Upgrade to 4.4.50-rt62

The current kernel is based on rt kernel v4.4.6-rt14. We will upgrade it
to 4.4.50-rt62.
The command to achieve it is:
a) Clone a git repo from
git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git

b) Get the diff between this two changesets:
git diff 640eca2901f3435e616157b11379d3223a44b391
705619beeea1b0b48219a683fd1a901a86fdaf5e

where the two commits are:
[yjiang5@jnakajim-build linux-stable-rt]$ git show --oneline --name-only
640eca2901f3435e616157b11379d3223a44b391
640eca2901f3 v4.4.6-rt14
localversion-rt
[yjiang5@jnakajim-build linux-stable-rt]$ git show --oneline --name-only
705619beeea1b0b48219a683fd1a901a86fdaf5e
705619beeea1 Linux 4.4.50-rt62
localversion-rt

c) One patch has been backported thus revert the patch before applying.

 filterdiff -p1 -x scripts/package/Makefile
~/tmp/v4.4.6-rt14-4.4.50-rt62.diff  |patch -p1 --dry-run

Upstream status: backport

Change-Id: I244d57a32f6066e5a5b9915f9fbf99e7bbca6e01
Signed-off-by: Yunhong Jiang <yunhong.jiang@linux.intel.com>

1 files changed, 18 insertions, 7 deletions

diff --git a/kernel/drivers/net/ethernet/broadcom/bcmsysport.c b/kernel/drivers/net/ethernet/broadcom/bcmsysport.c
index 858106352..8860e74aa 100644
--- a/kernel/drivers/net/ethernet/broadcom/bcmsysport.c
+++ b/kernel/drivers/net/ethernet/broadcom/bcmsysport.c
@@ -732,11 +732,8 @@ static unsigned int __bcm_sysport_tx_reclaim(struct bcm_sysport_priv *priv,
 	unsigned int c_index, last_c_index, last_tx_cn, num_tx_cbs;
 	unsigned int pkts_compl = 0, bytes_compl = 0;
 	struct bcm_sysport_cb *cb;
-	struct netdev_queue *txq;
 	u32 hw_ind;
 
-	txq = netdev_get_tx_queue(ndev, ring->index);
-
 	/* Compute how many descriptors have been processed since last call */
 	hw_ind = tdma_readl(priv, TDMA_DESC_RING_PROD_CONS_INDEX(ring->index));
 	c_index = (hw_ind >> RING_CONS_INDEX_SHIFT) & RING_CONS_INDEX_MASK;
@@ -767,9 +764,6 @@ static unsigned int __bcm_sysport_tx_reclaim(struct bcm_sysport_priv *priv,
 
 	ring->c_index = c_index;
 
-	if (netif_tx_queue_stopped(txq) && pkts_compl)
-		netif_tx_wake_queue(txq);
-
 	netif_dbg(priv, tx_done, ndev,
 		  "ring=%d c_index=%d pkts_compl=%d, bytes_compl=%d\n",
 		  ring->index, ring->c_index, pkts_compl, bytes_compl);
@@ -781,16 +775,33 @@ static unsigned int __bcm_sysport_tx_reclaim(struct bcm_sysport_priv *priv,
 static unsigned int bcm_sysport_tx_reclaim(struct bcm_sysport_priv *priv,
 					   struct bcm_sysport_tx_ring *ring)
 {
+	struct netdev_queue *txq;
 	unsigned int released;
 	unsigned long flags;
 
+	txq = netdev_get_tx_queue(priv->netdev, ring->index);
+
 	spin_lock_irqsave(&ring->lock, flags);
 	released = __bcm_sysport_tx_reclaim(priv, ring);
+	if (released)
+		netif_tx_wake_queue(txq);
+
 	spin_unlock_irqrestore(&ring->lock, flags);
 
 	return released;
 }
 
+/* Locked version of the per-ring TX reclaim, but does not wake the queue */
+static void bcm_sysport_tx_clean(struct bcm_sysport_priv *priv,
+				 struct bcm_sysport_tx_ring *ring)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&ring->lock, flags);
+	__bcm_sysport_tx_reclaim(priv, ring);
+	spin_unlock_irqrestore(&ring->lock, flags);
+}
+
 static int bcm_sysport_tx_poll(struct napi_struct *napi, int budget)
 {
 	struct bcm_sysport_tx_ring *ring =
@@ -1275,7 +1286,7 @@ static void bcm_sysport_fini_tx_ring(struct bcm_sysport_priv *priv,
 	napi_disable(&ring->napi);
 	netif_napi_del(&ring->napi);
 
-	bcm_sysport_tx_reclaim(priv, ring);
+	bcm_sysport_tx_clean(priv, ring);
 
 	kfree(ring->cbs);
 	ring->cbs = NULL;