From: Felipe Balbi <felipe.balbi@linux.intel.com>
To: Alan Stern <stern@rowland.harvard.edu>,
Andrey Konovalov <andreyknvl@google.com>
Cc: USB list <linux-usb@vger.kernel.org>,
Alexander Potapenko <glider@google.com>,
Dmitry Vyukov <dvyukov@google.com>
Subject: Re: Pass transfer_buffer to gadget drivers
Date: Wed, 19 Jun 2019 09:36:47 +0300 [thread overview]
Message-ID: <874l4mf5ds.fsf@linux.intel.com> (raw)
In-Reply-To: <Pine.LNX.4.44L0.1906180948100.1659-100000@iolanthe.rowland.org>
[-- Attachment #1: Type: text/plain, Size: 855 bytes --]
Hi,
Alan Stern <stern@rowland.harvard.edu> writes:
>> Also, does the gadget subsystem guarantee, that we get the complete()
>> callback for the DATA stage of the OUT control request before we get a
>> setup() callback for the next control request if there's any?
>
> As I recall, this isn't mentioned in the documentation. But the UDC
> drivers I know of do behave that way, and it's reasonable to assume
> they all do.
>
> After all, a data-stage transfer can't complete _after_ the next Setup
> packet arrives. Reception of a new Setup packet invalidates all
> ongoing control transfers.
Considering that the gadget API handles one stage at a time, it would be
impossible for this to not be the case :-)
UDCs start a trasnfer only for the setup phase, then process the
control request to decide what to do next.
--
balbi
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 832 bytes --]
next prev parent reply other threads:[~2019-06-19 6:36 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-07 11:44 Pass transfer_buffer to gadget drivers Andrey Konovalov
2019-06-07 12:02 ` Felipe Balbi
2019-06-07 12:14 ` Andrey Konovalov
2019-06-07 12:25 ` Felipe Balbi
2019-06-07 12:32 ` Andrey Konovalov
2019-06-07 12:43 ` Felipe Balbi
2019-06-07 12:45 ` Andrey Konovalov
2019-06-07 14:04 ` Alan Stern
2019-06-07 14:38 ` Andrey Konovalov
2019-06-07 15:02 ` Alan Stern
2019-06-07 15:05 ` Andrey Konovalov
2019-06-18 13:31 ` Andrey Konovalov
2019-06-18 13:34 ` Andrey Konovalov
2019-06-18 13:53 ` Alan Stern
2019-06-19 6:36 ` Felipe Balbi [this message]
2019-06-28 16:44 ` Andrey Konovalov
2019-06-28 17:29 ` Andrey Konovalov
2019-06-28 18:07 ` Alan Stern
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=874l4mf5ds.fsf@linux.intel.com \
--to=felipe.balbi@linux.intel.com \
--cc=andreyknvl@google.com \
--cc=dvyukov@google.com \
--cc=glider@google.com \
--cc=linux-usb@vger.kernel.org \
--cc=stern@rowland.harvard.edu \
/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.