This patches add a read barriers to force the driver to check the interrupt mask before read_index. Otherwise we may lost a kick to host. Cc: K. Y. Srinivasan <kys@xxxxxxxxxxxxx> Cc: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx> Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx> --- drivers/hv/ring_buffer.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c index 791f45d..26c93cf 100644 --- a/drivers/hv/ring_buffer.c +++ b/drivers/hv/ring_buffer.c @@ -75,6 +75,8 @@ static bool hv_need_to_signal(u32 old_write, struct hv_ring_buffer_info *rbi) if (rbi->ring_buffer->interrupt_mask) return false; + /* check interrupt_mask before read_index */ + rmb(); /* * This is the only case we need to signal when the * ring transitions from being empty to non-empty. -- 1.7.1 _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
