On Wed, May 27, 2015 at 03:50:34PM -0000, Karl Palsson wrote: > > Johan Hovold <jo...@kernel.org> wrote: > > > > > > The usbmon traces seem to be a continual reporting of the "0x0160" shown > > > in the ftdi_get_modem_status lines. Is this actually _meant_ to be > > > happening? Can I turn it off? Any other suggestions? > > > > This is the device reporting the modem and line status every > > millisecond. You can increase the interval by clearing the low_latency > > flag and setting a even higher value than the otherwise default 16ms > > period through sysfs. > > > > Note that this also means that any data received will not necessarily be > > forwarded every millisecond either anymore. > > > > Ok, I've now seen that this is actually happening with my ftdi ft232 > devices on desktop linux too [1], but not for my cp210x, and not for a > ch341 device
Different chips have different protocols and ways of communicating from the host to the device. > If I'm not interested in modem status, can I disable this entirely? I > don't even have modem lines connected. Is this data packet somehow causing a problem with your system? If so, I suggest using a different type of usb to serial device, but it might be hard to find a device that doesn't do some kind of communication when the port is open, that's how data is received from the device :) thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
