From 5289d3d160e8d5c63974502696ab5def71891f18 Mon Sep 17 00:00:00 2001 From: "K. Y. Srinivasan" Date: Thu, 25 Aug 2011 09:49:01 -0700 Subject: [PATCH] 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 Signed-off-by: Haiyang Zhang Signed-off-by: Greg Kroah-Hartman --- arch/x86/include/asm/hyperv.h | 1 + drivers/staging/hv/connection.c | 18 +++++++++++++++++- 2 files changed, 18 insertions(+), 1 deletion(-) 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 #include #include +#include #include #include #include @@ -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; } /* -- 2.20.1