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.
Signed-off-by: Daniel Scally <[email protected]>
---
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;
+
+ 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)
+{
+ struct acpi_device *adev = NULL;
+
+ acpi_walk_dep_device_list(supplier->handle,
+ __acpi_dev_get_dependent_dev, &adev);
+
+ 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
On Mon, Feb 22, 2021 at 3:11 PM Daniel Scally <[email protected]> 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 <[email protected]>
Nit-picks below as usual :-)
> Signed-off-by: Daniel Scally <[email protected]>
> ---
> 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.
> +
> + 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.
> + 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