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 41097C7EE2C for ; Mon, 29 May 2023 19:01:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229671AbjE2TBK (ORCPT ); Mon, 29 May 2023 15:01:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47904 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229576AbjE2TBI (ORCPT ); Mon, 29 May 2023 15:01:08 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AE838BE; Mon, 29 May 2023 12:01:07 -0700 (PDT) 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 dfw.source.kernel.org (Postfix) with ESMTPS id 427F461CF2; Mon, 29 May 2023 19:01:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4CDD4C433D2; Mon, 29 May 2023 19:01:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1685386866; bh=T+5R6lxbnuo+r+DOxgiHvINIJHvsFc4xC+EMiDuzDTc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=W5TU1hUnj0wtvHQYLnOTZtlxCUwEWu7kG/96xchiAr4xX11dj9Icqw7QfVhOMF6Sa RNfnyRjwxT6YL2pi1eVsCcIMd5DtBPp5h9HzONwPiUjHrhREwM8O1VI9b+2ZOWiMjB MR8oWsGTJToppTAMuEl4Aha3dM/mUDl8/MvG2kFc= Date: Mon, 29 May 2023 20:01:03 +0100 From: Greg Kroah-Hartman To: Prashanth K Cc: Matthias Brugger , AngeloGioacchino Del Regno , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v5] usb: common: usb-conn-gpio: Set last role to unknown before initial detection Message-ID: <2023052943-headfirst-satchel-6d90@gregkh> References: <1685004825-30157-1-git-send-email-quic_prashk@quicinc.com> <2023052513-gestate-tartar-bf15@gregkh> <5f144d80-0439-d014-c845-1cfb1adb840a@quicinc.com> <2023052801-immersion-venus-ad0f@gregkh> 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-kernel@vger.kernel.org On Tue, May 30, 2023 at 12:00:15AM +0530, Prashanth K wrote: > > > On 28-05-23 05:03 pm, Greg Kroah-Hartman wrote: > > > > > diff --git a/drivers/usb/common/usb-conn-gpio.c b/drivers/usb/common/usb-conn-gpio.c > > > > > index e20874c..30bdb81 100644 > > > > > --- a/drivers/usb/common/usb-conn-gpio.c > > > > > +++ b/drivers/usb/common/usb-conn-gpio.c > > > > > @@ -257,6 +257,9 @@ static int usb_conn_probe(struct platform_device *pdev) > > > > > platform_set_drvdata(pdev, info); > > > > > device_set_wakeup_capable(&pdev->dev, true); > > > > > + /* Set last role to unknown before performing the initial detection */ > > > > > + info->last_role = USB_ROLE_UNKNOWN; > > > > > > > > Shouldn't last_role have already been set to 0? If so, why not just > > > > have this enum value be 0? > > > Last role would be 0 during first detection, that's the problem here. > > > During initial detection, if the the new role is detected as USB_ROLE_NONE > > > (0), then we wouldn't call the set_role(). But it should send the current > > > role to gadget after the inital detection. > > > > So you are hoping that the old enum type is still assigned to 0? That's > > brave, please make it explicit otherwise it's very hard to follow or > > ensure that this really will happen. And most of all, document it so > > that that value remains 0 in the future, otherwise a list of enum types > > without explicit values are seen as if the values do not matter. > > > > thanks, > > > > greg k-h > > So I think it would be better to add USB_ROLE_UNKNOWN towards the end of > enum usb_role, so that we can avoid explicit declaration. Is that fine? > > enum usb_role { > USB_ROLE_NONE, > USB_ROLE_HOST, > USB_ROLE_DEVICE, > + USB_ROLE_UNKNOWN, Either is fine, be explicit, or not, just don't mix the two please. thanks, greg k-h