Handle the case when the write to the ringbuffer fails. In this case,
unconditionally signal the host. Since we may have deferred signalling
the host based on the kick_q parameter, signalling the host
unconditionally in this case deals with the issue.
Signed-off-by: K. Y. Srinivasan <k...@microsoft.com>
---
drivers/hv/channel.c | 28 ++++++++++++++++++++++++++--
1 files changed, 26 insertions(+), 2 deletions(-)
diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index fddd3b5..54da66d 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -611,7 +611,19 @@ int vmbus_sendpacket_ctl(struct vmbus_channel *channel,
void *buffer,
ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
- if ((ret == 0) && kick_q && signal)
+ /*
+ * Signalling the host is conditional on many factors:
+ * 1. The ring state changed from being empty to non-empty.
+ * This is tracked by the variable "signal".
+ * 2. The variable kick_q tracks if more data will be placed
+ * on the ring. We will not signal if more data is
+ * to be placed.
+ *
+ * If we cannot write to the ring-buffer; signal the host
+ * even if we may not have written anything. This is a rare
+ * enough condition that it should not matter.
+ */
+ if (((ret == 0) && kick_q && signal) || (ret))
vmbus_setevent(channel);
return ret;
@@ -702,7 +714,19 @@ int vmbus_sendpacket_pagebuffer_ctl(struct vmbus_channel
*channel,
ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
- if ((ret == 0) && kick_q && signal)
+ /*
+ * Signalling the host is conditional on many factors:
+ * 1. The ring state changed from being empty to non-empty.
+ * This is tracked by the variable "signal".
+ * 2. The variable kick_q tracks if more data will be placed
+ * on the ring. We will not signal if more data is
+ * to be placed.
+ *
+ * If we cannot write to the ring-buffer; signal the host
+ * even if we may not have written anything. This is a rare
+ * enough condition that it should not matter.
+ */
+ if (((ret == 0) && kick_q && signal) || (ret))
vmbus_setevent(channel);
return ret;
--
1.7.4.1
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