[dpdk-dev] [PATCH] net/virtio: wait device ready in device reset

From: Xueming Li <xuemingl@nvidia.com>
Cc: <dev@dpdk.org>, <xuemingl@nvidia.com>,
	Maxime Coquelin <maxime.coquelin@redhat.com>,
	Chenbo Xia <chenbo.xia@intel.com>
Subject: [dpdk-dev] [PATCH] net/virtio: wait device ready in device reset
Date: Mon, 23 Aug 2021 09:39:06 +0300	[thread overview]
Message-ID: <20210823063906.1382544-1-xuemingl@nvidia.com> (raw)

According to virtio spec, the device MUST reset when 0 is written to
device_status, and present a 0 in device_status once that is done.

This patch adds the missing part of waiting status 0 in reset function.

Signed-off-by: Xueming Li <xuemingl@nvidia.com>
---
 drivers/net/virtio/virtio.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/net/virtio/virtio.c b/drivers/net/virtio/virtio.c
index 7e1e77797f..f003f612d6 100644
--- a/drivers/net/virtio/virtio.c
+++ b/drivers/net/virtio/virtio.c
@@ -3,6 +3,8 @@
  * Copyright(c) 2020 Red Hat, Inc.
  */
 
+#include <unistd.h>
+
 #include "virtio.h"
 
 uint64_t
@@ -39,8 +41,9 @@ void
 virtio_reset(struct virtio_hw *hw)
 {
 	VIRTIO_OPS(hw)->set_status(hw, VIRTIO_CONFIG_STATUS_RESET);
-	/* flush status write */
-	VIRTIO_OPS(hw)->get_status(hw);
+	/* Flush status write and wait device ready. */
+	while (VIRTIO_OPS(hw)->get_status(hw) != VIRTIO_CONFIG_STATUS_RESET)
+		usleep(1000L);
 }
 
 void
-- 
2.25.1

