Re: [PATCH v4 2/8] ACPI: scan: Add function to fetch dependent of acpi device
From: "Rafael J. Wysocki" <rafael@kernel.org>
Date: 2021-05-20 18:33:37
Also in:
linux-acpi, linux-arm-kernel, linux-gpio, lkml, platform-driver-x86
On Thu, May 20, 2021 at 4:11 PM Daniel Scally [off-list ref] wrote:
quoted hunk ↗ jump to hunk
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> Signed-off-by: Daniel Scally <djrscally@gmail.com> --- Changes since v3: Both new functions were renamed. drivers/acpi/scan.c | 38 ++++++++++++++++++++++++++++++++++++++ include/acpi/acpi_bus.h | 1 + 2 files changed, 39 insertions(+)diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 195635c3462b..1a76fbdfa669 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c@@ -2105,6 +2105,21 @@ static void acpi_bus_attach(struct acpi_device *device, bool first_pass) device->handler->hotplug.notify_online(device); } +static int acpi_return_dep_dev(struct acpi_dep_data *dep, void *data)
What about calling this acpi_get_first_consumer_cb()?
+{
+ 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;And it can do the get_device() here, can't it? So maybe use acpi_bus_get_acpi_device() instead of acpi_bus_get_device()? Would be simpler.
quoted hunk ↗ jump to hunk
+ + return 1; +} + static int acpi_scan_clear_dep(struct acpi_dep_data *dep, void *data) { struct acpi_device *adev;@@ -2168,6 +2183,29 @@ void acpi_dev_clear_dependencies(struct acpi_device *supplier) } EXPORT_SYMBOL_GPL(acpi_dev_clear_dependencies); +/** + * acpi_dev_get_dependent_dev - Return ACPI device dependent on @supplier
And what about calling this acpi_get_first_consumer() ?
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+ * @supplier: Pointer to the dependee device + * + * Returns the first &struct acpi_device which declares itself dependent on + * @supplier via the _DEP buffer, parsed from the acpi_dep_list. + * + * The caller is responsible for putting the reference to adev when it is no + * longer needed. + */ +struct acpi_device *acpi_dev_get_dependent_dev(struct acpi_device *supplier) +{ + struct acpi_device *adev = NULL; + + acpi_walk_dep_device_list(supplier->handle, acpi_return_dep_dev, &adev); + + if (adev) + get_device(&adev->dev); + + 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 0b2c4f170f4d..68d378207704 100644 --- a/include/acpi/acpi_bus.h +++ b/include/acpi/acpi_bus.h@@ -692,6 +692,7 @@ 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_clear_dependencies(struct acpi_device *supplier); +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