diff options
| author | Jason Wang <jasowang@redhat.com> | 2013-06-20 12:58:57 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-06-24 16:24:17 -0700 |
| commit | e91e84fa4cfeb67a9a096f1adaa1a1a692474724 (patch) | |
| tree | 7e36ab11890da81a89817e2b24e85cc11b480b83 /drivers/hv/ring_buffer.c | |
| parent | 0686ab7a7d05cda3373e311a49b2478bd4f03c5d (diff) | |
| download | lwn-e91e84fa4cfeb67a9a096f1adaa1a1a692474724.tar.gz lwn-e91e84fa4cfeb67a9a096f1adaa1a1a692474724.zip | |
drivers: hv: check interrupt mask before read_index
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@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hv/ring_buffer.c')
| -rw-r--r-- | 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 791f45dfc85d..26c93cf9f6be 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. |