Merge branch 'dpaa2-eth-misc-cleanup'

Ioana Ciornei says:

====================
dpaa2-eth: misc cleanup

This patch set consists of some cleanup patches ranging from removing dead
code to fixing a minor issue in ethtool stats. Also, unbounded while loops
are removed from the driver by adding a maximum number of retries for DPIO
portal commands.

Changes in v2:
 - return -ETIMEDOUT where possible if the number of retries is hit
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 35 insertions, 14 deletions

diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
index 162d7d8fb2950c..1b959d7ec923e1 100644
--- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
+++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
@@ -221,6 +221,7 @@ static void xdp_release_buf(struct dpaa2_eth_priv *priv,
 			    struct dpaa2_eth_channel *ch,
 			    dma_addr_t addr)
 {
+	int retries = 0;
 	int err;
 
 	ch->xdp.drop_bufs[ch->xdp.drop_cnt++] = addr;
@@ -229,8 +230,11 @@ static void xdp_release_buf(struct dpaa2_eth_priv *priv,
 
 	while ((err = dpaa2_io_service_release(ch->dpio, priv->bpid,
 					       ch->xdp.drop_bufs,
-					       ch->xdp.drop_cnt)) == -EBUSY)
+					       ch->xdp.drop_cnt)) == -EBUSY) {
+		if (retries++ >= DPAA2_ETH_SWP_BUSY_RETRIES)
+			break;
 		cpu_relax();
+	}
 
 	if (err) {
 		free_bufs(priv, ch->xdp.drop_bufs, ch->xdp.drop_cnt);
@@ -458,7 +462,7 @@ static int consume_frames(struct dpaa2_eth_channel *ch,
 	struct dpaa2_eth_fq *fq = NULL;
 	struct dpaa2_dq *dq;
 	const struct dpaa2_fd *fd;
-	int cleaned = 0;
+	int cleaned = 0, retries = 0;
 	int is_last;
 
 	do {
@@ -469,6 +473,11 @@ static int consume_frames(struct dpaa2_eth_channel *ch,
 			 * the store until we get some sort of valid response
 			 * token (either a valid frame or an "empty dequeue")
 			 */
+			if (retries++ >= DPAA2_ETH_SWP_BUSY_RETRIES) {
+				netdev_err_once(priv->net_dev,
+						"Unable to read a valid dequeue response\n");
+				return -ETIMEDOUT;
+			}
 			continue;
 		}
 
@@ -477,6 +486,7 @@ static int consume_frames(struct dpaa2_eth_channel *ch,
 
 		fq->consume(priv, ch, fd, fq);
 		cleaned++;
+		retries = 0;
 	} while (!is_last);
 
 	if (!cleaned)
@@ -949,6 +959,7 @@ static int add_bufs(struct dpaa2_eth_priv *priv,
 	u64 buf_array[DPAA2_ETH_BUFS_PER_CMD];
 	struct page *page;
 	dma_addr_t addr;
+	int retries = 0;
 	int i, err;
 
 	for (i = 0; i < DPAA2_ETH_BUFS_PER_CMD; i++) {
@@ -980,8 +991,11 @@ static int add_bufs(struct dpaa2_eth_priv *priv,
 release_bufs:
 	/* In case the portal is busy, retry until successful */
 	while ((err = dpaa2_io_service_release(ch->dpio, bpid,
-					       buf_array, i)) == -EBUSY)
+					       buf_array, i)) == -EBUSY) {
+		if (retries++ >= DPAA2_ETH_SWP_BUSY_RETRIES)
+			break;
 		cpu_relax();
+	}
 
 	/* If release command failed, clean up and bail out;
 	 * not much else we can do about it
@@ -1032,16 +1046,21 @@ static int seed_pool(struct dpaa2_eth_priv *priv, u16 bpid)
 static void drain_bufs(struct dpaa2_eth_priv *priv, int count)
 {
 	u64 buf_array[DPAA2_ETH_BUFS_PER_CMD];
+	int retries = 0;
 	int ret;
 
 	do {
 		ret = dpaa2_io_service_acquire(NULL, priv->bpid,
 					       buf_array, count);
 		if (ret < 0) {
+			if (ret == -EBUSY &&
+			    retries++ >= DPAA2_ETH_SWP_BUSY_RETRIES)
+				continue;
 			netdev_err(priv->net_dev, "dpaa2_io_service_acquire() failed\n");
 			return;
 		}
 		free_bufs(priv, buf_array, ret);
+		retries = 0;
 	} while (ret);
 }
 
@@ -1094,7 +1113,7 @@ static int pull_channel(struct dpaa2_eth_channel *ch)
 						    ch->store);
 		dequeues++;
 		cpu_relax();
-	} while (err == -EBUSY);
+	} while (err == -EBUSY && dequeues < DPAA2_ETH_SWP_BUSY_RETRIES);
 
 	ch->stats.dequeue_portal_busy += dequeues;
 	if (unlikely(err))
@@ -1118,6 +1137,7 @@ static int dpaa2_eth_poll(struct napi_struct *napi, int budget)
 	struct netdev_queue *nq;
 	int store_cleaned, work_done;
 	struct list_head rx_list;
+	int retries = 0;
 	int err;
 
 	ch = container_of(napi, struct dpaa2_eth_channel, napi);
@@ -1136,7 +1156,7 @@ static int dpaa2_eth_poll(struct napi_struct *napi, int budget)
 		refill_pool(priv, ch, priv->bpid);
 
 		store_cleaned = consume_frames(ch, &fq);
-		if (!store_cleaned)
+		if (store_cleaned <= 0)
 			break;
 		if (fq->type == DPAA2_RX_FQ) {
 			rx_cleaned += store_cleaned;
@@ -1163,7 +1183,7 @@ static int dpaa2_eth_poll(struct napi_struct *napi, int budget)
 	do {
 		err = dpaa2_io_service_rearm(ch->dpio, &ch->nctx);
 		cpu_relax();
-	} while (err == -EBUSY);
+	} while (err == -EBUSY && retries++ < DPAA2_ETH_SWP_BUSY_RETRIES);
 	WARN_ONCE(err, "CDAN notifications rearm failed on core %d",
 		  ch->nctx.desired_cpu);
 
@@ -2043,7 +2063,6 @@ static struct fsl_mc_device *setup_dpcon(struct dpaa2_eth_priv *priv)
 {
 	struct fsl_mc_device *dpcon;
 	struct device *dev = priv->net_dev->dev.parent;
-	struct dpcon_attr attrs;
 	int err;
 
 	err = fsl_mc_object_allocate(to_fsl_mc_device(dev),
@@ -2068,12 +2087,6 @@ static struct fsl_mc_device *setup_dpcon(struct dpaa2_eth_priv *priv)
 		goto close;
 	}
 
-	err = dpcon_get_attributes(priv->mc_io, 0, dpcon->mc_handle, &attrs);
-	if (err) {
-		dev_err(dev, "dpcon_get_attributes() failed\n");
-		goto close;
-	}
-
 	err = dpcon_enable(priv->mc_io, 0, dpcon->mc_handle);
 	if (err) {
 		dev_err(dev, "dpcon_enable() failed\n");
diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h
index 8a0e65b3267fae..686b651edcb28f 100644
--- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h
+++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h
@@ -245,6 +245,14 @@ static inline struct dpaa2_faead *dpaa2_get_faead(void *buf_addr, bool swa)
  */
 #define DPAA2_ETH_ENQUEUE_RETRIES	10
 
+/* Number of times to retry DPIO portal operations while waiting
+ * for portal to finish executing current command and become
+ * available. We want to avoid being stuck in a while loop in case
+ * hardware becomes unresponsive, but not give up too easily if
+ * the portal really is busy for valid reasons
+ */
+#define DPAA2_ETH_SWP_BUSY_RETRIES	1000
+
 /* Driver statistics, other than those in struct rtnl_link_stats64.
  * These are usually collected per-CPU and aggregated by ethtool.
  */
diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-ethtool.c b/drivers/net/ethernet/freescale/dpaa2/dpaa2-ethtool.c
index 0aa1c34019bbe8..dc9a6c36cac027 100644
--- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-ethtool.c
+++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-ethtool.c
@@ -216,7 +216,7 @@ static void dpaa2_eth_get_ethtool_stats(struct net_device *net_dev,
 		if (err == -EINVAL)
 			/* Older firmware versions don't support all pages */
 			memset(&dpni_stats, 0, sizeof(dpni_stats));
-		else
+		else if (err)
 			netdev_warn(net_dev, "dpni_get_stats(%d) failed\n", j);
 
 		num_cnt = dpni_stats_page_size[j] / sizeof(u64);