[Midnightbsd-cvs] src [8177] trunk/share/man/man9/bus_dma.9: clarify the bus dma does not stall future load requests once a load is deferred.

[laffer1 at midnightbsd.org]

Revision: 8177
          http://svnweb.midnightbsd.org/src/?rev=8177
Author:   laffer1
Date:     2016-09-16 22:47:46 -0400 (Fri, 16 Sep 2016)
Log Message:
-----------
clarify the bus dma does not stall future load requests once a load is deferred.

Modified Paths:
--------------
    trunk/share/man/man9/bus_dma.9

Modified: trunk/share/man/man9/bus_dma.9
===================================================================
--- trunk/share/man/man9/bus_dma.9	2016-09-17 02:46:45 UTC (rev 8176)
+++ trunk/share/man/man9/bus_dma.9	2016-09-17 02:47:46 UTC (rev 8177)
@@ -580,8 +580,13 @@
 The mapping has been deferred for lack of resources.
 The callback will be called as soon as resources are available.
 Callbacks are serviced in FIFO order.
-To ensure that ordering is guaranteed, all subsequent load requests will also
-be deferred until all callbacks have been processed.
+.Pp
+Note that subsequent load operations for the same tag that do not require
+extra resources will still succeed.
+This may result in out-of-order processing of requests.
+If the caller requires the order of requests to be preserved,
+then the caller is required to stall subsequent requests until a pending
+request's callback is invoked.
 .It Er ENOMEM
 The load request has failed due to insufficient resources, and the caller
 specifically used the