From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E3F6DC43387 for ; Fri, 11 Jan 2019 08:23:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B3C2A20656 for ; Fri, 11 Jan 2019 08:23:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="lArhwKKS" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730105AbfAKIXv (ORCPT ); Fri, 11 Jan 2019 03:23:51 -0500 Received: from perceval.ideasonboard.com ([213.167.242.64]:60412 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728682AbfAKIXv (ORCPT ); Fri, 11 Jan 2019 03:23:51 -0500 Received: from localhost.localdomain (unknown [96.44.9.117]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 947B8547; Fri, 11 Jan 2019 09:23:47 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1547195028; bh=bEB1oYi+scrgN1ZJyJRgkEbLbXQItSsxMVr+gMQfUgQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=lArhwKKSHe6KwBEednGNsaGZQxO7fnoZFjj2RS8eTd8zzHwKhAwr+/weF/33OD8Co Rqc0wbQ2QcAt5wRHvpD7u8wdm1T9g0bvYYejiP+YEQSvUM7y5trdEHGgksX24N2edK idMWT8wj1DAb4TtdQjDJT855wk+2RZXNuSxRN8Eg= Date: Fri, 11 Jan 2019 03:23:40 -0500 From: Paul Elder To: Alan Stern Cc: laurent.pinchart@ideasonboard.com, kieran.bingham@ideasonboard.com, b-liu@ti.com, rogerq@ti.com, balbi@kernel.org, gregkh@linuxfoundation.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v5 4/6] usb: gadget: add mechanism to specify an explicit status stage Message-ID: <20190111082340.GB32268@localhost.localdomain> References: <20190109070856.27460-5-paul.elder@ideasonboard.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 09, 2019 at 02:06:31PM -0500, Alan Stern wrote: > On Wed, 9 Jan 2019, Paul Elder wrote: > > > A usb gadget function driver may or may not want to delay the status > > stage of a control OUT request. An instance where it might want to is to > > asynchronously validate the data of a class-specific request. > > > > A function driver that wants an explicit status stage should set the > > newly added explicit_status flag of the usb_request corresponding to the > > data stage. Later on, the function driver can explicitly complete the > > status stage by enqueueing a usb_request for ACK, or calling > > usb_ep_set_halt() for STALL. > > > > To support both explicit and implicit status stages, a UDC driver must > > call the newly added usb_gadget_control_complete function right before > > calling usb_gadget_giveback_request. To support the explicit status > > stage, it might then check what stage the usb_request was queued in, and > > for control IN ACK the host's zero-length data packet, or for control > > OUT send a zero-length DATA1 ACK packet. > > > > Signed-off-by: Paul Elder > > v4 Acked-by: Alan Stern > > v1 Reviewed-by: Laurent Pinchart > > This looks good and has passed my tests so far. Good! Thank you :) > Can you check your uvc > changes using dummy_hcd with the patch below? I'm not sure what to make of the test results. I get the same results with or without the patch. Which I guess makes sense... in dummy_queue, this is getting hit when the uvc function driver tries to complete the delayed status: req = usb_request_to_dummy_request(_req); if (!_req || !list_empty(&req->queue) || !_req->complete) return -EINVAL; So the delayed/explicit status stage is never completed, afaict. Paul