iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

mwifiex: remove CMD_F_CANCELED flag

Browse Source 
CMD_F_CANCELED was used to abort mwifiex_process_cmdresp in
case it already started or starts processing the cmd.
But this was probably not working the way intended:
- it is racy: mwifiex_process_cmdresp might already have passed that
  test and is continuing to use the cmd node being recycled
- mwifiex_process_cmdresp repeatedly uses adapter->curr_cmd which
  we just set to NULL
- mwifiex_recycle_cmd_node will clear the flag

The reason why it probably works is that mwifiex_cancel_pending_ioctl
is only called from mwifiex_cmd_timeout_func, where the there is little
chance of a command response still arriving

Signed-off-by: Andreas Fenkart <afenkart@gmail.com>
Acked-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
This commit is contained in:
Andreas Fenkart 2015-07-17 09:13:05 +02:00 committed by Kalle Valo
parent aeb0300083
commit e9f21d4036
2 changed files with 10 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
drivers/net/wireless/mwifiex/cmdevt.c
View File

@ -807,17 +807,6 @@ int mwifiex_process_cmdresp(struct mwifiex_adapter *adapter)
adapter->is_cmd_timedout = 0;
resp = (struct host_cmd_ds_command *) adapter->curr_cmd->resp_skb->data;
if (adapter->curr_cmd->cmd_flag & CMD_F_CANCELED) {
mwifiex_dbg(adapter, ERROR,
"CMD_RESP: %#x been canceled\n",
le16_to_cpu(resp->command));
mwifiex_recycle_cmd_node(adapter, adapter->curr_cmd);
spin_lock_irqsave(&adapter->mwifiex_cmd_lock, flags);
adapter->curr_cmd = NULL;
spin_unlock_irqrestore(&adapter->mwifiex_cmd_lock, flags);
return -1;
}
if (adapter->curr_cmd->cmd_flag & CMD_F_HOSTCMD) {
/* Copy original response back to response buffer */
struct mwifiex_ds_misc_cmd *hostcmd;
@ -1090,10 +1079,18 @@ mwifiex_cancel_pending_ioctl(struct mwifiex_adapter *adapter)
(adapter->curr_cmd->wait_q_enabled)) {
spin_lock_irqsave(&adapter->mwifiex_cmd_lock, cmd_flags);
cmd_node = adapter->curr_cmd;
cmd_node->cmd_flag |= CMD_F_CANCELED;
mwifiex_recycle_cmd_node(adapter, cmd_node);
/* setting curr_cmd to NULL is quite dangerous, because
* mwifiex_process_cmdresp checks curr_cmd to be != NULL
* at the beginning then relies on it and dereferences
* it at will
* this probably works since mwifiex_cmd_timeout_func
* is the only caller of this function and responses
* at that point
*/
adapter->curr_cmd = NULL;
spin_unlock_irqrestore(&adapter->mwifiex_cmd_lock, cmd_flags);
mwifiex_recycle_cmd_node(adapter, cmd_node);
}
/* Cancel all pending scan command */

1
drivers/net/wireless/mwifiex/fw.h
View File

@ -438,7 +438,6 @@ enum P2P_MODES {
#define CMD_F_HOSTCMD (1 << 0)
#define CMD_F_CANCELED (1 << 1)
#define HostCmd_CMD_ID_MASK 0x0fff