From 17256c6385fd3a5e000a9d2e9b89eb09f70b46e6 Mon Sep 17 00:00:00 2001 From: "K. Y. Srinivasan" Date: Mon, 7 Jul 2014 16:34:24 -0700 Subject: [PATCH] Drivers: hv: vmbus: Fix a bug in the channel callback dispatch code commit affb1aff300ddee54df307812b38f166e8a865ef upstream. 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 Signed-off-by: Greg Kroah-Hartman --- drivers/hv/connection.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c index fd02cb7..b9f5d29 100644 --- a/drivers/hv/connection.c +++ b/drivers/hv/connection.c @@ -304,9 +304,13 @@ 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); -- 2.7.4