[PATCH v9 04/17] vdpa: Fail the vdpa_reset() if fail to set device status to zero

[Xie Yongji]

Re-read the device status to ensure it's set to zero during
resetting. Otherwise, fail the vdpa_reset() after timeout.

Signed-off-by: Xie Yongji <xieyongji@xxxxxxxxxxxxx>
---
 include/linux/vdpa.h | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
index f822490db584..198c30e84b5d 100644
--- a/include/linux/vdpa.h
+++ b/include/linux/vdpa.h
@@ -6,6 +6,7 @@
 #include <linux/device.h>
 #include <linux/interrupt.h>
 #include <linux/vhost_iotlb.h>
+#include <linux/delay.h>
 
 /**
  * struct vdpa_calllback - vDPA callback definition.
@@ -340,12 +341,24 @@ static inline struct device *vdpa_get_dma_dev(struct vdpa_device *vdev)
 	return vdev->dma_dev;
 }
 
-static inline void vdpa_reset(struct vdpa_device *vdev)
+#define VDPA_RESET_TIMEOUT_MS 1000
+
+static inline int vdpa_reset(struct vdpa_device *vdev)
 {
 	const struct vdpa_config_ops *ops = vdev->config;
+	int timeout = 0;
 
 	vdev->features_valid = false;
 	ops->set_status(vdev, 0);
+	while (ops->get_status(vdev)) {
+		timeout += 20;
+		if (timeout > VDPA_RESET_TIMEOUT_MS)
+			return -EIO;
+
+		msleep(20);
+	}
+
+	return 0;
 }
 
 static inline int vdpa_set_features(struct vdpa_device *vdev, u64 features)
-- 
2.11.0