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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 87218C4332F for ; Thu, 30 Dec 2021 14:12:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239842AbhL3OMe (ORCPT ); Thu, 30 Dec 2021 09:12:34 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35584 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233197AbhL3OMd (ORCPT ); Thu, 30 Dec 2021 09:12:33 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B5419C061574; Thu, 30 Dec 2021 06:12:32 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 71743B81A71; Thu, 30 Dec 2021 14:12:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7CE00C36AE9; Thu, 30 Dec 2021 14:12:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1640873550; bh=SDWGmvyOLn/L+pfvPdM1ycMOLuAZBXHTBvkwnICj4/o=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=PM61r4weOAsYUmXoK4aXG8XNsAutO+GTIRxJJe8zrY/3+scY8//HZupJWmNPCynIr zHQygi62PrPjJmASmo8CxDPoMxX+qtNot2GX4JzVH78UDW1W6Ue5KEjlHhc4vEM78u TiZiumAtaRilKJW7luqYdycRKdHREo6P1GBMMKzY= Date: Thu, 30 Dec 2021 15:12:27 +0100 From: Greg Kroah-Hartman To: Yaqin Pan Cc: Rob Herring , Felipe Balbi , linux-usb@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, kernel@vivo.com Subject: Re: [PATCH v3 1/2] usb: dwc3: Add a quirk to set GUCTL.SPRSCTRLTRANSEN bit. Message-ID: References: <20211230135832.23005-1-akingchen@vivo.com> <20211230135832.23005-2-akingchen@vivo.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211230135832.23005-2-akingchen@vivo.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Dec 30, 2021 at 09:58:30PM +0800, Yaqin Pan wrote: > This quirk is only for dwc3 host mode. > the dwc3 controller can't emurate some devices successfully. > For example, TF card reader (aaaa:8816): > failed log > usb 1-1: new high-speed USB device number 2 using xhci-hcd > usb 1-1: device descriptor read/all, error -110 > >From the usb analyzer, always return NAK in the data phase. > if enable the GUCTL.SPRSCTRLTRANSEN bit. then the log is: > usb 2-1: new high-speed USB device number 3 using xhci-hcd > usb 2-1: New USB device found, idVendor=aaaa, > idProduct=8816, bcdDevice=13.08 > usb 2-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3 > usb 2-1: Product: MXT USB Device > usb 2-1: Manufacturer: MXTronics > usb 2-1: SerialNumber: 150101v01 > usb 2-1: New USB device found, VID=aaaa, PID=8816 > > Some devices are slow in responding to Control transfers. > Scheduling mulitiple transactions in one microframe/frame > can cause the devices to misbehave. if this qurik is enabled, > the host controller schedules transations for a Control transfer > in defferent microframes/frame. If this is needed for all devices (i.e. you do not know what device is going to be plugged in), why not just enable it for all controllers? Why whould you NOT want this enabled? Or is this a broken hardware device and only specific host controllers need this? If so, how do we know which ones need this set and which do not? thanks, greg k-h