From: Pavel Machek <pavel@ucw.cz>
To: Vladimir Stankovic <vladimir.stankovic@displaylink.com>
Cc: Greg KH <gregkh@linuxfoundation.org>,
linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org,
mausb-host-devel@displaylink.com
Subject: Re: [External] Re: [PATCH v5 0/8] Add MA USB Host driver
Date: Fri, 29 May 2020 14:48:43 +0200 [thread overview]
Message-ID: <20200529124843.GA1339@bug> (raw)
In-Reply-To: <f0a4432e-d14a-0108-7d6e-edb648b6393f@displaylink.com>
Hi!
> >>>> MA USB protocol used by MA USB Host driver has been implemented in
> >>>> accordance with MA USB Specification Release 1.0b.
> >>>
> >>> Is that a USB-released spec?
> >> Correct, document is being maintained by USB IF and is publicly available.
> >> However, I just noticed a typo, correct version is 1.0a. Will correct.
> >>
> >> In short, MA USB Specification defines an MA USB protocol that performs USB
> >> communication via any communication medium. As such, it defines how to pack
> >> USB data within MA USB payload, and how to communicate with remote MA USB device.
Ok
> >> Userspace code is not publicly available. However, in short, it's purpose is
> >> twofold, to provide interface to application layer, and to prepare MA USB packets
> >> that will be used by remote device.
> >
> > So you want us to take a one-off char-driver kernel code for a closed
> > source userspace application for a public spec? That feels really
> > really odd, if not actually against a few licenses. I hate to ask it,
> > but are your lawyers ok with this?
More importantly... does that work?
Userland is okay for communication setup, but if userspace is involved with every packet
being sent... It will deadlock.
One example: attach mass storage device over MUSB, put swap there; what happens if your
userland helper is now swapped out?
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
next prev parent reply other threads:[~2020-05-29 12:48 UTC|newest]
Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-12 14:42 [PATCH v3 0/8] Add MA USB Host driver Vladimir Stankovic
2020-03-27 15:26 ` [PATCH v4 " vladimir.stankovic
2020-03-27 15:26 ` [PATCH v4 1/8] usb: Add MA-USB Host kernel module vladimir.stankovic
2020-03-27 16:25 ` Alan Stern
2020-03-27 15:26 ` [PATCH v4 2/8] usb: mausb_host: Add link layer implementation vladimir.stankovic
2020-03-27 15:26 ` [PATCH v4 3/8] usb: mausb_host: HCD initialization vladimir.stankovic
2020-03-27 15:26 ` [PATCH v4 4/8] usb: mausb_host: Implement initial hub handlers vladimir.stankovic
2020-03-27 16:37 ` Alan Stern
2020-04-13 15:16 ` Vladimir Stankovic
2020-03-27 15:26 ` [PATCH v4 5/8] usb: mausb_host: Introduce PAL processing vladimir.stankovic
2020-03-27 16:35 ` Alan Stern
2020-03-28 3:56 ` kbuild test robot
2020-03-27 15:26 ` [PATCH v4 6/8] usb: mausb_host: Add logic for PAL-to-PAL communication vladimir.stankovic
2020-03-27 15:26 ` [PATCH v4 7/8] usb: mausb_host: MA-USB PAL events processing vladimir.stankovic
2020-03-28 10:35 ` kbuild test robot
2020-04-04 16:07 ` kbuild test robot
2020-03-27 15:26 ` [PATCH v4 8/8] usb: mausb_host: Process MA-USB data packets vladimir.stankovic
2020-04-25 9:19 ` [PATCH v5 0/8] Add MA USB Host driver vladimir.stankovic
2020-04-25 9:19 ` [PATCH v5 1/8] usb: Add MA-USB Host kernel module vladimir.stankovic
2020-04-28 11:03 ` Greg KH
2020-04-25 9:19 ` [PATCH v5 2/8] usb: mausb_host: Add link layer implementation vladimir.stankovic
2020-04-25 9:19 ` [PATCH v5 3/8] usb: mausb_host: HCD initialization vladimir.stankovic
2020-04-28 11:07 ` Greg KH
2020-04-25 9:19 ` [PATCH v5 4/8] usb: mausb_host: Implement initial hub handlers vladimir.stankovic
2020-04-25 9:19 ` [PATCH v5 5/8] usb: mausb_host: Introduce PAL processing vladimir.stankovic
2020-04-26 0:32 ` Alan Stern
2020-04-26 12:32 ` Vladimir Stankovic
2020-04-26 14:31 ` Alan Stern
2020-04-26 14:45 ` [External] " Vladimir Stankovic
2020-04-26 20:56 ` Alan Stern
2020-04-30 14:37 ` Vladimir Stankovic
2020-04-30 15:18 ` Alan Stern
2020-04-30 15:34 ` Vladimir Stankovic
2020-04-30 15:41 ` Alan Stern
2020-04-25 9:19 ` [PATCH v5 6/8] usb: mausb_host: Add logic for PAL-to-PAL communication vladimir.stankovic
2020-04-25 9:19 ` [PATCH v5 7/8] usb: mausb_host: MA-USB PAL events processing vladimir.stankovic
2020-04-28 11:08 ` Greg KH
2020-04-25 9:19 ` [PATCH v5 8/8] usb: mausb_host: Process MA-USB data packets vladimir.stankovic
2020-04-28 11:04 ` [PATCH v5 0/8] Add MA USB Host driver Greg KH
2020-04-30 16:51 ` [External] " Vladimir Stankovic
2020-04-30 20:02 ` Greg KH
2020-05-15 13:04 ` Vladimir Stankovic
2020-05-29 12:48 ` Pavel Machek [this message]
2020-05-15 12:34 ` [PATCH v6 " Vladimir Stankovic
2020-05-15 12:34 ` [PATCH v6 1/8] usb: Add MA-USB Host kernel module Vladimir Stankovic
2020-05-15 13:01 ` Greg KH
2020-06-11 18:20 ` Vladimir Stankovic
2020-05-15 13:02 ` Greg KH
2020-06-11 18:19 ` [External] " Vladimir Stankovic
2020-05-15 12:34 ` [PATCH v6 2/8] usb: mausb_host: Add link layer implementation Vladimir Stankovic
2020-05-15 12:34 ` [PATCH v6 3/8] usb: mausb_host: HCD initialization Vladimir Stankovic
2020-05-15 13:03 ` Greg KH
2020-06-11 18:19 ` Vladimir Stankovic
2020-05-15 13:07 ` Greg KH
2020-06-11 18:18 ` [External] " Vladimir Stankovic
2020-06-18 8:18 ` Greg KH
2020-05-15 12:34 ` [PATCH v6 4/8] usb: mausb_host: Implement initial hub handlers Vladimir Stankovic
2020-05-15 12:34 ` [PATCH v6 5/8] usb: mausb_host: Introduce PAL processing Vladimir Stankovic
2020-05-15 12:35 ` [PATCH v6 6/8] usb: mausb_host: Add logic for PAL-to-PAL communication Vladimir Stankovic
2020-05-15 12:35 ` [PATCH v6 7/8] usb: mausb_host: MA-USB PAL events processing Vladimir Stankovic
2020-05-15 12:35 ` [PATCH v6 8/8] usb: mausb_host: Process MA-USB data packets Vladimir Stankovic
2020-05-15 13:08 ` [PATCH v6 0/8] Add MA USB Host driver Greg KH
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