From patchwork Wed Dec 19 09:26:45 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Elder X-Patchwork-Id: 10736943 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C733B13AD for ; Wed, 19 Dec 2018 09:27:25 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B42D52A5F0 for ; Wed, 19 Dec 2018 09:27:25 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A84982ABC6; Wed, 19 Dec 2018 09:27:25 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 338232A5F0 for ; Wed, 19 Dec 2018 09:27:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728795AbeLSJ1N (ORCPT ); Wed, 19 Dec 2018 04:27:13 -0500 Received: from perceval.ideasonboard.com ([213.167.242.64]:38824 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728773AbeLSJ1L (ORCPT ); Wed, 19 Dec 2018 04:27:11 -0500 Received: from localhost.localdomain (unknown [96.44.9.229]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 9CE3F579; Wed, 19 Dec 2018 10:27:07 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1545211628; bh=4vJ0j2F6OAiHvv4VEVlOuG6MO6g3tnFNmuDZjqubpQk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fmla7vimncgraEDEcpz8s9DxZrGZAbmP7w3RZEyg+XF6CkTeZRAcXuyJv2pClsWPD 5eBjIuJbmV2IH41WAG85iVAqqXdYQUmEVTWxbHXuD4VU3fBHzX+g84BrM032k9X9r6 gFz5sm3GHRgmi4BxY2NZQcMzUukkIGk6OW6O7Xcs= From: Paul Elder To: laurent.pinchart@ideasonboard.com, kieran.bingham@ideasonboard.com Cc: Paul Elder , b-liu@ti.com, stern@rowland.harvard.edu, rogerq@ti.com, balbi@kernel.org, gregkh@linuxfoundation.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 4/6] usb: gadget: add mechanism to specify an explicit status stage Date: Wed, 19 Dec 2018 04:26:45 -0500 Message-Id: <20181219092647.12397-5-paul.elder@ideasonboard.com> X-Mailer: git-send-email 2.19.2 In-Reply-To: <20181219092647.12397-1-paul.elder@ideasonboard.com> References: <20181219092647.12397-1-paul.elder@ideasonboard.com> MIME-Version: 1.0 Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP A usb gadget function driver may or may not want to delay the status stage of a control OUT request. An instance 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 after calling usb_gadget_giveback_request. The status of the request that was just given back must be fed into usb_gadget_control_complete. To support the explicit status stage, it might then check what stage the usb_request was queued in, and send an ACK. Signed-off-by: Paul Elder v1 Reviewed-by: Laurent Pinchart Acked-by: Alan Stern --- Changes from v2: Add status parameter to usb_gadget_control_complete, so that a usb_request is not queued if the status of the just given back request is nonzero. Changes from v1: Complete change of API. Now we use a flag that should be set in the usb_request that is queued for the data stage to signal to the UDC that we want to delay the status stage (as opposed to setting a flag in the UDC itself, that persists across all requests). We now also provide a function for UDC drivers to very easily allow implicit status stages, to mitigate the need to convert all function drivers to this new API at once, and to make it easier for UDC drivers to convert. drivers/usb/gadget/udc/core.c | 34 ++++++++++++++++++++++++++++++++++ include/linux/usb/gadget.h | 10 ++++++++++ 2 files changed, 44 insertions(+) diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c index af88b48c1cea..0a0ccd2b7639 100644 --- a/drivers/usb/gadget/udc/core.c +++ b/drivers/usb/gadget/udc/core.c @@ -894,6 +894,40 @@ EXPORT_SYMBOL_GPL(usb_gadget_giveback_request); /* ------------------------------------------------------------------------- */ +/** + * usb_gadget_control_complete - complete the status stage of a control + * request, or delay it + * Context: in_interrupt() + * + * @gadget: gadget whose control request's status stage should be completed + * @explicit_status: true to delay status stage, false to complete here + * @status: completion code of previously completed request + * + * This is called by device controller drivers after returning the completed + * request back to the gadget layer, to either complete or delay the status + * stage. + */ +void usb_gadget_control_complete(struct usb_gadget *gadget, + unsigned int explicit_status, int status) +{ + struct usb_request *req; + + if (explicit_status || status) + return; + + /* Send an implicit status-stage request for ep0 */ + req = usb_ep_alloc_request(gadget->ep0, GFP_ATOMIC); + if (req) { + req->length = 0; + req->explicit_status = 0; + req->complete = usb_ep_free_request; + usb_ep_queue(gadget->ep0, req, GFP_ATOMIC); + } +} +EXPORT_SYMBOL_GPL(usb_gadget_control_complete); + +/* ------------------------------------------------------------------------- */ + /** * gadget_find_ep_by_name - returns ep whose name is the same as sting passed * in second parameter or NULL if searched endpoint not found diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h index e5cd84a0f84a..1e3a23637468 100644 --- a/include/linux/usb/gadget.h +++ b/include/linux/usb/gadget.h @@ -73,6 +73,7 @@ struct usb_ep; * Note that for writes (IN transfers) some data bytes may still * reside in a device-side FIFO when the request is reported as * complete. + * @explicit_status: If true, delays the status stage * * These are allocated/freed through the endpoint they're used with. The * hardware's driver can add extra per-request data to the memory it returns, @@ -114,6 +115,8 @@ struct usb_request { int status; unsigned actual; + + unsigned explicit_status:1; }; /*-------------------------------------------------------------------------*/ @@ -850,6 +853,13 @@ extern void usb_gadget_giveback_request(struct usb_ep *ep, /*-------------------------------------------------------------------------*/ +/* utility to complete or delay status stage */ + +void usb_gadget_control_complete(struct usb_gadget *gadget, + unsigned int explicit_status, int status); + +/*-------------------------------------------------------------------------*/ + /* utility to find endpoint by name */ extern struct usb_ep *gadget_find_ep_by_name(struct usb_gadget *g,