From: Stephen Hemminger <step...@networkplumber.org>
Don't signal host if it has disabled interrupts for that
ring buffer. Check the feature bit to see if host supports
pending send size flag.
Signed-off-by: Stephen Hemminger <sthem...@microsoft.com>
Signed-off-by: K. Y. Srinivasan <k...@microsoft.com>
---
drivers/hv/ring_buffer.c | 27 +++++++++++++++++++--------
1 files changed, 19 insertions(+), 8 deletions(-)
diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c
index b0f7952..741daa6 100644
--- a/drivers/hv/ring_buffer.c
+++ b/drivers/hv/ring_buffer.c
@@ -396,7 +396,6 @@ void hv_pkt_iter_close(struct vmbus_channel *channel)
{
struct hv_ring_buffer_info *rbi = &channel->inbound;
u32 orig_write_sz = hv_get_bytes_to_write(rbi);
- u32 pending_sz;
/*
* Make sure all reads are done before we update the read index since
@@ -419,15 +418,27 @@ void hv_pkt_iter_close(struct vmbus_channel *channel)
*/
virt_mb();
- pending_sz = READ_ONCE(rbi->ring_buffer->pending_send_sz);
- /* If the other end is not blocked on write don't bother. */
- if (pending_sz == 0)
+ /* If host has disabled notifications then skip */
+ if (rbi->ring_buffer->interrupt_mask)
return;
- if (hv_get_bytes_to_write(rbi) < pending_sz)
- return;
+ if (rbi->ring_buffer->feature_bits.feat_pending_send_sz) {
+ u32 pending_sz = READ_ONCE(rbi->ring_buffer->pending_send_sz);
- if (orig_write_sz < pending_sz)
- vmbus_setevent(channel);
+ /*
+ * If there was space before we began iteration,
+ * then host was not blocked. Also handles case where
+ * pending_sz is zero then host has nothing pending
+ * and does not need to be signaled.
+ */
+ if (orig_write_sz > pending_sz)
+ return;
+
+ /* If pending write will not fit, don't give false hope. */
+ if (hv_get_bytes_to_write(rbi) < pending_sz)
+ return;
+ }
+
+ vmbus_setevent(channel);
}
EXPORT_SYMBOL_GPL(hv_pkt_iter_close);
--
1.7.1
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