From: Greg KH <gregkh@linuxfoundation.org>
To: Jookia <contact@jookia.org>
Cc: linux-usb@vger.kernel.org
Subject: Re: acm_port_shutdown hangs for 30 seconds
Date: Wed, 29 Jun 2022 10:37:55 +0200 [thread overview]
Message-ID: <YrwPY0faDmVcjTqx@kroah.com> (raw)
In-Reply-To: <YrrILGzC2R3qGiHu@novena-choice-citizen>
On Tue, Jun 28, 2022 at 07:21:48PM +1000, Jookia wrote:
> Hi Greg,
>
> Thanks for getting back to this!
>
> On Mon, Jun 27, 2022 at 02:57:17PM +0200, Greg KH wrote:
> > What host controller driver is this showing up on?
>
> I have the following modules loaded:
>
> xhci_pci_renesas
> xhci_pci
> xhci_hcd
>
> This isn't an ARM board or anything, this is a standard x86 desktop
> (B450 plus motherboard, Ryzen 3700x chipset)- but I believe I've had the
> same error when using serial cables on a years older computer and in
> general when doing embedded development.
>
> I believe this issue is related to buggy serial devices, in particular
> ones run by a microcontroller like an ATmega32u4 and perhaps Linux USB
> gadget where the device is abruptly reset but the serial session isn't
> terminated.
>
> The host device USB system has to time out then, which is fine, but in
> userspace this seems to hang close() instead of doing this
> asynchronously.
The close is timing out as it tries to flush the data to the device
which is no longer responding. So this kind of is expected behavior,
sorry.
greg k-h
next prev parent reply other threads:[~2022-06-29 8:38 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-12 13:58 acm_port_shutdown hangs for 30 seconds Jookia
2022-06-27 12:57 ` Greg KH
2022-06-28 9:21 ` Jookia
2022-06-29 8:37 ` Greg KH [this message]
2022-06-29 10:20 ` Jookia
2022-06-29 12:01 ` Oliver Neukum
2022-06-30 12:31 ` Jookia
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=YrwPY0faDmVcjTqx@kroah.com \
--to=gregkh@linuxfoundation.org \
--cc=contact@jookia.org \
--cc=linux-usb@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.