From: K. Y. Srinivasan Date: Mon, 7 Jul 2014 23:34:24 +0000 (-0700) Subject: Drivers: hv: vmbus: Fix a bug in the channel callback dispatch code X-Git-Tag: firefly_0821_release~176^2~3628^2~2 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=affb1aff300ddee54df307812b38f166e8a865ef;p=firefly-linux-kernel-4.4.55.git 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 Cc: Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c index e84f4526eb36..ae22e3c1fc4c 100644 --- 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);