linux-mips
[Top] [All Lists]

Re: [PATCH V3] usb: gadget: bcm63xx UDC driver

To: Kevin Cernekee <cernekee@gmail.com>
Subject: Re: [PATCH V3] usb: gadget: bcm63xx UDC driver
From: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Date: Wed, 22 Aug 2012 09:48:15 +0200
Cc: balbi@ti.com, ralf@linux-mips.org, sebastian@breakpoint.cc, stern@rowland.harvard.edu, linux-mips@linux-mips.org, linux-usb@vger.kernel.org
In-reply-to: <5ff8f23aae05690ba89476c4924b9387@localhost>
List-archive: <http://www.linux-mips.org/archives/linux-mips/>
List-help: <mailto:ecartis@linux-mips.org?Subject=help>
List-id: linux-mips <linux-mips.eddie.linux-mips.org>
List-owner: <mailto:ralf@linux-mips.org>
List-post: <mailto:linux-mips@linux-mips.org>
List-software: Ecartis version 1.0.0
List-subscribe: <mailto:ecartis@linux-mips.org?subject=subscribe%20linux-mips>
List-unsubscribe: <mailto:ecartis@linux-mips.org?subject=unsubscribe%20linux-mips>
References: <5ff8f23aae05690ba89476c4924b9387@localhost>
Sender: linux-mips-bounce@linux-mips.org
User-agent: Mutt/1.5.21 (2010-09-15)
On Tue, Aug 21, 2012 at 06:22:35PM -0700, Kevin Cernekee wrote:

Just one thing that bit while I was sleeping:
The HW acks SetConfig on its own. Once you notice this, you set
->ep0_req_set_cfg and set state in bcm63xx_ep0_do_idle() to
EP0_IN_FAKE_STATUS_PHASE. This is I guess the workaround for mass_storage's
hold with DELAYED_STATUS and continues with a zero packet.
Now two questions:
- If a gadget descides not NAK / stall the SetConfig requests. What happens
  here?
- What happens if the host is faster than the UDC. SetConfig returns in
  usb-storage with "DELAYED_STATUS". HW Acks this. Could the Host send another
  request before the gadget queues the ep0 request?

Sebastian

<Prev in Thread] Current Thread [Next in Thread>