diff options
| -rw-r--r-- | 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 fddd3b5e59a9..54da66dc7d16 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; |