From 7b21f00ee6073909c01adeba317af3d78c3b9d0a Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Mon, 18 Apr 2011 09:22:10 -0700 Subject: [PATCH] iwlagn: verify that huge commands are synchronous Since huge commands all share a single buffer, there can only be a single one in flight at a time since otherwise they'd overwrite each other. This is true in the driver now, but it seems like a possible source of bugs, so add a test to verify that huge commands are always sent synchronously. Signed-off-by: Johannes Berg Signed-off-by: Wey-Yi Guy --- drivers/net/wireless/iwlwifi/iwl-tx.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/net/wireless/iwlwifi/iwl-tx.c b/drivers/net/wireless/iwlwifi/iwl-tx.c index e7faba57b6e3..1b69507db5fc 100644 --- a/drivers/net/wireless/iwlwifi/iwl-tx.c +++ b/drivers/net/wireless/iwlwifi/iwl-tx.c @@ -470,6 +470,14 @@ int iwl_enqueue_hcmd(struct iwl_priv *priv, struct iwl_host_cmd *cmd) return -EIO; } + /* + * As we only have a single huge buffer, check that the command + * is synchronous (otherwise buffers could end up being reused). + */ + + if (WARN_ON((cmd->flags & CMD_ASYNC) && (cmd->flags & CMD_SIZE_HUGE))) + return -EINVAL; + spin_lock_irqsave(&priv->hcmd_lock, flags); if (iwl_queue_space(q) < ((cmd->flags & CMD_ASYNC) ? 2 : 1)) { -- 2.20.1