From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Sun, 26 Aug 2012 21:30:28 +0200 (CEST) Received: from Chamillionaire.breakpoint.cc ([80.244.247.6]:54465 "EHLO Chamillionaire.breakpoint.cc" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S1903203Ab2HZTaT (ORCPT ); Sun, 26 Aug 2012 21:30:19 +0200 Received: from bigeasy by Chamillionaire.breakpoint.cc with local (Exim 4.72) (envelope-from ) id 1T5iXH-00062S-5X; Sun, 26 Aug 2012 21:30:15 +0200 Date: Sun, 26 Aug 2012 21:30:14 +0200 From: Sebastian Andrzej Siewior To: Kevin Cernekee Cc: Sebastian Andrzej Siewior , balbi@ti.com, ralf@linux-mips.org, stern@rowland.harvard.edu, linux-mips@linux-mips.org, linux-usb@vger.kernel.org Subject: Re: [PATCH V3] usb: gadget: bcm63xx UDC driver Message-ID: <20120826193014.GL3690@breakpoint.cc> References: <5ff8f23aae05690ba89476c4924b9387@localhost> <20120822074815.GB3563@breakpoint.cc> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-archive-position: 34360 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: sebastian@breakpoint.cc Precedence: bulk List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: linux-mips X-List-ID: linux-mips List-subscribe: List-owner: List-post: List-archive: X-list: linux-mips Return-Path: On Sat, Aug 25, 2012 at 12:44:19PM -0700, Kevin Cernekee wrote: > When bcm63xx_udc is in EP0_IN_FAKE_STATUS_PHASE, it won't issue any > more setup() callbacks until the 0-byte reply arrives from the gadget > driver. If the host sends a setup request, the callback will be held > off until after the (unused) status reply. This keeps the gadget > driver from getting confused by out-of-sequence events. Okay. Then it works as requested :) > > - 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? > > Could you please clarify if this is the sequence of events you are describing: > > 1) Host sends a valid SET_CONFIGURATION request to a mass storage gadget > > 2) Hardware instantly auto-acks the request, completing the status > phase and allowing the host to proceed with another ep0 request > > 3) bcm63xx_udc sends a spoofed SET_CONFIGURATION setup packet to the > gadget driver > > 4) setup() callback returns USB_GADGET_DELAYED_STATUS (0x7fff) but > doesn't queue up a reply > > 5) Host sends another setup packet before > usb_composite_setup_continue() is called to send the 0-byte status > reply exactly > If so, the next steps should look like: > > 6) bcm63xx_udc takes a data IRQ, and sets ep0_req_completed > > 7) bcm63xx_udc stays in EP0_IN_FAKE_STATUS_PHASE until the 0-byte > reply is received from usb_composite_setup_continue() > > 8) usb_composite_setup_continue() eventually sends the 0-byte reply > > 9) bcm63xx_udc returns to EP0_IDLE and notices that ep0_req_completed is now set > > 10) bcm63xx_ep0_do_setup() looks at the new request, and performs the > setup() callback for the new setup request Okay. This sounds good. > 11) Data/status phases are handled as usual Please tell you HW vendor that this auto ack feature is complete non sense unless you already have :) Sebastian