xen/evtchn_fifo: fix error return code in evtchn_fifo_setup()

Fix to return -ENOMEM from the error handling case instead of
0 (overwrited to 0 by the HYPERVISOR_event_channel_op call),
otherwise the error condition cann't be reflected from the
return value.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>

1 files changed, 4 insertions, 2 deletions

diff --git a/drivers/xen/events/events_fifo.c b/drivers/xen/events/events_fifo.c
index e2bf9571f7fe..5b2c039f16c5 100644
--- a/drivers/xen/events/events_fifo.c
+++ b/drivers/xen/events/events_fifo.c
@@ -109,7 +109,7 @@ static int evtchn_fifo_setup(struct irq_info *info)
 {
         unsigned port = info->evtchn;
         unsigned new_array_pages;
-        int ret = -ENOMEM;
+        int ret;
 
         new_array_pages = port / EVENT_WORDS_PER_PAGE + 1;
 
@@ -124,8 +124,10 @@ static int evtchn_fifo_setup(struct irq_info *info)
                 array_page = event_array[event_array_pages];
                 if (!array_page) {
                         array_page = (void *)__get_free_page(GFP_KERNEL);
-                        if (array_page == NULL)
+                        if (array_page == NULL) {
+                                ret = -ENOMEM;
                                 goto error;
+                        }
                         event_array[event_array_pages] = array_page;
                 }