linux 2.6.16.38 w/ vs2.0.3-rc1

[linux-2.6.git] / Documentation / firmware_class / README

diff --git a/Documentation/firmware_class/README b/Documentation/firmware_class/README
index e9cc8bb..43e836c 100644 (file)
--- a/Documentation/firmware_class/README
+++ b/Documentation/firmware_class/README
@@ -105,3 +105,20 @@
    on the setup, so I think that the choice on what firmware to make
    persistent should be left to userspace.
 
+ - Why register_firmware()+__init can be useful:
+       - For boot devices needing firmware.
+       - To make the transition easier:
+               The firmware can be declared __init and register_firmware()
+               called on module_init. Then the firmware is warranted to be
+               there even if "firmware hotplug userspace" is not there yet or
+               it doesn't yet provide the needed firmware.
+               Once the firmware is widely available in userspace, it can be
+               removed from the kernel. Or made optional (CONFIG_.*_FIRMWARE).
+
+       In either case, if firmware hotplug support is there, it can move the
+       firmware out of kernel memory into the real filesystem for later
+       usage.
+
+       Note: If persistence is implemented on top of initramfs,
+       register_firmware() may not be appropriate.
+