[ Adding linux-usb to CC. ] On Wed, Oct 15, 2014 at 03:55:15PM +0400, Victor Ashik wrote: > Hello Johan, > > Sorry for asking you directly, I found your address in the top comment of > ftdi_sio.c in Linux sources. I think that you know a short answer to my > question. Sorry for a long explanation below, I am trying to be as specific > as possible. > > I am trying to get my decade-old FTDI 8U100AX-based USB-serial converter > working with Linux. I checked that it works with NetBSD and does not work > with Linux. > > On Linux I see error messages in dmesg: > [53627.263480] ftdi_sio ttyUSB0: Unable to read latency timer: -32 > [53627.264295] ftdi_sio ttyUSB0: Unable to write latency timer: -32 The driver should still work even if the device doesn't support setting the latency timer. > RX/DX leds on connected via USB-Serial analog modem are blinking very fast > and I do not get correct response from the modem to AT commands. > > I am trying to realize what is going on by looking at the code. I found > that my defice may require the extra byte transmitted with the data: > > https://github.com/juanfra684/netbsd-src/blob/b00c2cff78f467ead9e6468be4379e23bfc8c33f/sys/dev/usb/uftdi.c#L221 > > Was that this support dropped from the code? Or was it there at all? > > https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/drivers/usb/serial/ftdi_sio.c?id=refs/tags/v3.17#n1915 No, we're still supposed to support the legacy SIO type of devices, although that code doesn't get much testing I'm afraid. But let's start with verifying that the type is actually detected. Could you post the kernel log from when plugging the device in along with the "lsusb -v" output for it? Thanks, Johan -- 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
