From: Alan Stern <stern@rowland.harvard.edu>
To: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Peter Hurley <peter@hurleysoftware.com>,
Nestor Lopez Casado <nlopezcasad@logitech.com>, <jkosina@suse.cz>,
<benjamin.tissoires@gmail.com>, <adlr@chromium.org>,
<joseph.salisbury@canonical.com>, <linux-input@vger.kernel.org>,
<linux-kernel@vger.kernel.org>, <linux-usb@vger.kernel.org>
Subject: Re: [PATCH 1/2] Revert "Revert "HID: Fix logitech-dj: missing Unifying device issue""
Date: Fri, 19 Jul 2013 11:14:09 -0400 (EDT) [thread overview]
Message-ID: <Pine.LNX.4.44L0.1307191008200.1055-100000@iolanthe.rowland.org> (raw)
In-Reply-To: <20130718220936.GA8025@xanatos>
On Thu, 18 Jul 2013, Sarah Sharp wrote:
> Question: does this USB device need a control transfer to reset its
> endpoints when the endpoints are not actually halted? If so, yes, that
> is a known xHCI driver bug that needs to be fixed. The xHCI host will
> not accept a Reset Endpoint command when the endpoints are not actually
> halted, but the USB core will send the control transfer to reset the
> endpoint. That means the device and host toggles will be out of sync,
> and all messages will start to fail with -EPIPE.
Why -EPIPE? Isn't that code reserved to indicate a STALL?
In fact, there's no way to detect a toggle mismatch problem with a
USB-2 device. Packets with the wrong toggle value are simply ignored
(or acknowledged and ignored). The problem ends up appearing as an
indefinite delay (for an IN transfer) or as data lost (for an OUT
transfer).
I don't know what happens with USB-3 devices when the sequence numbers
get out of alignment.
Alan Stern
next prev parent reply other threads:[~2013-07-19 15:14 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-18 13:21 [PATCH 1/2] Revert "Revert "HID: Fix logitech-dj: missing Unifying device issue"" Nestor Lopez Casado
2013-07-18 13:21 ` [PATCH 2/2] HID: hid-logitech-dj, querying_devices was never set Nestor Lopez Casado
2013-08-01 10:09 ` Benjamin Tissoires
2013-08-02 1:11 ` Jiri Kosina
2013-08-02 18:31 ` Benjamin Tissoires
2013-08-05 13:22 ` Jiri Kosina
2013-08-05 14:40 ` Benjamin Tissoires
2013-08-06 21:03 ` Sune Mølgaard
2013-08-09 9:36 ` Jiri Kosina
2013-08-10 17:21 ` Jiri Kosina
2013-07-18 20:28 ` [PATCH 1/2] Revert "Revert "HID: Fix logitech-dj: missing Unifying device issue"" Peter Hurley
2013-07-18 22:09 ` Sarah Sharp
2013-07-18 23:37 ` Peter Hurley
2013-07-19 8:35 ` Benjamin Tissoires
2013-07-19 14:38 ` Joseph Salisbury
2013-07-19 21:31 ` Peter Hurley
2013-07-22 11:44 ` Jiri Kosina
2013-07-22 14:03 ` Peter Hurley
2013-07-22 15:27 ` Alan Stern
2013-07-19 15:14 ` Alan Stern [this message]
2013-07-19 16:43 ` Nestor Lopez Casado
2013-08-12 21:54 ` Peter Wu
2013-08-13 12:13 ` Peter Hurley
2013-08-13 15:42 ` Peter Wu
2013-08-13 16:34 ` Peter Hurley
2013-07-22 14:35 ` Jiri Kosina
2013-07-22 19:21 ` Linus Torvalds
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=Pine.LNX.4.44L0.1307191008200.1055-100000@iolanthe.rowland.org \
--to=stern@rowland.harvard.edu \
--cc=adlr@chromium.org \
--cc=benjamin.tissoires@gmail.com \
--cc=jkosina@suse.cz \
--cc=joseph.salisbury@canonical.com \
--cc=linux-input@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-usb@vger.kernel.org \
--cc=nlopezcasad@logitech.com \
--cc=peter@hurleysoftware.com \
--cc=sarah.a.sharp@linux.intel.com \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).