From 3acebd3e8140619f5093b8a70d1d9affcc634cab 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 05827eccc53a..ce5a9f2584f3 100644 --- a/drivers/hv/connection.c +++ b/drivers/hv/connection.c @@ -319,9 +319,13 @@ 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);