Re: [PATCH v3 2/6] ACPI: scan: Add function to fetch dependent of acpi device
From: Andy Shevchenko <hidden>
Date: 2021-02-22 14:17:32
Also in:
linux-acpi, linux-i2c, lkml, platform-driver-x86
On Mon, Feb 22, 2021 at 3:11 PM Daniel Scally [off-list ref] wrote:
In some ACPI tables we encounter, devices use the _DEP method to assert a dependence on other ACPI devices as opposed to the OpRegions that the specification intends. We need to be able to find those devices "from" the dependee, so add a callback and a wrapper to walk over the acpi_dep_list and return the dependent ACPI device.
Reviewed-by: Andy Shevchenko <redacted> Nit-picks below as usual :-)
quoted hunk ↗ jump to hunk
Signed-off-by: Daniel Scally <djrscally@gmail.com> --- Changes in v3: - Switched from a standalone function to a callback passed to acpi_walk_dep_device_list(). drivers/acpi/scan.c | 34 ++++++++++++++++++++++++++++++++++ include/acpi/acpi_bus.h | 1 + 2 files changed, 35 insertions(+)diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index c9e4190316ef..55626925261c 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c@@ -2093,6 +2093,21 @@ static void acpi_bus_attach(struct acpi_device *device, bool first_pass) device->handler->hotplug.notify_online(device); } +static int __acpi_dev_get_dependent_dev(struct acpi_dep_data *dep, void *data) +{ + struct acpi_device *adev; + int ret; + + ret = acpi_bus_get_device(dep->consumer, &adev); + if (ret) + /* If we don't find an adev then we want to continue parsing */ + return 0; + + *(struct acpi_device **)data = adev;
Hmm... I'm wondering if *(void **data) = adev; will compile and work. But on second thought the current code is more specific and explicit, which is good.
quoted hunk ↗ jump to hunk
+ + return 1; +} + static int __acpi_dev_flag_dependency_met(struct acpi_dep_data *dep, void *data) {@@ -2145,6 +2160,25 @@ void acpi_dev_flag_dependency_met(acpi_handle handle) } EXPORT_SYMBOL_GPL(acpi_dev_flag_dependency_met); +/** + * acpi_dev_get_dependent_dev - Return ACPI device dependent on @adev + * @adev: Pointer to the dependee device + * + * Returns the first &struct acpi_device which declares itself dependent on + * @adev via the _DEP buffer, parsed from the acpi_dep_list. + */
+struct acpi_device * +acpi_dev_get_dependent_dev(struct acpi_device *supplier)
I believe it will be okay to have it on one line
+{
+ struct acpi_device *adev = NULL;+ acpi_walk_dep_device_list(supplier->handle, + __acpi_dev_get_dependent_dev, &adev);
Ditto.
quoted hunk ↗ jump to hunk
+ return adev; +} +EXPORT_SYMBOL_GPL(acpi_dev_get_dependent_dev); + /** * acpi_bus_scan - Add ACPI device node objects in a given namespace scope. * @handle: Root of the namespace scope to scan.diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h index 91172af3a04d..5b14a9ae4ed5 100644 --- a/include/acpi/acpi_bus.h +++ b/include/acpi/acpi_bus.h@@ -690,6 +690,7 @@ static inline bool acpi_device_can_poweroff(struct acpi_device *adev) bool acpi_dev_hid_uid_match(struct acpi_device *adev, const char *hid2, const char *uid2); void acpi_dev_flag_dependency_met(acpi_handle handle); +struct acpi_device *acpi_dev_get_dependent_dev(struct acpi_device *supplier); struct acpi_device * acpi_dev_get_next_match_dev(struct acpi_device *adev, const char *hid, const char *uid, s64 hrv); struct acpi_device * --2.25.1
-- With Best Regards, Andy Shevchenko