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: Andres Rodriguez <andresx7@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Luis 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: Luis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/base/firmware_loader/main.c b/drivers/base/firmware_loader/main.c
index abdc4e4..0943e70 100644
--- a/drivers/base/firmware_loader/main.c
+++ b/drivers/base/firmware_loader/main.c
@@ -632,6 +632,33 @@ 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
* @name: name of firmware file