libertas: fix cmdpendingq locking

commit 2ae1b8b35faba31a59b153cbad07f9c15de99740 upstream.

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>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/drivers/net/wireless/libertas/cmd.c b/drivers/net/wireless/libertas/cmd.c
index cdb9b9650d73aaf1de0114966e398defa4cae8d1..91bafae4fda50c14a763f1352a2a6b59861fbb26 100644 (file)
--- a/drivers/net/wireless/libertas/cmd.c
+++ b/drivers/net/wireless/libertas/cmd.c
@@ -1267,8 +1267,8 @@ int lbs_execute_next_command(struct lbs_private *priv)
                                    cpu_to_le16(CMD_SUBCMD_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);
 
@@ -1280,8 +1280,8 @@ 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;
@@ -1294,7 +1294,9 @@ 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);