1 files changed, 39 insertions, 14 deletions

diff --git a/drivers/base/firmware_loader/fallback.c b/drivers/base/firmware_loader/fallback.c
index 358354148dec..b676a99c469c 100644
--- a/drivers/base/firmware_loader/fallback.c
+++ b/drivers/base/firmware_loader/fallback.c
@@ -125,7 +125,7 @@ static ssize_t timeout_show(struct class *class, struct class_attribute *attr,
 }
 
 /**
- * firmware_timeout_store - set number of seconds to wait for firmware
+ * firmware_timeout_store() - set number of seconds to wait for firmware
  * @class: device class pointer
  * @attr: device attribute pointer
  * @buf: buffer to scan for timeout value
@@ -239,7 +239,7 @@ static int map_fw_priv_pages(struct fw_priv *fw_priv)
 }
 
 /**
- * firmware_loading_store - set value in the 'loading' control file
+ * firmware_loading_store() - set value in the 'loading' control file
  * @dev: device pointer
  * @attr: device attribute pointer
  * @buf: buffer to scan for loading control value
@@ -431,7 +431,7 @@ static int fw_realloc_pages(struct fw_sysfs *fw_sysfs, int min_size)
 }
 
 /**
- * firmware_data_write - write method for firmware
+ * firmware_data_write() - write method for firmware
  * @filp: open sysfs file
  * @kobj: kobject for the device
  * @bin_attr: bin_attr structure
@@ -512,7 +512,7 @@ static const struct attribute_group *fw_dev_attr_groups[] = {
 
 static struct fw_sysfs *
 fw_create_instance(struct firmware *firmware, const char *fw_name,
-                   struct device *device, unsigned int opt_flags)
+                   struct device *device, enum fw_opt opt_flags)
 {
         struct fw_sysfs *fw_sysfs;
         struct device *f_dev;
@@ -537,7 +537,7 @@ exit:
 }
 
 /**
- * fw_load_sysfs_fallback - load a firmware via the sysfs fallback mechanism
+ * fw_load_sysfs_fallback() - load a firmware via the sysfs fallback mechanism
  * @fw_sysfs: firmware sysfs information for the firmware to load
  * @opt_flags: flags of options, FW_OPT_*
  * @timeout: timeout to wait for the load
@@ -545,7 +545,7 @@ exit:
  * In charge of constructing a sysfs fallback interface for firmware loading.
  **/
 static int fw_load_sysfs_fallback(struct fw_sysfs *fw_sysfs,
-                                  unsigned int opt_flags, long timeout)
+                                  enum fw_opt opt_flags, long timeout)
 {
         int retval = 0;
         struct device *f_dev = &fw_sysfs->dev;
@@ -599,7 +599,7 @@ err_put_dev:
 
 static int fw_load_from_user_helper(struct firmware *firmware,
                                     const char *name, struct device *device,
-                                    unsigned int opt_flags)
+                                    enum fw_opt opt_flags)
 {
         struct fw_sysfs *fw_sysfs;
         long timeout;
@@ -640,7 +640,7 @@ out_unlock:
         return ret;
 }
 
-static bool fw_force_sysfs_fallback(unsigned int opt_flags)
+static bool fw_force_sysfs_fallback(enum fw_opt opt_flags)
 {
         if (fw_fallback_config.force_sysfs_fallback)
                 return true;
@@ -649,7 +649,7 @@ static bool fw_force_sysfs_fallback(unsigned int opt_flags)
         return true;
 }
 
-static bool fw_run_sysfs_fallback(unsigned int opt_flags)
+static bool fw_run_sysfs_fallback(enum fw_opt opt_flags)
 {
         if (fw_fallback_config.ignore_sysfs_fallback) {
                 pr_info_once("Ignoring firmware sysfs fallback due to sysctl knob\n");
@@ -662,14 +662,39 @@ static bool fw_run_sysfs_fallback(unsigned int opt_flags)
         return fw_force_sysfs_fallback(opt_flags);
 }
 
-int fw_sysfs_fallback(struct firmware *fw, const char *name,
-                      struct device *device,
-                      unsigned int opt_flags,
-                      int ret)
+/**
+ * firmware_fallback_sysfs() - use the fallback mechanism to find firmware
+ * @fw: pointer to firmware image
+ * @name: name of firmware file to look for
+ * @device: device for which firmware is being loaded
+ * @opt_flags: options to control firmware loading behaviour
+ * @ret: return value from direct lookup which triggered the fallback mechanism
+ *
+ * This function is called if direct lookup for the firmware failed, it enables
+ * a fallback mechanism through userspace by exposing a sysfs loading
+ * interface. Userspace is in charge of loading the firmware through the syfs
+ * loading interface. This syfs fallback mechanism may be disabled completely
+ * on a system by setting the proc sysctl value ignore_sysfs_fallback to true.
+ * If this false we check if the internal API caller set the @FW_OPT_NOFALLBACK
+ * flag, if so it would also disable the fallback mechanism. A system may want
+ * to enfoce the sysfs fallback mechanism at all times, it can do this by
+ * setting ignore_sysfs_fallback to false and force_sysfs_fallback to true.
+ * Enabling force_sysfs_fallback is functionally equivalent to build a kernel
+ * with CONFIG_FW_LOADER_USER_HELPER_FALLBACK.
+ **/
+int firmware_fallback_sysfs(struct firmware *fw, const char *name,
+                            struct device *device,
+                            enum fw_opt opt_flags,
+                            int ret)
 {
         if (!fw_run_sysfs_fallback(opt_flags))
                 return ret;
 
-        dev_warn(device, "Falling back to user helper\n");
+        if (!(opt_flags & FW_OPT_NO_WARN))
+                dev_warn(device, "Falling back to syfs fallback for: %s\n",
+                                 name);
+        else
+                dev_dbg(device, "Falling back to sysfs fallback for: %s\n",
+                                name);
         return fw_load_from_user_helper(fw, name, device, opt_flags);
 }