Commit 7dcc0134 authored by Andres Rodriguez's avatar Andres Rodriguez Committed by Greg Kroah-Hartman
Browse files

firmware: add firmware_request_nowarn() - load firmware without warnings 

Currently the firmware loader only exposes one silent path for querying
optional firmware, and that is firmware_request_direct(). This function
also disables the sysfs fallback mechanism, which might not always be the
desired behaviour [0].

This patch introduces a variations of request_firmware() that enable the
caller to disable the undesired warning messages but enables the sysfs
fallback mechanism. This is equivalent to adding FW_OPT_NO_WARN to the
old behaviour.

[0]: https://git.kernel.org/linus/c0cc00f250e1



Signed-off-by: default avatarAndres Rodriguez <andresx7@gmail.com>
Reviewed-by: default avatarKees Cook <keescook@chromium.org>
Acked-by: default avatarLuis R. Rodriguez <mcgrof@kernel.org>
[mcgrof: used the old API calls as the full rename is not done yet, and
 add the caller for when FW_LOADER is disabled, enhance documentation ]
Signed-off-by: default avatarLuis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 27d5d7dc

Documentation/driver-api/firmware/request_firmware.rst

+5 −0
Original line number Diff line number Diff line
@@ -20,6 +20,11 @@ request_firmware 
.. kernel-doc:: drivers/base/firmware_loader/main.c

   :functions: request_firmware



firmware_request_nowarn

-----------------------

.. kernel-doc:: drivers/base/firmware_loader/main.c

   :functions: firmware_request_nowarn



request_firmware_direct

-----------------------

.. kernel-doc:: drivers/base/firmware_loader/main.c

drivers/base/firmware_loader/main.c

+27 −0
Original line number Diff line number Diff line
@@ -631,6 +631,33 @@ request_firmware(const struct firmware **firmware_p, const char *name, 
}

EXPORT_SYMBOL(request_firmware);



/**

 * firmware_request_nowarn() - request for an optional fw module

 * @firmware: pointer to firmware image

 * @name: name of firmware file

 * @device: device for which firmware is being loaded

 *

 * This function is similar in behaviour to request_firmware(), except

 * it doesn't produce warning messages when the file is not found.

 * The sysfs fallback mechanism is enabled if direct filesystem lookup fails,

 * however, however failures to find the firmware file with it are still

 * suppressed. It is therefore up to the driver to check for the return value

 * of this call and to decide when to inform the users of errors.

 **/

int firmware_request_nowarn(const struct firmware **firmware, const char *name,

			    struct device *device)

{

	int ret;



	/* Need to pin this module until return */

	__module_get(THIS_MODULE);

	ret = _request_firmware(firmware, name, device, NULL, 0,

				FW_OPT_UEVENT | FW_OPT_NO_WARN);

	module_put(THIS_MODULE);

	return ret;

}

EXPORT_SYMBOL_GPL(firmware_request_nowarn);



/**

 * request_firmware_direct() - load firmware directly without usermode helper

 * @firmware_p: pointer to firmware image

include/linux/firmware.h

+10 −0
Original line number Diff line number Diff line
@@ -42,6 +42,8 @@ struct builtin_fw { 
#if defined(CONFIG_FW_LOADER) || (defined(CONFIG_FW_LOADER_MODULE) && defined(MODULE))

int request_firmware(const struct firmware **fw, const char *name,

		     struct device *device);

int firmware_request_nowarn(const struct firmware **fw, const char *name,

			    struct device *device);

int request_firmware_nowait(

	struct module *module, bool uevent,

	const char *name, struct device *device, gfp_t gfp, void *context,
@@ -59,6 +61,14 @@ static inline int request_firmware(const struct firmware **fw, 
{

	return -EINVAL;

}



static inline int firmware_request_nowarn(const struct firmware **fw,

					  const char *name,

					  struct device *device)

{

	return -EINVAL;

}



static inline int request_firmware_nowait(

	struct module *module, bool uevent,

	const char *name, struct device *device, gfp_t gfp, void *context,

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