Re: [PATCH 1/5] ACPICA: Add acpi_dev_present

From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: Lukas Wunner <lukas@wunner.de>
Cc: linux-acpi@vger.kernel.org, devel@acpica.org,
	platform-driver-x86@vger.kernel.org,
	Darren Hart <dvhart@infradead.org>,
	Corentin Chary <corentin.chary@gmail.com>,
	"Lee, Chun-Yi" <jlee@suse.com>,
	alsa-devel@alsa-project.org, Takashi Iwai <tiwai@suse.de>,
	Hui Wang <hui.wang@canonical.com>,
	Mark Brown <broonie@kernel.org>, Lv Zheng <lv.zheng@intel.com>,
	Robert Moore <robert.moore@intel.com>,
	David Box <david.e.box@linux.intel.com>
Subject: Re: [PATCH 1/5] ACPICA: Add acpi_dev_present
Date: Mon, 23 Nov 2015 23:34:38 +0100	[thread overview]
Message-ID: <2726545.001oM5V9lv@vostro.rjw.lan> (raw)
In-Reply-To: <d66501819cfa8f3d3b07708d3f20e3e20d07e4f8.1448282995.git.lukas@wunner.de>

On Monday, November 23, 2015 03:34:55 PM Lukas Wunner wrote:
> There are 7 drivers which call acpi_get_devices to check for the
> presence of a particular ACPI HID, each defining its own copy of
> a mostly identical callback.
> 
> Add acpi_dev_present, the ACPI equivalent to pci_dev_present,
> allowing us to deduplicate all that boilerplate in the drivers.
> 
> Signed-off-by: Lukas Wunner <lukas@wunner.de>

We have a general rule for ACPICA patches that they go in through upstream ACPICA.

So if you really want this changes in ACPICA, this is the way to handle it.

Now, of course, for that to happen, you should have CCed the ACPICA maintainers
too (now done).

Thanks,
Rafael

> ---
>  drivers/acpi/acpica/nsxfeval.c | 46 ++++++++++++++++++++++++++++++++++++++++++
>  include/acpi/acpixf.h          |  7 +++++++
>  2 files changed, 53 insertions(+)
> 
> diff --git a/drivers/acpi/acpica/nsxfeval.c b/drivers/acpi/acpica/nsxfeval.c
> index 6ee1e52..19293fa 100644
> --- a/drivers/acpi/acpica/nsxfeval.c
> +++ b/drivers/acpi/acpica/nsxfeval.c
> @@ -828,6 +828,52 @@ ACPI_EXPORT_SYMBOL(acpi_get_devices)
>  
>  /*******************************************************************************
>   *
> + * FUNCTION:    acpi_ns_dev_present_callback
> + *
> + * PARAMETERS:  Callback from acpi_get_devices
> + *
> + * RETURN:      Status
> + *
> + * DESCRIPTION: Minimal callback to be passed to acpi_get_devices which
> + *              performs no further filtering and terminates the search
> + *              immediately.
> + *
> + ******************************************************************************/
> +static acpi_status acpi_ns_dev_present_callback(acpi_handle handle, u32 level,
> +						void *context, void **retval)
> +{
> +	*(bool *)context = true;
> +	return AE_CTRL_TERMINATE;
> +}
> +
> +/*******************************************************************************
> + *
> + * FUNCTION:    acpi_dev_present
> + *
> + * PARAMETERS:  HID                 - HID to search for.
> + *
> + * RETURNS      True if a matching object of type Device was found.
> + *
> + * DESCRIPTION: Performs a walk of the namespace tree. When a matching object
> + *              of type Device is found, the search is terminated immediately.
> + *
> + ******************************************************************************/
> +
> +bool
> +acpi_dev_present(const char *HID)
> +{
> +	acpi_status status;
> +	bool found = false;
> +
> +	status = acpi_get_devices(HID, acpi_ns_dev_present_callback, &found,
> +				  NULL);
> +	return ACPI_SUCCESS(status) && found;
> +}
> +
> +ACPI_EXPORT_SYMBOL(acpi_dev_present)
> +
> +/*******************************************************************************
> + *
>   * FUNCTION:    acpi_attach_data
>   *
>   * PARAMETERS:  obj_handle          - Namespace node
> diff --git a/include/acpi/acpixf.h b/include/acpi/acpixf.h
> index 3aaaa86..f299347 100644
> --- a/include/acpi/acpixf.h
> +++ b/include/acpi/acpixf.h
> @@ -115,6 +115,11 @@
>  	prototype;
>  #endif
>  
> +#ifndef ACPI_EXTERNAL_RETURN_BOOL
> +#define ACPI_EXTERNAL_RETURN_BOOL(prototype) \
> +	prototype;
> +#endif
> +
>  /*****************************************************************************
>   *
>   * Public globals and runtime configuration options
> @@ -483,6 +488,8 @@ ACPI_EXTERNAL_RETURN_STATUS(acpi_status
>  					      acpi_walk_callback user_function,
>  					      void *context,
>  					      void **return_value))
> +ACPI_EXTERNAL_RETURN_BOOL(bool
> +			     acpi_dev_present(const char *HID))
>  ACPI_EXTERNAL_RETURN_STATUS(acpi_status
>  			     acpi_get_name(acpi_handle object, u32 name_type,
>  					   struct acpi_buffer *ret_path_ptr))
> 