libertas: fix cmdpendingq locking

We occasionally see list corruption using libertas.

While we haven't been able to diagnose this precisely, we have spotted
a possible cause: cmdpendingq is generally modified with driver_lock
held. However, there are a couple of points where this is not the case.

Fix up those operations to execute under the lock, it seems like
the correct thing to do and will hopefully improve the situation.

Signed-off-by: Paul Fox <pgf@laptop.org>
Signed-off-by: Daniel Drake <dsd@laptop.org>
Acked-by: Dan Williams <dcbw@redhat.com>
Cc: stable@kernel.org
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/drivers/net/wireless/libertas/cmd.c b/drivers/net/wireless/libertas/cmd.c
index 7e8a658b7670ee580b5a8a84094beb9c6de86dd7..f3ac62431a3085c7eee695e98987ba140cb53d02 100644 (file)
--- a/drivers/net/wireless/libertas/cmd.c
+++ b/drivers/net/wireless/libertas/cmd.c
@@ -1339,8 +1339,8 @@ int lbs_execute_next_command(struct lbs_private *priv)
                                    cpu_to_le16(PS_MODE_ACTION_EXIT_PS)) {
                                        lbs_deb_host(
                                               "EXEC_NEXT_CMD: ignore ENTER_PS cmd\n");
-                                       list_del(&cmdnode->list);
                                        spin_lock_irqsave(&priv->driver_lock, flags);
+                                       list_del(&cmdnode->list);
                                        lbs_complete_command(priv, cmdnode, 0);
                                        spin_unlock_irqrestore(&priv->driver_lock, flags);
 
@@ -1352,8 +1352,8 @@ int lbs_execute_next_command(struct lbs_private *priv)
                                    (priv->psstate == PS_STATE_PRE_SLEEP)) {
                                        lbs_deb_host(
                                               "EXEC_NEXT_CMD: ignore EXIT_PS cmd in sleep\n");
-                                       list_del(&cmdnode->list);
                                        spin_lock_irqsave(&priv->driver_lock, flags);
+                                       list_del(&cmdnode->list);
                                        lbs_complete_command(priv, cmdnode, 0);
                                        spin_unlock_irqrestore(&priv->driver_lock, flags);
                                        priv->needtowakeup = 1;
@@ -1366,7 +1366,9 @@ int lbs_execute_next_command(struct lbs_private *priv)
                                       "EXEC_NEXT_CMD: sending EXIT_PS\n");
                        }
                }
+               spin_lock_irqsave(&priv->driver_lock, flags);
                list_del(&cmdnode->list);
+               spin_unlock_irqrestore(&priv->driver_lock, flags);
                lbs_deb_host("EXEC_NEXT_CMD: sending command 0x%04x\n",
                            le16_to_cpu(cmd->command));
                lbs_submit_command(priv, cmdnode);