r8169: Clear RTL_FLAG_TASK_*_PENDING when clearing RTL_FLAG_TASK_ENABLED

After system suspend, sometimes the r8169 doesn't work when ethernet
cable gets pluggued.

This issue happens because rtl_reset_work() doesn't get called from
rtl8169_runtime_resume(), after system suspend.

In rtl_task(), RTL_FLAG_TASK_* only gets cleared if this condition is
met:
if (!netif_running(dev) ||
    !test_bit(RTL_FLAG_TASK_ENABLED, tp->wk.flags))
    ...

If RTL_FLAG_TASK_ENABLED was cleared during system suspend while
RTL_FLAG_TASK_RESET_PENDING was set, the next rtl_schedule_task() won't
schedule task as the flag is still there.

So in addition to clearing RTL_FLAG_TASK_ENABLED, also clears other
flags.

Cc: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/realtek/r8169.c

@@ -631,7 +631,7 @@ struct rtl8169_tc_offsets {
 };
 
 enum rtl_flag {
-	RTL_FLAG_TASK_ENABLED,
+	RTL_FLAG_TASK_ENABLED = 0,
 	RTL_FLAG_TASK_SLOW_PENDING,
 	RTL_FLAG_TASK_RESET_PENDING,
 	RTL_FLAG_MAX
@@ -6655,7 +6655,8 @@ static int rtl8169_close(struct net_device *dev)
 	rtl8169_update_counters(tp);
 
 	rtl_lock_work(tp);
-	clear_bit(RTL_FLAG_TASK_ENABLED, tp->wk.flags);
+	/* Clear all task flags */
+	bitmap_zero(tp->wk.flags, RTL_FLAG_MAX);
 
 	rtl8169_down(dev);
 	rtl_unlock_work(tp);
@@ -6838,7 +6839,9 @@ static void rtl8169_net_suspend(struct net_device *dev)
 
 	rtl_lock_work(tp);
 	napi_disable(&tp->napi);
-	clear_bit(RTL_FLAG_TASK_ENABLED, tp->wk.flags);
+	/* Clear all task flags */
+	bitmap_zero(tp->wk.flags, RTL_FLAG_MAX);
+
 	rtl_unlock_work(tp);
 
 	rtl_pll_power_down(tp);