Drivers: hv: vmbus: Fix a bug in the channel callback dispatch code

Starting with Win8, we have implemented several optimizations to improve the scalability and performance of the VMBUS transport between the Host and the Guest. Some of the non-performance critical services cannot leverage these optimization since they only read and process one message at a time. Make adjustments to the callback dispatch code to account for the way non-performance critical drivers handle reading of the channel. Signed-off-by: K. Y. Srinivasan <[email protected]> Cc: <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
Baughn · Jul 9, 2014 · affb1af · affb1af
1 parent a497c3b
commit affb1af
Showing 1 changed file with 6 additions and 2 deletions.
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
@@ -339,9 +339,13 @@ static void process_chn_event(u32 relid)
 		 */
 
 		do {
-			hv_begin_read(&channel->inbound);
+			if (read_state)
+				hv_begin_read(&channel->inbound);
 			channel->onchannel_callback(arg);
-			bytes_to_read = hv_end_read(&channel->inbound);
+			if (read_state)
+				bytes_to_read = hv_end_read(&channel->inbound);
+			else
+				bytes_to_read = 0;
 		} while (read_state && (bytes_to_read != 0));
 	} else {
 		pr_err("no channel callback for relid - %u\n", relid);