On Mon, Dec 12, 2016 at 06:47:55PM +0100, Sylvain Le Gourriérec wrote:
> Hello,
>
> I don't manage to run more than one FTDI Usb Serial Adapter on a Beagle
> Bone Black. Since there is only one Usb Host port on the BBB, I tried with
> several hub (powered or not) or cape.
>
> Each time that more than one adapter is plugged, these errors appear
> (kernel 4.4 or kernel 4.9):
>
> [ 1544.135039] ftdi_sio ttyUSB0: ftdi_set_termios FAILED to set
> databits/stopbits/parity
> [ 1545.143074] ftdi_sio ttyUSB0: ftdi_set_termios urb failed to set baudrate
> [ 1550.151247] ftdi_sio ttyUSB0: urb failed to clear flow control
>
>
> Does the issue come from the FTDI driver?
No, but the error messages are printed by that driver. For some reason
these control transfers are now failing.
> I own 4 Beagle Bone Black: the problem exists on all of them.
Odd. I also have a BBB here and I have no problems connecting two FTDI
devices through a hub.
Are you using a mainline 4.9 kernel?
What kind of FTDI device are you using, and can you provide the output
of lsusb -v for them?
Could you also try running with the below diagnostics patch applied?
Thanks,
Johan
>From b5cff496d8a900af50039e3fc43c6e2ae4d2750c Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan@xxxxxxxxxx>
Date: Mon, 12 Dec 2016 19:02:20 +0100
Subject: [PATCH] USB: serial: ftdi_sio: add set_termios instrumentation
---
drivers/usb/serial/ftdi_sio.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index bf750e98d204..c3b4ea92a6a7 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -2190,6 +2190,7 @@ static void ftdi_set_termios(struct tty_struct *tty,
unsigned int iflag = termios->c_iflag;
unsigned char vstop;
unsigned char vstart;
+ int ret;
/* Force baud rate if this device requires it, unless it is set to
B0. */
@@ -2284,13 +2285,14 @@ static void ftdi_set_termios(struct tty_struct *tty,
- but is or'ed with this value */
priv->last_set_data_urb_value = urb_value;
- if (usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
+ ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
FTDI_SIO_SET_DATA_REQUEST,
FTDI_SIO_SET_DATA_REQUEST_TYPE,
urb_value , priv->interface,
- NULL, 0, WDR_SHORT_TIMEOUT) < 0) {
- dev_err(ddev, "%s FAILED to set databits/stopbits/parity\n",
- __func__);
+ NULL, 0, WDR_SHORT_TIMEOUT);
+ if (ret < 0) {
+ dev_err(ddev, "%s FAILED to set databits/stopbits/parity: %d\n",
+ __func__, ret);
}
/* Now do the baudrate */
--
2.7.3
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