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[PATCH] USB: add ability for usb-serial drivers to determine if their write urb is currently being used.

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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>
This commit is contained in:
Greg Kroah-Hartman
2005-04-23 12:49:16 -07:00
parent f4df0e334a
commit 507ca9bc04
10 changed files with 85 additions and 46 deletions
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16
drivers/usb/serial/ir-usb.c
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@@ -341,10 +341,14 @@ static int ir_write (struct usb_serial_port *port, const unsigned char *buf, int
if (count == 0)
return 0;
if (port->write_urb->status == -EINPROGRESS) {
dbg ("%s - already writing", __FUNCTION__);
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);
transfer_buffer = port->write_urb->transfer_buffer;
transfer_size = min(count, port->bulk_out_size - 1);
@@ -374,9 +378,10 @@ static int ir_write (struct usb_serial_port *port, const unsigned char *buf, int
port->write_urb->transfer_flags = URB_ZERO_PACKET;
result = usb_submit_urb (port->write_urb, GFP_ATOMIC);
if (result)
if (result) {
port->write_urb_busy = 0;
dev_err(&port->dev, "%s - failed submitting write urb, error %d\n", __FUNCTION__, result);
else
} else
result = transfer_size;
return result;
@@ -387,7 +392,8 @@ static void ir_write_bulk_callback (struct urb *urb, struct pt_regs *regs)
struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
dbg("%s - port %d", __FUNCTION__, port->number);
port->write_urb_busy = 0;
if (urb->status) {
dbg("%s - nonzero write bulk status received: %d", __FUNCTION__, urb->status);
return;