On Mon, 2020-05-25 at 17:15 +0200, Joakim Tjernlund wrote:
> On Mon, 2020-05-25 at 17:02 +0200, Oliver Neukum wrote:
> > CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you recognize the sender and know the content is safe.
> >
> >
> > Am Montag, den 25.05.2020, 14:46 +0000 schrieb Joakim Tjernlund:
> >
> > > This (EMI?) disconnect causes 2 things.
> > > 1) I loose the TTY temporarily and have to reconnect.
> >
> > Unfortunately I see no way to reestablish contact transparantly
> > on the level of the driver.
> >
> > > 2) After reconnect there are garbage chars on the gadget side, such as:
> > > h�^@^@� ^@^@� ^@
> >
> > This looks like MM is acting up in user space.
> >
> > > or
> > > X���)H��4Ğ^���
> > > which causes confusion on for the tty/bash on the gadget.
> > >
> > > The disconnect is mostly just annoying but the garbage chars are a major pain, one cannot trust
> > > that cmds are understod. Is there a bug in ttyACM driver causing these?
> >
> > Hi,
> >
> > thanks for the bug report. The most likely cause of your problem is
> > ModemManager probing the new device. It has a blacklist.
>
> No, I have already blacklisted this device from modemmanger, is blacklist not reliable in this case?
>
> Jocke
>
To be clear, I can pull the cable and put it back and there are no garbage chars.
There is also this error:
[Wed May 20 14:03:25 2020] cdc_acm 1-6.3:1.1: acm_ctrl_irq - usb_submit_urb failed: -19
[Wed May 20 14:03:25 2020] usb 1-6-port2: attempt power cycle
[Wed May 20 14:03:26 2020] usb 1-6.3: USB disconnect, device number 86
[Wed May 20 14:03:26 2020] cdc_acm 1-6.3:1.1: failed to set dtr/rts
Should not this auto reenable emulate reattaching the USB cable?
Jocke
