From: Oliver Neukum <oneukum@suse.com>
To: Alan Stern <stern@rowland.harvard.edu>
Cc: David Laight <David.Laight@ACULAB.COM>,
"gregKH@linuxfoundation.org" <gregKH@linuxfoundation.org>,
"linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>
Subject: UAS: fix alignment of scatter/gather segments
Date: Mon, 29 Apr 2019 18:58:50 +0200 [thread overview]
Message-ID: <1556557130.20085.24.camel@suse.com> (raw)
On Mo, 2019-04-29 at 12:08 -0400, Alan Stern wrote:
> On Mon, 29 Apr 2019, Oliver Neukum wrote:
>
> > On Mo, 2019-04-29 at 15:06 +0000, David Laight wrote:
>
> > But the statement the old comment made are no longer correct.
>
> Perhaps David would be satisfied if the comment were changed to say
> that _some_ USB controller drivers have this unusual alignment
> requirement.
It would seem to me that every controller that does not do
scatter/gather has this requirement. In other words, this is
the true requirement of USB. It does not come from the
controller. It comes from the protocol's need to not
send a short package.
The second, old, comment is about controllers.
Regards
Oliver
WARNING: multiple messages have this Message-ID (diff)
From: Oliver Neukum <oneukum@suse.com>
To: Alan Stern <stern@rowland.harvard.edu>
Cc: David Laight <David.Laight@ACULAB.COM>,
"gregKH@linuxfoundation.org" <gregKH@linuxfoundation.org>,
"linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>
Subject: Re: [PATCH] UAS: fix alignment of scatter/gather segments
Date: Mon, 29 Apr 2019 18:58:50 +0200 [thread overview]
Message-ID: <1556557130.20085.24.camel@suse.com> (raw)
Message-ID: <20190429165850.lJi1I6d1n0fghwvupKim8OQ57e9OLiORARWNOniUx4I@z> (raw)
In-Reply-To: <Pine.LNX.4.44L0.1904291207300.1632-100000@iolanthe.rowland.org>
On Mo, 2019-04-29 at 12:08 -0400, Alan Stern wrote:
> On Mon, 29 Apr 2019, Oliver Neukum wrote:
>
> > On Mo, 2019-04-29 at 15:06 +0000, David Laight wrote:
>
> > But the statement the old comment made are no longer correct.
>
> Perhaps David would be satisfied if the comment were changed to say
> that _some_ USB controller drivers have this unusual alignment
> requirement.
It would seem to me that every controller that does not do
scatter/gather has this requirement. In other words, this is
the true requirement of USB. It does not come from the
controller. It comes from the protocol's need to not
send a short package.
The second, old, comment is about controllers.
Regards
Oliver
next prev reply other threads:[~2019-04-29 16:58 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-29 12:20 UAS: fix alignment of scatter/gather segments Oliver Neukum
2019-04-29 12:20 ` [PATCH] " Oliver Neukum
2019-04-29 13:31 ` David Laight
2019-04-29 13:31 ` [PATCH] " David Laight
2019-04-29 13:38 ` Oliver Neukum
2019-04-29 13:38 ` [PATCH] " Oliver Neukum
2019-04-29 14:19 ` David Laight
2019-04-29 14:19 ` [PATCH] " David Laight
2019-04-29 14:32 ` Oliver Neukum
2019-04-29 14:32 ` [PATCH] " Oliver Neukum
2019-04-29 15:06 ` David Laight
2019-04-29 15:06 ` [PATCH] " David Laight
2019-04-29 15:57 ` Oliver Neukum
2019-04-29 15:57 ` [PATCH] " Oliver Neukum
2019-04-29 16:08 ` Alan Stern
2019-04-29 16:08 ` [PATCH] " Alan Stern
2019-04-29 16:58 ` Oliver Neukum [this message]
2019-04-29 16:58 ` Oliver Neukum
2019-04-29 17:55 ` Alan Stern
2019-04-29 17:55 ` [PATCH] " Alan Stern
2019-04-29 18:42 ` Oliver Neukum
2019-04-29 18:42 ` [PATCH] " Oliver Neukum
2019-04-29 19:42 ` Alan Stern
2019-04-29 19:42 ` [PATCH] " Alan Stern
2019-04-30 9:16 ` David Laight
2019-04-30 9:16 ` [PATCH] " David Laight
2019-04-30 14:39 ` Alan Stern
2019-04-30 14:39 ` [PATCH] " Alan Stern
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