libertas: Set command sequence number later to ensure consistency
Daniel Drake [Thu, 26 May 2011 20:31:08 +0000 (21:31 +0100)]
Before this patch, the command sequence number is being set before
lbs_queue_cmd() adds the command to the queue. However, lbs_queue_cmd()
sometimes forces commands to queue-jump (e.g. CMD_802_11_WAKEUP_CONFIRM).
It currently does this without considering that sequence numbers might need
adjusting to keep things running in order.

Fix this by setting the sequence number at a later stage, just before
we're actually submitting the command to the hardware. Also fixes a
possible race where seqnum was being modified outside of the driver
lock.

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

drivers/net/wireless/libertas/cmd.c

index 84566db..71c8f3f 100644 (file)
@@ -994,6 +994,8 @@ static void lbs_submit_command(struct lbs_private *priv,
        cmd = cmdnode->cmdbuf;
 
        spin_lock_irqsave(&priv->driver_lock, flags);
+       priv->seqnum++;
+       cmd->seqnum = cpu_to_le16(priv->seqnum);
        priv->cur_cmd = cmdnode;
        spin_unlock_irqrestore(&priv->driver_lock, flags);
 
@@ -1621,11 +1623,9 @@ struct cmd_ctrl_node *__lbs_cmd_async(struct lbs_private *priv,
        /* Copy the incoming command to the buffer */
        memcpy(cmdnode->cmdbuf, in_cmd, in_cmd_size);
 
-       /* Set sequence number, clean result, move to buffer */
-       priv->seqnum++;
+       /* Set command, clean result, move to buffer */
        cmdnode->cmdbuf->command = cpu_to_le16(command);
        cmdnode->cmdbuf->size    = cpu_to_le16(in_cmd_size);
-       cmdnode->cmdbuf->seqnum  = cpu_to_le16(priv->seqnum);
        cmdnode->cmdbuf->result  = 0;
 
        lbs_deb_host("PREP_CMD: command 0x%04x\n", command);