Tobias Winter <tobias@xxxxxxxxxxxxxxx> writes: > Hi, > > I did a bit more fiddling with the usb-serial stack and got it to > support more than 256 devices. I tested it with up to 281 FTDI > singleport adapters. (After that i ran out of usb cables.. ) > > Signed-off-by: Jakob-Tobias Winter <tobias@xxxxxxxxxxxxxxx> > --- > include/linux/usb/serial.h | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/include/linux/usb/serial.h b/include/linux/usb/serial.h > index 302ddf5..ab5e01b 100644 > --- a/include/linux/usb/serial.h > +++ b/include/linux/usb/serial.h > @@ -20,7 +20,7 @@ > #include <linux/kfifo.h> > > #define SERIAL_TTY_MAJOR 188 /* Nice legal number now */ > -#define SERIAL_TTY_MINORS 254 /* loads of devices :) */ > +#define SERIAL_TTY_MINORS 512 /* loads of devices :) */ > #define SERIAL_TTY_NO_MINOR 255 /* No minor was assigned */ > > /* The maximum number of ports one device can grab at once */ Note the special meaning assigned to 255, which is the reason for the original limit being 254. I believe you need to deal with this in the allocation code if you are going to increase the number like this? Did the ttyUSB255 device work? Might be as simple as changing the SERIAL_TTY_NO_MINOR macro. I don't know.. But, IMHO, a nicer approach would be to make the allocation completely dynamic, using e.g. the idr subsystem. Static tables are always feel like straight jackets to me, no matter how big they are :) Bjørn -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
