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authorK. Y. Srinivasan <kys@microsoft.com>2011-08-25 18:49:01 +0200
committerGreg Kroah-Hartman <gregkh@suse.de>2011-08-26 00:23:19 +0200
commit5289d3d160e8d5c63974502696ab5def71891f18 (patch)
treee420b755b62608b543cd5fa897a9bd5b1186bef4
parentStaging: hv: netvsc: Get rid of an unnecessary print statement in netvsc_probe() (diff)
downloadlinux-5289d3d160e8d5c63974502696ab5def71891f18.tar.xz
linux-5289d3d160e8d5c63974502696ab5def71891f18.zip
Staging: hv: vmbus: Retry vmbus_post_msg() before giving up
The function hv_post_msg() can fail because of transient resource conditions. It may be useful to retry the operation. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--arch/x86/include/asm/hyperv.h1
-rw-r--r--drivers/staging/hv/connection.c18
2 files changed, 18 insertions, 1 deletions
diff --git a/arch/x86/include/asm/hyperv.h b/arch/x86/include/asm/hyperv.h
index 5df477ac3af7..b80420bcd09d 100644
--- a/arch/x86/include/asm/hyperv.h
+++ b/arch/x86/include/asm/hyperv.h
@@ -189,5 +189,6 @@
#define HV_STATUS_INVALID_HYPERCALL_CODE 2
#define HV_STATUS_INVALID_HYPERCALL_INPUT 3
#define HV_STATUS_INVALID_ALIGNMENT 4
+#define HV_STATUS_INSUFFICIENT_BUFFERS 19
#endif
diff --git a/drivers/staging/hv/connection.c b/drivers/staging/hv/connection.c
index 0e7efce31282..a88ad7072566 100644
--- a/drivers/staging/hv/connection.c
+++ b/drivers/staging/hv/connection.c
@@ -25,6 +25,7 @@
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/wait.h>
+#include <linux/delay.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
@@ -268,10 +269,25 @@ void vmbus_on_event(unsigned long data)
int vmbus_post_msg(void *buffer, size_t buflen)
{
union hv_connection_id conn_id;
+ int ret = 0;
+ int retries = 0;
conn_id.asu32 = 0;
conn_id.u.id = VMBUS_MESSAGE_CONNECTION_ID;
- return hv_post_message(conn_id, 1, buffer, buflen);
+
+ /*
+ * hv_post_message() can have transient failures because of
+ * insufficient resources. Retry the operation a couple of
+ * times before giving up.
+ */
+ while (retries < 3) {
+ ret = hv_post_message(conn_id, 1, buffer, buflen);
+ if (ret != HV_STATUS_INSUFFICIENT_BUFFERS)
+ return ret;
+ retries++;
+ msleep(100);
+ }
+ return ret;
}
/*