mvebu: remove linux 4.4 support

[openwrt/staging/lynxis/omap.git] / target / linux / mvebu / patches-4.4 / 042-net-mvneta-Fix-race-condition-during-stopping.patch

diff --git a/target/linux/mvebu/patches-4.4/042-net-mvneta-Fix-race-condition-during-stopping.patch b/target/linux/mvebu/patches-4.4/042-net-mvneta-Fix-race-condition-during-stopping.patch
deleted file mode 100644 (file)
index 9936ebf..0000000
--- a/target/linux/mvebu/patches-4.4/042-net-mvneta-Fix-race-condition-during-stopping.patch
+++ /dev/null
@@ -1,128 +0,0 @@
-From: Gregory CLEMENT <gregory.clement@free-electrons.com>
-Date: Thu, 4 Feb 2016 22:09:29 +0100
-Subject: [PATCH] net: mvneta: Fix race condition during stopping
-
-When stopping the port, the CPU notifier are still there whereas the
-mvneta_stop_dev function calls mvneta_percpu_disable() on each CPUs.
-It was possible to have a new CPU coming at this point which could be
-racy.
-
-This patch adds a flag preventing executing the code notifier for a new
-CPU when the port is stopping. It also uses the spinlock introduces
-previously. To avoid the deadlock, the lock has been moved outside the
-mvneta_percpu_elect function.
-
-Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
-Signed-off-by: David S. Miller <davem@davemloft.net>
----
-
---- a/drivers/net/ethernet/marvell/mvneta.c
-+++ b/drivers/net/ethernet/marvell/mvneta.c
-@@ -374,6 +374,7 @@ struct mvneta_port {
-        * ensuring that the configuration remains coherent.
-        */
-       spinlock_t lock;
-+      bool is_stopped;
- 
-       /* Core clock */
-       struct clk *clk;
-@@ -2853,16 +2854,14 @@ static void mvneta_percpu_disable(void *
-       disable_percpu_irq(pp->dev->irq);
- }
- 
-+/* Electing a CPU must be done in an atomic way: it should be done
-+ * after or before the removal/insertion of a CPU and this function is
-+ * not reentrant.
-+ */
- static void mvneta_percpu_elect(struct mvneta_port *pp)
- {
-       int elected_cpu = 0, max_cpu, cpu, i = 0;
- 
--      /* Electing a CPU must be done in an atomic way: it should be
--       * done after or before the removal/insertion of a CPU and
--       * this function is not reentrant.
--       */
--      spin_lock(&pp->lock);
--
-       /* Use the cpu associated to the rxq when it is online, in all
-        * the other cases, use the cpu 0 which can't be offline.
-        */
-@@ -2906,7 +2905,6 @@ static void mvneta_percpu_elect(struct m
-               i++;
- 
-       }
--      spin_unlock(&pp->lock);
- };
- 
- static int mvneta_percpu_notifier(struct notifier_block *nfb,
-@@ -2920,6 +2918,14 @@ static int mvneta_percpu_notifier(struct
-       switch (action) {
-       case CPU_ONLINE:
-       case CPU_ONLINE_FROZEN:
-+              spin_lock(&pp->lock);
-+              /* Configuring the driver for a new CPU while the
-+               * driver is stopping is racy, so just avoid it.
-+               */
-+              if (pp->is_stopped) {
-+                      spin_unlock(&pp->lock);
-+                      break;
-+              }
-               netif_tx_stop_all_queues(pp->dev);
- 
-               /* We have to synchronise on tha napi of each CPU
-@@ -2957,6 +2963,7 @@ static int mvneta_percpu_notifier(struct
-                       MVNETA_CAUSE_LINK_CHANGE |
-                       MVNETA_CAUSE_PSC_SYNC_CHANGE);
-               netif_tx_start_all_queues(pp->dev);
-+              spin_unlock(&pp->lock);
-               break;
-       case CPU_DOWN_PREPARE:
-       case CPU_DOWN_PREPARE_FROZEN:
-@@ -2981,7 +2988,9 @@ static int mvneta_percpu_notifier(struct
-       case CPU_DEAD:
-       case CPU_DEAD_FROZEN:
-               /* Check if a new CPU must be elected now this on is down */
-+              spin_lock(&pp->lock);
-               mvneta_percpu_elect(pp);
-+              spin_unlock(&pp->lock);
-               /* Unmask all ethernet port interrupts */
-               on_each_cpu(mvneta_percpu_unmask_interrupt, pp, true);
-               mvreg_write(pp, MVNETA_INTR_MISC_MASK,
-@@ -3033,7 +3042,7 @@ static int mvneta_open(struct net_device
-        */
-       on_each_cpu(mvneta_percpu_enable, pp, true);
- 
--
-+      pp->is_stopped = false;
-       /* Register a CPU notifier to handle the case where our CPU
-        * might be taken offline.
-        */
-@@ -3066,9 +3075,18 @@ static int mvneta_stop(struct net_device
- {
-       struct mvneta_port *pp = netdev_priv(dev);
- 
-+      /* Inform that we are stopping so we don't want to setup the
-+       * driver for new CPUs in the notifiers
-+       */
-+      spin_lock(&pp->lock);
-+      pp->is_stopped = true;
-       mvneta_stop_dev(pp);
-       mvneta_mdio_remove(pp);
-       unregister_cpu_notifier(&pp->cpu_notifier);
-+      /* Now that the notifier are unregistered, we can release le
-+       * lock
-+       */
-+      spin_unlock(&pp->lock);
-       on_each_cpu(mvneta_percpu_disable, pp, true);
-       free_percpu_irq(dev->irq, pp->ports);
-       mvneta_cleanup_rxqs(pp);
-@@ -3339,7 +3357,9 @@ static int  mvneta_config_rss(struct mvn
-       mvreg_write(pp, MVNETA_PORT_CONFIG, val);
- 
-       /* Update the elected CPU matching the new rxq_def */
-+      spin_lock(&pp->lock);
-       mvneta_percpu_elect(pp);
-+      spin_unlock(&pp->lock);
- 
-       /* We have to synchronise on the napi of each CPU */
-       for_each_online_cpu(cpu) {