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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 5F44CC433DF for ; Mon, 19 Oct 2020 13:36:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 04C02222C3 for ; Mon, 19 Oct 2020 13:36:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727893AbgJSNgL (ORCPT ); Mon, 19 Oct 2020 09:36:11 -0400 Received: from mga11.intel.com ([192.55.52.93]:1543 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727297AbgJSNgL (ORCPT ); Mon, 19 Oct 2020 09:36:11 -0400 IronPort-SDR: aUXDBMHqHsfeQJWE4jsBbwO4QchpG+HdXueYsI/ziV35pDjqfBDUJWeaZkpMIoO1K+0Rl4Zqwb UgBNXjkeCZeQ== X-IronPort-AV: E=McAfee;i="6000,8403,9778"; a="163543497" X-IronPort-AV: E=Sophos;i="5.77,394,1596524400"; d="scan'208";a="163543497" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Oct 2020 06:36:09 -0700 IronPort-SDR: DEDioaHQNQfGihUOZ2WZ6kdJ6QOT0PkV5nBkfI5GgCGodfqUcPmU+cmCtGOVJ9HSEdy4kQL/eR 11TG78iD4vIg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.77,394,1596524400"; d="scan'208";a="422182289" Received: from kuha.fi.intel.com ([10.237.72.162]) by fmsmga001.fm.intel.com with SMTP; 19 Oct 2020 06:36:08 -0700 Received: by kuha.fi.intel.com (sSMTP sendmail emulation); Mon, 19 Oct 2020 16:36:07 +0300 Date: Mon, 19 Oct 2020 16:36:07 +0300 From: Heikki Krogerus To: "Dmitry N. Mikushin" Cc: linux-usb@vger.kernel.org Subject: Re: Any example of USB gadget for DRD device mode on Intel Gemini Lake? Message-ID: <20201019133607.GC1667571@kuha.fi.intel.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Mon, Oct 19, 2020 at 01:27:35PM +0200, Dmitry N. Mikushin wrote: > Dear All, > > I'm confused by the USB gadget mode on the recent Intel SoCs, such as > Gemini Lake. The /sys/class/udc is empty, and a SoC can't present > itself as a IoT gadget this way, yet definitely being designed as > such. I've noticed the concept of dual-role-device, which seems to > replace the OTG. Particularly, Harry Pan mentioned that Gemini Lake > supports DRD in port 0. So do you have the dwc3 (the USB device controller) PCI device available/visible on your system? What do you get if you run: lspci -nn|grep USB The DWC3 PCI device ID on Gemini lake is 0x31aa (search PCI_DEVICE_ID_INTEL_GLK in drivers/usb/dwc3/dwc3-pci.c). Which board/product are you using. Which kernel are you using? Is the dwc3 driver enabled in your kernel? Which gadget are you testing with? g_zero? thanks, -- heikki