mac802154: cfg: add suspend and resume callbacks

This patch introduces suspend and resume callbacks to mac802154. When
doing suspend we calling the stop driver callback which should stop the
receiving of frames. A transceiver should go into low-power mode then.
Calling resume will call the start driver callback, which starts receiving
again and allow to transmit frames.

This was tested only with the fakelb driver and a qemu vm by doing the
following commands:

echo "devices" > /sys/power/pm_test
echo "freeze" > /sys/power/state

while doing some high traffic between two fakelb phys.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

3 files changed, 54 insertions, 2 deletions

diff --git a/net/mac802154/cfg.c b/net/mac802154/cfg.c
index 44db8613812e..f7ba51e8b4ca 100644
--- a/net/mac802154/cfg.c
+++ b/net/mac802154/cfg.c
@@ -44,6 +44,49 @@ static void ieee802154_del_iface_deprecated(struct wpan_phy *wpan_phy,
         ieee802154_if_remove(sdata);
 }
 
+#ifdef CONFIG_PM
+static int ieee802154_suspend(struct wpan_phy *wpan_phy)
+{
+        struct ieee802154_local *local = wpan_phy_priv(wpan_phy);
+
+        if (!local->open_count)
+                goto suspend;
+
+        ieee802154_stop_queue(&local->hw);
+        synchronize_net();
+
+        /* stop hardware - this must stop RX */
+        ieee802154_stop_device(local);
+
+suspend:
+        local->suspended = true;
+        return 0;
+}
+
+static int ieee802154_resume(struct wpan_phy *wpan_phy)
+{
+        struct ieee802154_local *local = wpan_phy_priv(wpan_phy);
+        int ret;
+
+        /* nothing to do if HW shouldn't run */
+        if (!local->open_count)
+                goto wake_up;
+
+        /* restart hardware */
+        ret = drv_start(local);
+        if (ret)
+                return ret;
+
+wake_up:
+        ieee802154_wake_queue(&local->hw);
+        local->suspended = false;
+        return 0;
+}
+#else
+#define ieee802154_suspend NULL
+#define ieee802154_resume NULL
+#endif
+
 static int
 ieee802154_add_iface(struct wpan_phy *phy, const char *name,
                      unsigned char name_assign_type,
@@ -232,6 +275,8 @@ ieee802154_set_lbt_mode(struct wpan_phy *wpan_phy, struct wpan_dev *wpan_dev,
 const struct cfg802154_ops mac802154_config_ops = {
         .add_virtual_intf_deprecated = ieee802154_add_iface_deprecated,
         .del_virtual_intf_deprecated = ieee802154_del_iface_deprecated,
+        .suspend = ieee802154_suspend,
+        .resume = ieee802154_resume,
         .add_virtual_intf = ieee802154_add_iface,
         .del_virtual_intf = ieee802154_del_iface,
         .set_channel = ieee802154_set_channel,
diff --git a/net/mac802154/ieee802154_i.h b/net/mac802154/ieee802154_i.h
index 04077830e88c..0054f39d499b 100644
--- a/net/mac802154/ieee802154_i.h
+++ b/net/mac802154/ieee802154_i.h
@@ -56,6 +56,7 @@ struct ieee802154_local {
         struct hrtimer ifs_timer;
 
         bool started;
+        bool suspended;
 
         struct tasklet_struct tasklet;
         struct sk_buff_head skb_queue;
diff --git a/net/mac802154/rx.c b/net/mac802154/rx.c
index d93ad2d4a4fc..5a258c11ed3b 100644
--- a/net/mac802154/rx.c
+++ b/net/mac802154/rx.c
@@ -253,6 +253,9 @@ void ieee802154_rx(struct ieee802154_hw *hw, struct sk_buff *skb)
 
         WARN_ON_ONCE(softirq_count() == 0);
 
+        if (local->suspended)
+                goto drop;
+
         /* TODO: When a transceiver omits the checksum here, we
          * add an own calculated one. This is currently an ugly
          * solution because the monitor needs a crc here.
@@ -273,8 +276,7 @@ void ieee802154_rx(struct ieee802154_hw *hw, struct sk_buff *skb)
                 crc = crc_ccitt(0, skb->data, skb->len);
                 if (crc) {
                         rcu_read_unlock();
-                        kfree_skb(skb);
-                        return;
+                        goto drop;
                 }
         }
         /* remove crc */
@@ -283,6 +285,10 @@ void ieee802154_rx(struct ieee802154_hw *hw, struct sk_buff *skb)
         __ieee802154_rx_handle_packet(local, skb);
 
         rcu_read_unlock();
+
+        return;
+drop:
+        kfree_skb(skb);
 }
 EXPORT_SYMBOL(ieee802154_rx);