diff options
| author | Greg Kroah-Hartman <gregkh@suse.de> | 2005-04-23 23:49:16 +0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2005-06-28 01:43:47 +0400 |
| commit | 507ca9bc0476662f3463888d583864834eab1e11 (patch) | |
| tree | 421a373de235fcb4cb46a4723a1e9f00a71f709a /drivers/usb/serial/safe_serial.c | |
| parent | f4df0e334a9fc731689e8ba4f42a0d72a7491348 (diff) | |
| download | linux-507ca9bc0476662f3463888d583864834eab1e11.tar.xz | |
[PATCH] USB: add ability for usb-serial drivers to determine if their write urb is currently being used.
This removes a lot of racy and buggy code by trying to check the status of the urb.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb/serial/safe_serial.c')
| -rw-r--r-- | drivers/usb/serial/safe_serial.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/drivers/usb/serial/safe_serial.c b/drivers/usb/serial/safe_serial.c index 0e85ed6c6c19..96a17568cbf1 100644 --- a/drivers/usb/serial/safe_serial.c +++ b/drivers/usb/serial/safe_serial.c @@ -299,10 +299,14 @@ static int safe_write (struct usb_serial_port *port, const unsigned char *buf, i dbg ("%s - write request of 0 bytes", __FUNCTION__); return (0); } - if (port->write_urb->status == -EINPROGRESS) { - dbg ("%s - already writing", __FUNCTION__); - return (0); + spin_lock(&port->lock); + if (port->write_urb_busy) { + spin_unlock(&port->lock); + dbg("%s - already writing", __FUNCTION__); + return 0; } + port->write_urb_busy = 1; + spin_unlock(&port->lock); packet_length = port->bulk_out_size; // get max packetsize @@ -354,6 +358,7 @@ static int safe_write (struct usb_serial_port *port, const unsigned char *buf, i #endif port->write_urb->dev = port->serial->dev; if ((result = usb_submit_urb (port->write_urb, GFP_KERNEL))) { + port->write_urb_busy = 0; err ("%s - failed submitting write urb, error %d", __FUNCTION__, result); return 0; } @@ -368,7 +373,7 @@ static int safe_write_room (struct usb_serial_port *port) dbg ("%s", __FUNCTION__); - if (port->write_urb->status != -EINPROGRESS) + if (port->write_urb_busy) room = port->bulk_out_size - (safe ? 2 : 0); if (room) { |