Re: [PATCH 1/5] usb_debug: implement multi urb write

[Greg KH <greg@kroah.com>]

On Tue, May 05, 2009 at 09:00:01PM -0500, Jason Wessel wrote:
> The usb_debug driver, when used as the console, will always fail to
> insert the carriage return and new line sequence as well as randomly
> drop console output.  This is a result of only having the single
> write_urb and that the tty layer will have a lock that prevents the
> processing of the back to back urb requests.
> 
> The solution is to allow more than one urb to be outstanding and have
> a slightly deeper transmit queue.  The idea and some code is borrowed
> from the ftdi_sio usb driver.

Almost all usb-serial drivers need this functionality.

As you are adding it to the usb_debug driver, why not just add this kind
of functionality to the usb-serial core instead, that way we can share
it with all of the drivers?  I'd much rather see that happen instead of
us doing it individually again.

thanks,

greg k-h