diff options
| -rw-r--r-- | drivers/acpi/utils.c | 8 | ||||
| -rw-r--r-- | include/acpi/acpi_bus.h | 14 |
2 files changed, 20 insertions, 2 deletions
diff --git a/drivers/acpi/utils.c b/drivers/acpi/utils.c index 682edd913b3b..35c3b52fb6ad 100644 --- a/drivers/acpi/utils.c +++ b/drivers/acpi/utils.c @@ -832,7 +832,11 @@ EXPORT_SYMBOL(acpi_dev_present); * Return the next match of ACPI device if another matching device was present * at the moment of invocation, or NULL otherwise. * - * The caller is responsible to call put_device() on the returned device. + * FIXME: The function does not tolerate the sudden disappearance of @adev, e.g. + * in the case of a hotplug event. That said, the caller should ensure that + * this will never happen. + * + * The caller is responsible for invoking acpi_dev_put() on the returned device. * * See additional information in acpi_dev_present() as well. */ @@ -861,7 +865,7 @@ EXPORT_SYMBOL(acpi_dev_get_next_match_dev); * Return the first match of ACPI device if a matching device was present * at the moment of invocation, or NULL otherwise. * - * The caller is responsible to call put_device() on the returned device. + * The caller is responsible for invoking acpi_dev_put() on the returned device. * * See additional information in acpi_dev_present() as well. */ diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h index f28b097c658f..61937d243374 100644 --- a/include/acpi/acpi_bus.h +++ b/include/acpi/acpi_bus.h @@ -689,6 +689,20 @@ acpi_dev_get_next_match_dev(struct acpi_device *adev, const char *hid, const cha struct acpi_device * acpi_dev_get_first_match_dev(const char *hid, const char *uid, s64 hrv); +/** + * for_each_acpi_dev_match - iterate over ACPI devices that matching the criteria + * @adev: pointer to the matching ACPI device, NULL at the end of the loop + * @hid: Hardware ID of the device. + * @uid: Unique ID of the device, pass NULL to not check _UID + * @hrv: Hardware Revision of the device, pass -1 to not check _HRV + * + * The caller is responsible for invoking acpi_dev_put() on the returned device. + * + * FIXME: Due to above requirement there is a window that may invalidate @adev + * and next iteration will use a dangling pointer, e.g. in the case of a + * hotplug event. That said, the caller should ensure that this will never + * happen. + */ #define for_each_acpi_dev_match(adev, hid, uid, hrv) \ for (adev = acpi_dev_get_first_match_dev(hid, uid, hrv); \ adev; \ |