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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 autolearn=no 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 5A5D8C3A59D for ; Thu, 22 Aug 2019 05:14:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1DCB621848 for ; Thu, 22 Aug 2019 05:14:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728886AbfHVFOy (ORCPT ); Thu, 22 Aug 2019 01:14:54 -0400 Received: from gate.crashing.org ([63.228.1.57]:55349 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727781AbfHVFOy (ORCPT ); Thu, 22 Aug 2019 01:14:54 -0400 Received: from localhost (localhost.localdomain [127.0.0.1]) by gate.crashing.org (8.14.1/8.14.1) with ESMTP id x7M5EeLF023357; Thu, 22 Aug 2019 00:14:41 -0500 Message-ID: <4c8a9941fb54dffd823335c9f4bc01f3158fb1d5.camel@kernel.crashing.org> Subject: Re: f_mass_storage vs drivers/target From: Benjamin Herrenschmidt To: Alan Stern Cc: USB list , Sebastian Andrzej Siewior Date: Thu, 22 Aug 2019 15:14:39 +1000 In-Reply-To: References: <9c7090713374e80b6c26a9dabb753c5b35b9c93d.camel@kernel.crashing.org> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.5-0ubuntu0.18.04.1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Thu, 2019-08-22 at 14:58 +1000, Benjamin Herrenschmidt wrote: > > Ah lovely ... the 338x fails in EP autoconf with f_tcm, digging... > > While digging I found this gem: > > /* USB3380: use same address for usb and hardware endpoints */ > snprintf(name, sizeof(name), "ep%d%s", usb_endpoint_num(desc), > usb_endpoint_dir_in(desc) ? "in" : "out"); > ep = gadget_find_ep_by_name(_gadget, name); > if (ep && usb_gadget_ep_match_desc(_gadget, ep, desc, ep_comp)) > return ep; > > Any idea what's that supposed to achieve ? > > When ep_match is called, usb_endpoint_num() hasn't been set yet so > it's always 0 and always fails... or am I missing something ? Two problems: - net2280.c doesn't set a max EP size, so autoconfig fails since f_tcm specifies one. What about this ? --- a/drivers/usb/gadget/udc/core.c +++ b/drivers/usb/gadget/udc/core.c @@ -940,12 +940,14 @@ int usb_gadget_ep_match_desc(struct usb_gadget *gadget, if (usb_endpoint_dir_out(desc) && !ep->caps.dir_out) return 0; - if (max > ep->maxpacket_limit) + if (ep->maxpacket_limit && max > ep->maxpacket_limit) return 0; (ie assume that ep->maxpacket_limit 0 means the UDC supports any legal size) - No UDC driver other than dummy sets max_streams, and f_tcm requires 4, so f_tcm will fail with *any* superspeed UDC driver as far as I can tell. Was it ever tested with USB 3 ? I'm not sure what the right fix here yet is as I yet have to learn about what those USB3 streams are :-) For now I've commented things out. It's still not working yet as configuring f_tcm seems to be a black art with no useful documentation or examples anywhere (the device shows up on the host but doesn't bind to any mass storage driver ... yet). Cheers, Ben.