Messages in this thread | | | Date | Fri, 3 Jul 2015 10:49:32 +0200 | Subject | Re: [TRIVIAL PATCH] usb/serial.h: Increase max number of serial ports per USB-serial device | From | Bartosz Tomeczko <> |
| |
2015-07-03 10:28 GMT+02:00 Johan Hovold <johan@kernel.org>: > On Thu, Jul 02, 2015 at 05:13:47PM +0200, Bartosz Tomeczko wrote: >> Hello, >> >> I am using MOXA USB-to-serial converter with 16 serial ports. This >> device is namely a MOXA UPort 1650-16. This device works as a simple >> usb-serial adapter and therefore its driver uses >> include/linux/usb/serial.h file. In this very file however maximal >> number of serial ports served by the driver is eight (MAX_NUM_PORTS). >> I would like to propose a trivial patch which would allow MOXA users >> to use all ports of the device instead of just having eight of them >> usable (as it is right now). Trivial change which might be applied on >> the top of (4da3064d1775810f10f7ddc1c34c3f1ff502a654) is as follows: >> >> diff --git a/include/linux/usb/serial.h b/include/linux/usb/serial.h >> index 704a1ab..b7af736 100644 >> --- a/include/linux/usb/serial.h >> +++ b/include/linux/usb/serial.h >> @@ -20,7 +20,7 @@ >> #include <linux/kfifo.h> >> >> /* The maximum number of ports one device can grab at once */ >> -#define MAX_NUM_PORTS 8 >> +#define MAX_NUM_PORTS 16 >> >> /* parity check flag */ >> #define RELEVANT_IFLAG(iflag) (iflag & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK)) > > I'm aware that this limit is too low be able to use all ports on that > Moxa device. I have some patches lying around that I never got to finish > that clean up the descriptor handling and removes the arbitrary port > limitation completely. > > Let me revisit those, and I'll make sure this gets fixed for 4.3. > > Thanks, > Johan
Hello Johan,
Thanks for that! So we are staying tuned for upcoming changes. Meanwhile we will keep our kernel patched locally to support more that eight ports.
Have a nice day. Bartosz
| |