From mboxrd@z Thu Jan  1 00:00:00 1970
From: Ben Hutchings <bhutchings@solarflare.com>
Subject: Re: [PATCH 1/1] TX throttling bug-fixing patch of AX88179_178A
Date: Thu, 25 Jul 2013 16:00:35 +0100
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Cc: Eric Dumazet <eric.dumazet@gmail.com>,
	Oliver Neukum <oliver@neukum.org>,
	Grant Grundler <grundler@google.com>,
	Freddy Xin <freddy@asix.com.tw>,
	David Miller <davem@davemloft.net>,
	netdev <netdev@vger.kernel.org>, <linux-usb@vger.kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	ASIX Louis =?UTF-8?Q?=5B=E8=98=87=E5=A8=81=E9=99=B8=5D?=
	<louis@asix.com.tw>, "Allan Chou" <allan@asix.com.tw>
To: Ming Lei <tom.leiming@gmail.com>
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On Thu, 2013-07-25 at 22:52 +0800, Ming Lei wrote:
[...]
> On Thu, Jul 25, 2013 at 9:34 PM, Ben Hutchings
> <bhutchings@solarflare.com> wrote:
> >
> > Not that I have any experience with USB drivers, but perhaps
> > usb_sg_init()?
> 
> USB SG library doesn't support submitting SG URB asynchronously, but that isn't
> a big deal.  The problem is that many USB host controllers can't build
> one single
> packet from two buffers, what is why USB stack requires size of all
> buffers(except
> for last one) in sg list can be divided by max endpoint packet
> size.(1024 for usbnet)

Ugh.  Maybe the USB stack should allow drivers to find out about and
take advantage of a more flexible host controller.  Sounds like it could
be a big job, though.

Ben. (glad not to be using any USB net devices)

-- 
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.