Force the firmware sysfs fallback mechanism when possible

configname: CONFIG_FW_LOADER_USER_HELPER_FALLBACK

Linux Kernel Configuration
└─>Device Drivers
└─>Generic Driver Options
└─>Firmware loader
└─>Force the firmware sysfs fallback mechanism when possible
In linux kernel since version 3.17 (release Date: 2014-10-05)  
Enabling this option forces a sysfs userspace fallback mechanism
to be used for all firmware requests which explicitly do not disable a
a fallback mechanism. Firmware calls which do prohibit a fallback
mechanism is request_firmware_direct(). This option is kept for
backward compatibility purposes given this precise mechanism can also
be enabled by setting the proc sysctl value to true:

/proc/sys/kernel/firmware_config/force_sysfs_fallback

If you are unsure about this, say N here.