4 files changed, 80 insertions, 4 deletions

diff --git a/drivers/net/enic/enic_main.c b/drivers/net/enic/enic_main.c
index 2821a1db547d..58cae6e6a59c 100644
--- a/drivers/net/enic/enic_main.c
+++ b/drivers/net/enic/enic_main.c
@@ -851,6 +851,50 @@ static int enic_rq_alloc_buf(struct vnic_rq *rq)
 	return 0;
 }
 
+static int enic_rq_alloc_buf_a1(struct vnic_rq *rq)
+{
+	struct rq_enet_desc *desc = vnic_rq_next_desc(rq);
+
+	if (vnic_rq_posting_soon(rq)) {
+
+		/* SW workaround for A0 HW erratum: if we're just about
+		 * to write posted_index, insert a dummy desc
+		 * of type resvd
+		 */
+
+		rq_enet_desc_enc(desc, 0, RQ_ENET_TYPE_RESV2, 0);
+		vnic_rq_post(rq, 0, 0, 0, 0);
+	} else {
+		return enic_rq_alloc_buf(rq);
+	}
+
+	return 0;
+}
+
+static int enic_set_rq_alloc_buf(struct enic *enic)
+{
+	enum vnic_dev_hw_version hw_ver;
+	int err;
+
+	err = vnic_dev_hw_version(enic->vdev, &hw_ver);
+	if (err)
+		return err;
+
+	switch (hw_ver) {
+	case VNIC_DEV_HW_VER_A1:
+		enic->rq_alloc_buf = enic_rq_alloc_buf_a1;
+		break;
+	case VNIC_DEV_HW_VER_A2:
+	case VNIC_DEV_HW_VER_UNKNOWN:
+		enic->rq_alloc_buf = enic_rq_alloc_buf;
+		break;
+	default:
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
 static int enic_get_skb_header(struct sk_buff *skb, void **iphdr,
 	void **tcph, u64 *hdr_flags, void *priv)
 {
@@ -1058,7 +1102,7 @@ static int enic_poll(struct napi_struct *napi, int budget)
 		/* Replenish RQ
 		 */
 
-		vnic_rq_fill(&enic->rq[0], enic_rq_alloc_buf);
+		vnic_rq_fill(&enic->rq[0], enic->rq_alloc_buf);
 
 	} else {
 
@@ -1093,7 +1137,7 @@ static int enic_poll_msix(struct napi_struct *napi, int budget)
 		/* Replenish RQ
 		 */
 
-		vnic_rq_fill(&enic->rq[0], enic_rq_alloc_buf);
+		vnic_rq_fill(&enic->rq[0], enic->rq_alloc_buf);
 
 		/* Return intr event credits for this polling
 		 * cycle.  An intr event is the completion of a
@@ -1269,7 +1313,7 @@ static int enic_open(struct net_device *netdev)
 	}
 
 	for (i = 0; i < enic->rq_count; i++) {
-		err = vnic_rq_fill(&enic->rq[i], enic_rq_alloc_buf);
+		err = vnic_rq_fill(&enic->rq[i], enic->rq_alloc_buf);
 		if (err) {
 			printk(KERN_ERR PFX
 				"%s: Unable to alloc receive buffers.\n",
diff --git a/drivers/net/enic/vnic_dev.c b/drivers/net/enic/vnic_dev.c
index d5c28efedd98..c8d3fc7517b0 100644
--- a/drivers/net/enic/vnic_dev.c
+++ b/drivers/net/enic/vnic_dev.c
@@ -349,6 +349,25 @@ int vnic_dev_fw_info(struct vnic_dev *vdev,
 	return err;
 }
 
+int vnic_dev_hw_version(struct vnic_dev *vdev, enum vnic_dev_hw_version *hw_ver)
+{
+	struct vnic_devcmd_fw_info *fw_info;
+	int err;
+
+	err = vnic_dev_fw_info(vdev, &fw_info);
+	if (err)
+		return err;
+
+	if (strncmp(fw_info->hw_version, "A1", sizeof("A1")) == 0)
+		*hw_ver = VNIC_DEV_HW_VER_A1;
+	else if (strncmp(fw_info->hw_version, "A2", sizeof("A2")) == 0)
+		*hw_ver = VNIC_DEV_HW_VER_A2;
+	else
+		*hw_ver = VNIC_DEV_HW_VER_UNKNOWN;
+
+	return 0;
+}
+
 int vnic_dev_spec(struct vnic_dev *vdev, unsigned int offset, unsigned int size,
 	void *value)
 {
diff --git a/drivers/net/enic/vnic_dev.h b/drivers/net/enic/vnic_dev.h
index d960edb8cdf5..db1d63e0b97c 100644
--- a/drivers/net/enic/vnic_dev.h
+++ b/drivers/net/enic/vnic_dev.h
@@ -41,6 +41,12 @@ static inline void writeq(u64 val, void __iomem *reg)
 }
 #endif
 
+enum vnic_dev_hw_version {
+	VNIC_DEV_HW_VER_UNKNOWN,
+	VNIC_DEV_HW_VER_A1,
+	VNIC_DEV_HW_VER_A2,
+};
+
 enum vnic_dev_intr_mode {
 	VNIC_DEV_INTR_MODE_UNKNOWN,
 	VNIC_DEV_INTR_MODE_INTX,
@@ -88,6 +94,8 @@ int vnic_dev_cmd(struct vnic_dev *vdev, enum vnic_devcmd_cmd cmd,
 	u64 *a0, u64 *a1, int wait);
 int vnic_dev_fw_info(struct vnic_dev *vdev,
 	struct vnic_devcmd_fw_info **fw_info);
+int vnic_dev_hw_version(struct vnic_dev *vdev,
+	enum vnic_dev_hw_version *hw_ver);
 int vnic_dev_spec(struct vnic_dev *vdev, unsigned int offset, unsigned int size,
 	void *value);
 int vnic_dev_stats_clear(struct vnic_dev *vdev);
diff --git a/drivers/net/enic/vnic_rq.h b/drivers/net/enic/vnic_rq.h
index fd0ef66d2e9f..f7b5730cb744 100644
--- a/drivers/net/enic/vnic_rq.h
+++ b/drivers/net/enic/vnic_rq.h
@@ -143,6 +143,11 @@ static inline void vnic_rq_post(struct vnic_rq *rq,
 	}
 }
 
+static inline int vnic_rq_posting_soon(struct vnic_rq *rq)
+{
+	return ((rq->to_use->index & VNIC_RQ_RETURN_RATE) == 0);
+}
+
 static inline void vnic_rq_return_descs(struct vnic_rq *rq, unsigned int count)
 {
 	rq->ring.desc_avail += count;
@@ -186,7 +191,7 @@ static inline int vnic_rq_fill(struct vnic_rq *rq,
 {
 	int err;
 
-	while (vnic_rq_desc_avail(rq) > 1) {
+	while (vnic_rq_desc_avail(rq) > 0) {
 
 		err = (*buf_fill)(rq);
 		if (err)