diff options
| author | Oliver Neukum <oneukum@suse.de> | 2007-03-15 17:27:17 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2007-04-28 00:28:36 +0400 |
| commit | 96c706ed1c46470598d785124b2a7fb233b27dab (patch) | |
| tree | e83913e0ad362043b67e163751f8a1abb0c64199 /drivers/usb/serial/io_edgeport.c | |
| parent | e198a31489146bb723fef179e5d1d18c8225f246 (diff) | |
| download | linux-96c706ed1c46470598d785124b2a7fb233b27dab.tar.xz | |
USB: io_edgeport race condition in counters
io_edgeport is using a global variable without locking.
This is _the_ classical race condition. This patch switches to atomic_t.
Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb/serial/io_edgeport.c')
| -rw-r--r-- | drivers/usb/serial/io_edgeport.c | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/drivers/usb/serial/io_edgeport.c b/drivers/usb/serial/io_edgeport.c index 6a26a2e683a6..187fd4280c88 100644 --- a/drivers/usb/serial/io_edgeport.c +++ b/drivers/usb/serial/io_edgeport.c @@ -212,7 +212,7 @@ static int debug; static int low_latency = 1; /* tty low latency flag, on by default */ -static int CmdUrbs = 0; /* Number of outstanding Command Write Urbs */ +static atomic_t CmdUrbs; /* Number of outstanding Command Write Urbs */ /* local function prototypes */ @@ -779,8 +779,8 @@ static void edge_bulk_out_cmd_callback (struct urb *urb) dbg("%s", __FUNCTION__); - CmdUrbs--; - dbg("%s - FREE URB %p (outstanding %d)", __FUNCTION__, urb, CmdUrbs); + atomic_dec(&CmdUrbs); + dbg("%s - FREE URB %p (outstanding %d)", __FUNCTION__, urb, atomic_read(&CmdUrbs)); /* clean up the transfer buffer */ @@ -2317,8 +2317,8 @@ static int write_cmd_usb (struct edgeport_port *edge_port, unsigned char *buffer if (!urb) return -ENOMEM; - CmdUrbs++; - dbg("%s - ALLOCATE URB %p (outstanding %d)", __FUNCTION__, urb, CmdUrbs); + atomic_inc(&CmdUrbs); + dbg("%s - ALLOCATE URB %p (outstanding %d)", __FUNCTION__, urb, atomic_read(&CmdUrbs)); usb_fill_bulk_urb (urb, edge_serial->serial->dev, usb_sndbulkpipe(edge_serial->serial->dev, edge_serial->bulk_out_endpoint), @@ -2332,7 +2332,7 @@ static int write_cmd_usb (struct edgeport_port *edge_port, unsigned char *buffer dev_err(&edge_port->port->dev, "%s - usb_submit_urb(write command) failed, status = %d\n", __FUNCTION__, status); usb_kill_urb(urb); usb_free_urb(urb); - CmdUrbs--; + atomic_dec(&CmdUrbs); return status; } @@ -3083,6 +3083,7 @@ static int __init edgeport_init(void) retval = usb_register(&io_driver); if (retval) goto failed_usb_register; + atomic_set(&CmdUrbs, 0); info(DRIVER_DESC " " DRIVER_VERSION); return 0; |