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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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14
drivers/usb/serial/ipw.c
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@@ -399,16 +399,21 @@ static int ipw_write(struct usb_serial_port *port, const unsigned char *buf, int
dbg("%s - write request of 0 bytes", __FUNCTION__);
return 0;
}
/* Racy and broken, FIXME properly! */
if (port->write_urb->status == -EINPROGRESS)
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);
count = min(count, port->bulk_out_size);
memcpy(port->bulk_out_buffer, buf, count);
dbg("%s count now:%d", __FUNCTION__, count);
usb_fill_bulk_urb(port->write_urb, dev,
usb_sndbulkpipe(dev, port->bulk_out_endpointAddress),
port->write_urb->transfer_buffer,
@@ -418,6 +423,7 @@ static int ipw_write(struct usb_serial_port *port, const unsigned char *buf, int
ret = usb_submit_urb(port->write_urb, GFP_ATOMIC);
if (ret != 0) {
port->write_urb_busy = 0;
dbg("%s - usb_submit_urb(write bulk) failed with error = %d", __FUNCTION__, ret);
return ret;
}