Linux USB
 help / color / mirror / Atom feed
From: Alan Stern <stern@rowland.harvard.edu>
To: "M. Vefa Bicakci" <m.v.b@runbox.com>
Cc: linux-usb@vger.kernel.org,
	Andrey Konovalov <andreyknvl@google.com>,
	stable@vger.kernel.org,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Bastien Nocera <hadess@hadess.net>,
	syzkaller@googlegroups.com,
	Shuah Khan <skhan@linuxfoundation.org>
Subject: Re: [PATCH 1/3] usbcore/driver: Fix specific driver selection
Date: Fri, 18 Sep 2020 10:52:31 -0400	[thread overview]
Message-ID: <20200918145231.GA1130146@rowland.harvard.edu> (raw)
In-Reply-To: <363eab9a-c32a-4c60-4d6b-14ae8d873c52@runbox.com>

On Fri, Sep 18, 2020 at 05:31:26PM +0300, M. Vefa Bicakci wrote:
> Hello all,
> 
> I noticed that applying this patch on its own to the kernel causes the following
> unexpected behaviour: As soon as the usbip_host module is loaded, all of the
> USB devices are re-probed() by their drivers, and this causes the USB devices
> connected to my system to be momentarily unavailable. This happens because
> *without* the third patch in this patch set, the match function for the usbip_host
> device driver unconditionally returns true.
> 
> The third patch in this patch set [1] makes this unexpected behaviour go
> away, as it makes the usbip device driver's match function only match devices
> that were requested by user-space to be used with USB-IP.
> 
> Is this something to be concerned about? I was thinking of people who might be
> using git-bisect, who might encounter this issue in an unexpected manner.
> 
> As a potential solution, I can prepare another patch to revert commit
> 7a2f2974f2 ("usbip: Implement a match function to fix usbip") so that this
> unexpected behaviour will not be observed. This revert would be placed as
> the first patch in the patch series.

Yes, that sounds like a good solution.

Alan Stern

  reply	other threads:[~2020-09-18 14:52 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-16 13:33 USB driver ID matching broken Andrey Konovalov
2020-09-16 14:15 ` Greg Kroah-Hartman
2020-09-16 14:39   ` Bastien Nocera
2020-09-16 15:58     ` M. Vefa Bicakci
2020-09-17  9:59       ` [PATCH 1/2] usbcore/driver: Fix specific driver selection M. Vefa Bicakci
2020-09-17  9:59         ` [PATCH 2/2] usbip: Make the driver's match function specific M. Vefa Bicakci
2020-09-17 10:23         ` [PATCH 1/2] usbcore/driver: Fix specific driver selection Bastien Nocera
2020-09-17 10:39           ` M. Vefa Bicakci
2020-09-17 10:49             ` Bastien Nocera
2020-09-17 14:41               ` [PATCH 1/3] " M. Vefa Bicakci
2020-09-17 14:41                 ` [PATCH 2/3] usbcore/driver: Fix incorrect downcast M. Vefa Bicakci
2020-09-17 15:01                   ` Alan Stern
2020-09-18  9:26                     ` M. Vefa Bicakci
2020-09-17 14:41                 ` [PATCH 3/3] usbip: Make the driver's match function specific M. Vefa Bicakci
2020-09-17 15:21                   ` Shuah Khan
2020-09-18  9:26                     ` M. Vefa Bicakci
2020-09-18 14:31                       ` M. Vefa Bicakci
2020-09-18 15:49                         ` Shuah Khan
2020-09-19 13:54                           ` M. Vefa Bicakci
2020-09-21 17:03                             ` M. Vefa Bicakci
2020-09-18 14:31                 ` [PATCH 1/3] usbcore/driver: Fix specific driver selection M. Vefa Bicakci
2020-09-18 14:52                   ` Alan Stern [this message]
2020-09-19 13:52                     ` M. Vefa Bicakci

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=20200918145231.GA1130146@rowland.harvard.edu \
    --to=stern@rowland.harvard.edu \
    --cc=andreyknvl@google.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=hadess@hadess.net \
    --cc=linux-usb@vger.kernel.org \
    --cc=m.v.b@runbox.com \
    --cc=skhan@linuxfoundation.org \
    --cc=stable@vger.kernel.org \
    --cc=syzkaller@googlegroups.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