[PATCH] update max_sectors documentation
The max_sectors has been split into max_hw_sectors and max_sectors for some
time. A patch to have blk_queue_max_sectors enforce this was sent by
me and it broke IDE. This patch updates the documentation.
Signed-off-by: Jens Axboe <axboe@suse.de>
diff --git a/Documentation/block/biodoc.txt b/Documentation/block/biodoc.txt
index 8e63831..f989a9e 100644
--- a/Documentation/block/biodoc.txt
+++ b/Documentation/block/biodoc.txt
@@ -132,8 +132,18 @@
limit. No highmem default.
blk_queue_max_sectors(q, max_sectors)
- Maximum size request you can handle in units of 512 byte
- sectors. 255 default.
+ Sets two variables that limit the size of the request.
+
+ - The request queue's max_sectors, which is a soft size in
+ in units of 512 byte sectors, and could be dynamically varied
+ by the core kernel.
+
+ - The request queue's max_hw_sectors, which is a hard limit
+ and reflects the maximum size request a driver can handle
+ in units of 512 byte sectors.
+
+ The default for both max_sectors and max_hw_sectors is
+ 255. The upper limit of max_sectors is 1024.
blk_queue_max_phys_segments(q, max_segments)
Maximum physical segments you can handle in a request. 128