[PATCH] dell_rbu: enhancements and fixes

BUG fixes:

  The driver used to allocate memory with spinlock held which has been
  fixed in this patch.

  The driver was printing the entire buffer when it received a invalid
  entry in image_type.  The fix is to only print a warning message and not
  the buffer.

Usability enhancements:

  It is possible that due to user error the /sys/class/firmware/dell_rbu
  entries might be missing, this can happen if the user does the following

	echo 1 > /sys/class/firmware/dell_rbu/loading
	echo 0 > /sys/class/firmware/dell_rbu/loading

  This will make the entries in /sys/class/firmware/ to disappear and the
  only way get them back was bby unloading and loading the driver.

  This patch makes the user recreate these entries by echoing init in to
  image_type.

This patch has been tested with Libsmbios and Dell OpenManage.

Signed-off-by: Abhay Salunke <Abhay_Salunke@dell.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/Documentation/dell_rbu.txt b/Documentation/dell_rbu.txt
index bcfa5c3..95d7f62 100644
--- a/Documentation/dell_rbu.txt
+++ b/Documentation/dell_rbu.txt
@@ -13,6 +13,8 @@
 and notebooks (starting from those sold in 2005).
 Please go to  http://support.dell.com register and you can find info on
 OpenManage and Dell Update packages (DUP).
+Libsmbios can also be used to update BIOS on Dell systems go to
+http://linux.dell.com/libsmbios/ for details.
 
 Dell_RBU driver supports BIOS update using the monilothic image and packetized
 image methods. In case of moniolithic the driver allocates a contiguous chunk
@@ -22,8 +24,8 @@
 maintains a link list of packets for reading them back.
 If the dell_rbu driver is unloaded all the allocated memory is freed.
 
-The rbu driver needs to have an application which will inform the BIOS to
-enable the update in the next system reboot.
+The rbu driver needs to have an application (as mentioned above)which will
+inform the BIOS to enable the update in the next system reboot.
 
 The user should not unload the rbu driver after downloading the BIOS image
 or updating.
@@ -42,9 +44,11 @@
 of contiguous memory and the BIOS image is scattered in these packets.
 
 By default the driver uses monolithic memory for the update type. This can be
-changed to contiguous during the driver load time by specifying the load
+changed to packets during the driver load time by specifying the load
 parameter image_type=packet.  This can also be changed later as below
 echo packet > /sys/devices/platform/dell_rbu/image_type
+Also echoing either mono ,packet or init in to image_type will free up the
+memory allocated by the driver.
 
 Do the steps below to download the BIOS image.
 1) echo 1 > /sys/class/firmware/dell_rbu/loading
@@ -53,9 +57,13 @@
 
 The /sys/class/firmware/dell_rbu/ entries will remain till the following is
 done.
-echo -1 > /sys/class/firmware/dell_rbu/loading
-
+echo -1 > /sys/class/firmware/dell_rbu/loading.
 Until this step is completed the drivr cannot be unloaded.
+If an user by accident executes steps 1 and 3 above without executing step 2;
+it will make the /sys/class/firmware/dell_rbu/ entries to disappear.
+The entries can be recreated by doing the following
+echo init > /sys/devices/platform/dell_rbu/image_type
+NOTE: echoing init in image_type does not change it original value.
 
 Also the driver provides /sys/devices/platform/dell_rbu/data readonly file to
 read back the image downloaded. This is useful in case of packet update