the _PR3 object, but they do not provide a list of power resources for device power state D0. Among other things, this causes acpi_device_get_power() to return D3hot as the current state of the device in question if all of the D3hot power resources are "on", because it sees the power_resources flag set and calls acpi_power_get_inferred_state() which finds that D3hot is the shallowest power state with all of the associated power resources turned "on", so that's what it returns. Moreover, that value takes precedence over the acpi_dev_pm_explicit_get() return value, because it means a deeper power state. The device may very well be in D0 physically at that point, however. Moreover, the presence of _PR3 without _PR0 for a given device means that only one D3-level power state can be supported by it. Namely, because there are no power resources to turn "off" when transitioning the device from D0 into D3cold (which should be supported since _PR3 is present), the evaluation of _PS3 should be sufficient to put it straight into D3cold, but this means that the effect of turning "on" the _PR3 power resources is unclear, so it is better to avoid doing that altogether. Consequently, there is no practical way do distinguish D3cold from D3hot for the device in question and the power states of it can be labeled so that D3hot is the deepest supported one (and Linux assumes that putting a device into D3hot via ACPI may cause power to be removed from it anyway, for legacy reasons). To work around the problem described above modify the ACPI enumeration of devices so that power resources are only used for device power management if the list of D0 power resources is not empty and make it mart D3cold as supported only if that is the case and the D3hot list of power resources is not empty too. Fixes: ef85bdbec444 ("ACPI / scan: Consolidate extraction of power resources lists") Link: https://bugzilla.kernel.org/show_bug.cgi?id=205057 Link: https://lore.kernel.org/linux-acpi/20200603194659.185757-1-hdegoede@redhat.com/ Reported-by: Hans de Goede Tested-by: Hans de Goede Tested-by: youling257@gmail.com Cc: 3.10+ # 3.10+ Signed-off-by: Rafael J. Wysocki Reviewed-by: Hans de Goede Signed-off-by: Greg Kroah-Hartman

ACPI / drivers: replace acpi_probe_lock spinlock with mutex

2016-09-07T06:32:45+00:00

commit 5331d9cab32ef640b4cd38a43b0858874fbb7168 upstream. Commit e647b532275b ("ACPI: Add early device probing infrastructure") introduced code that allows inserting driver specific struct acpi_probe_entry probe entries into ACPI linker sections (one per-subsystem, eg irqchip, clocksource) that are then walked to retrieve the data and function hooks required to probe the respective kernel components. Probing for all entries in a section is triggered through the __acpi_probe_device_table() function, that in turn, according to the table ID a given probe entry reports parses the table with the function retrieved from the respective section structures (ie struct acpi_probe_entry). Owing to the current ACPI table parsing implementation, the __acpi_probe_device_table() function has to share global variables with the acpi_match_madt() function, so in order to guarantee mutual exclusion locking is required between the two functions. Current kernel code implements the locking through the acpi_probe_lock spinlock; this has the side effect of requiring all code called within the lock (ie struct acpi_probe_entry.probe_{table/subtbl} hooks) not to sleep. However, kernel subsystems that make use of the early probing infrastructure are relying on kernel APIs that may sleep (eg irq_domain_alloc_fwnode(), among others) in the function calls pointed at by struct acpi_probe_entry.{probe_table/subtbl} entries (eg gic_v2_acpi_init()), which is a bug. Since __acpi_probe_device_table() is called from context that is allowed to sleep the acpi_probe_lock spinlock can be replaced with a mutex; this fixes the issue whilst still guaranteeing mutual exclusion. Signed-off-by: Lorenzo Pieralisi Fixes: e647b532275b (ACPI: Add early device probing infrastructure) Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

Merge branch 'acpi-pci'

2015-11-07T00:30:10+00:00

* acpi-pci: PCI: ACPI: Add support for PCI device DMA coherency PCI: OF: Move of_pci_dma_configure() to pci_dma_configure() of/pci: Fix pci_get_host_bridge_device leak device property: ACPI: Remove unused DMA APIs device property: ACPI: Make use of the new DMA Attribute APIs device property: Adding DMA Attribute APIs for Generic Devices ACPI: Adding DMA Attribute APIs for ACPI Device device property: Introducing enum dev_dma_attr ACPI: Honor ACPI _CCA attribute setting Conflicts: drivers/crypto/ccp/ccp-platform.c

ACPI: Adding DMA Attribute APIs for ACPI Device

2015-11-07T00:29:21+00:00

Adding acpi_get_dma_attr() to query DMA attributes of ACPI devices. It returns the enum dev_dma_attr, which communicates DMA information more clearly. This API replaces the acpi_check_dma(), which will be removed in subsequent patch. This patch also provides a convenient function, acpi_dma_supported(), to check DMA support of the specified ACPI device. Signed-off-by: Suravee Suthikulpanit Acked-by: Bjorn Helgaas Reviewed-by: Hanjun Guo Signed-off-by: Rafael J. Wysocki

Merge branch 'acpi-init'

2015-10-25T21:55:14+00:00

* acpi-init: clocksource: cosmetic: Drop OF 'dependency' from symbols clocksource / arm_arch_timer: Convert to ACPI probing clocksource: Add new CLKSRC_{PROBE,ACPI} config symbols clocksource / ACPI: Add probing infrastructure for ACPI-based clocksources irqchip / GIC: Convert the GIC driver to ACPI probing irqchip / ACPI: Add probing infrastructure for ACPI-based irqchips ACPI: Add early device probing infrastructure

Merge branches 'acpi-scan', 'acpi-tables', 'acpi-ec' and 'acpi-assorted'

2015-10-25T21:54:46+00:00

* acpi-scan: ACPI / scan: use kstrdup_const() in acpi_add_id() ACPI / scan: constify struct acpi_hardware_id::id ACPI / scan: constify first argument of struct acpi_scan_handler::match * acpi-tables: ACPI / tables: test the correct variable x86, ACPI: Handle apic/x2apic entries in MADT in correct order ACPI / tables: Add acpi_subtable_proc to ACPI table parsers * acpi-ec: ACPI / EC: Fix a race issue in acpi_ec_guard_event() ACPI / EC: Fix query handler related issues * acpi-assorted: ACPI: change acpi_sleep_proc_init() to return void ACPI: change init_acpi_device_notify() to return void

ACPI: Add early device probing infrastructure

2015-10-01T00:18:38+00:00

IRQ controllers and timers are the two types of device the kernel requires before being able to use the device driver model. ACPI so far lacks a proper probing infrastructure similar to the one we have with DT, where we're able to declare IRQ chips and clocksources inside the driver code, and let the core code pick it up and call us back on a match. This leads to all kind of really ugly hacks all over the arm64 code and even in the ACPI layer. In order to allow some basic probing based on the ACPI tables, introduce "struct acpi_probe_entry" which contains just enough data and callbacks to match a table, an optional subtable, and call a probe function. A driver can, at build time, register itself and expect being called if the right entry exists in the ACPI table. A acpi_probe_device_table() is provided, taking an identifier for a set of acpi_prove_entries, and iterating over the registered entries. Signed-off-by: Marc Zyngier Reviewed-by: Lorenzo Pieralisi Reviewed-by: Hanjun Guo Acked-by: Thomas Gleixner Tested-by: Hanjun Guo Signed-off-by: Rafael J. Wysocki

ACPI / scan: use kstrdup_const() in acpi_add_id()

2015-09-15T00:59:07+00:00

Empirically, acpi_add_id is mostly called with string literals, so using kstrdup_const for initializing struct acpi_hardware_id::id saves a little run-time memory and a string copy. Signed-off-by: Rasmus Villemoes Signed-off-by: Rafael J. Wysocki

ACPI / scan: constify struct acpi_hardware_id::id

2015-09-15T00:57:55+00:00

This is preparation for using kstrdup_const to initialize that member. Signed-off-by: Rasmus Villemoes Signed-off-by: Rafael J. Wysocki