2011-05-09 10:05:05

by Daniel Drake

Subject: [PATCH] libertas: fix cmdpendingq locking

From: Paul Fox <[email protected]>

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 <[email protected]>
Signed-off-by: Daniel Drake <[email protected]>
---
drivers/net/wireless/libertas/cmd.c | 6 ++++--
1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/libertas/cmd.c b/drivers/net/wireless/libertas/cmd.c
index 7e8a658..f3ac624 100644
--- 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);
--
1.7.4.4

2011-05-09 18:18:18

by Dan Williams

Subject: Re: [PATCH] libertas: fix cmdpendingq locking

On Mon, 2011-05-09 at 10:40 +0100, Daniel Drake wrote:
> From: Paul Fox <[email protected]>
>
> 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 <[email protected]>
> Signed-off-by: Daniel Drake <[email protected]>

Acked-by: Dan Williams <[email protected]>

Also a candidate for stable@?

> ---
> drivers/net/wireless/libertas/cmd.c | 6 ++++--
> 1 files changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/wireless/libertas/cmd.c b/drivers/net/wireless/libertas/cmd.c
> index 7e8a658..f3ac624 100644
> --- 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);