[alsa-devel] [PATCH v3 01/10] ACPI / utils: Introduce acpi_dev_get_first_match_dev() helper

[Rafael J. Wysocki]

On Thu, Mar 28, 2019 at 6:17 PM Andy Shevchenko
<andriy.shevchenko at linux.intel.com> wrote:
>
> The acpi_dev_get_first_match_name() is missing put_device() call
> and thus keeping reference counting unbalanced.
>
> In order to fix the issue introduce a new helper to convert existing users
> one-by-one to a better API. And then remove the old one.
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko at linux.intel.com>
> Reviewed-by: Hans de Goede <hdegoede at redhat.com>

Any differences between this and the previous one?  I've queued up
that one already.

> ---
>  drivers/acpi/utils.c    | 24 ++++++++++++++++++++++--
>  include/acpi/acpi_bus.h |  3 +++
>  include/linux/acpi.h    |  6 ++++++
>  3 files changed, 31 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/acpi/utils.c b/drivers/acpi/utils.c
> index c4b06cc075f9..5a2bae2b6c3a 100644
> --- a/drivers/acpi/utils.c
> +++ b/drivers/acpi/utils.c
> @@ -739,6 +739,7 @@ EXPORT_SYMBOL(acpi_dev_found);
>
>  struct acpi_dev_match_info {
>         const char *dev_name;
> +       struct acpi_device *adev;
>         struct acpi_device_id hid[2];
>         const char *uid;
>         s64 hrv;
> @@ -759,6 +760,7 @@ static int acpi_dev_match_cb(struct device *dev, void *data)
>                 return 0;
>
>         match->dev_name = acpi_dev_name(adev);
> +       match->adev = adev;
>
>         if (match->hrv == -1)
>                 return 1;
> @@ -806,16 +808,34 @@ bool acpi_dev_present(const char *hid, const char *uid, s64 hrv)
>  EXPORT_SYMBOL(acpi_dev_present);
>
>  /**
> - * acpi_dev_get_first_match_name - Return name of first match of ACPI device
> + * acpi_dev_get_first_match_dev - Return the first match of ACPI device
>   * @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
>   *
> - * Return device name if a matching device was present
> + * 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.
> + *
>   * See additional information in acpi_dev_present() as well.
>   */
> +struct acpi_device *
> +acpi_dev_get_first_match_dev(const char *hid, const char *uid, s64 hrv)
> +{
> +       struct acpi_dev_match_info match = {};
> +       struct device *dev;
> +
> +       strlcpy(match.hid[0].id, hid, sizeof(match.hid[0].id));
> +       match.uid = uid;
> +       match.hrv = hrv;
> +
> +       dev = bus_find_device(&acpi_bus_type, NULL, &match, acpi_dev_match_cb);
> +       return dev ? match.adev : NULL;
> +}
> +EXPORT_SYMBOL(acpi_dev_get_first_match_dev);
> +
> +/* DEPRECATED, use acpi_dev_get_first_match_dev() instead */
>  const char *
>  acpi_dev_get_first_match_name(const char *hid, const char *uid, s64 hrv)
>  {
> diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
> index 0300374101cd..2063e9e2f384 100644
> --- a/include/acpi/acpi_bus.h
> +++ b/include/acpi/acpi_bus.h
> @@ -91,6 +91,9 @@ acpi_evaluate_dsm_typed(acpi_handle handle, const guid_t *guid, u64 rev,
>  bool acpi_dev_found(const char *hid);
>  bool acpi_dev_present(const char *hid, const char *uid, s64 hrv);
>
> +struct acpi_device *
> +acpi_dev_get_first_match_dev(const char *hid, const char *uid, s64 hrv);
> +
>  const char *
>  acpi_dev_get_first_match_name(const char *hid, const char *uid, s64 hrv);
>
> diff --git a/include/linux/acpi.h b/include/linux/acpi.h
> index d5dcebd7aad3..3e1d16b00513 100644
> --- a/include/linux/acpi.h
> +++ b/include/linux/acpi.h
> @@ -669,6 +669,12 @@ static inline bool acpi_dev_present(const char *hid, const char *uid, s64 hrv)
>         return false;
>  }
>
> +static inline struct acpi_device *
> +acpi_dev_get_first_match_dev(const char *hid, const char *uid, s64 hrv)
> +{
> +       return NULL;
> +}
> +
>  static inline const char *
>  acpi_dev_get_first_match_name(const char *hid, const char *uid, s64 hrv)
>  {
> --
> 2.20.1
>