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=-3.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 0C0CFC433DF for ; Thu, 27 Aug 2020 14:49:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C139222B4B for ; Thu, 27 Aug 2020 14:49:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=crapouillou.net header.i=@crapouillou.net header.b="OcCw9HFp" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727931AbgH0Osw (ORCPT ); Thu, 27 Aug 2020 10:48:52 -0400 Received: from crapouillou.net ([89.234.176.41]:45044 "EHLO crapouillou.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726887AbgH0N6V (ORCPT ); Thu, 27 Aug 2020 09:58:21 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=crapouillou.net; s=mail; t=1598536659; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=WXO+rgQw15X1NqYEkxv8ngSYDPbmqHU2BHsKBTowoN4=; b=OcCw9HFpgmahQzfbw51wNLZGHul+MmTLwQtu3+zzRCklkZ2RHsqJsEBY+ZOoSR2nGctrxA +xXRh1Ce98O9xsa24PJVNrm7qM0Sm0S6L5VjAQGteHxVhROylf9apICMH5pd3+yBFEDju0 gBq00ke4lZGXH9fw0sQYrVCGcqtrWT0= Date: Thu, 27 Aug 2020 15:50:41 +0200 From: Paul Cercueil Subject: Re: [PATCH 1/1] USB: PHY: JZ4770: Fix uninitialized value written to HW register To: Felipe Balbi Cc: =?UTF-8?b?5ZGo55Cw5p2w?= , =?UTF-8?b?5ZGo5q2j?= , =?UTF-8?b?5ryG6bmP5oyv?= , od@zcrc.me, Greg Kroah-Hartman , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Message-Id: In-Reply-To: <87bliwi5kx.fsf@kernel.org> References: <20200827124308.71963-1-paul@crapouillou.net> <20200827124308.71963-2-paul@crapouillou.net> <87v9h4i6t5.fsf@kernel.org> <87bliwi5kx.fsf@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Le jeu. 27 ao=FBt 2020 =E0 16:25, Felipe Balbi a=20 =E9crit : >=20 > Hi, >=20 > Paul Cercueil writes: >>>> @@ -172,7 +172,8 @@ static int ingenic_usb_phy_init(struct=20 >>>> usb_phy >>>> *phy) >>>> return err; >>>> } >>>>=20 >>>> - priv->soc_info->usb_phy_init(phy); >>>> + reg =3D priv->soc_info->usb_phy_init(phy); >>>> + writel(reg, priv->base + REG_USBPCR_OFFSET); >>>=20 >>> not fixing any bug. >>>=20 >>> Looking at the code, the bug follows after this line. It would=20 >>> suffice >>> to read REG_USBPCR_OFFSET in order to initialize reg. This bug fix >>> could >>> have been a one liner. >>=20 >> There's no need to re-read a register when you have the value=20 >> readily >> available. It just needs to be returned from the usb_phy_init >> callbacks. But yes, it's not a one-liner. >=20 > there's a difference between making a bug fix and reworking the=20 > behavior > of the driver ;-) The one-liner is actually what changes the behavior of the driver,=20 since previously the code did not read back the register. In this case I guess it's fine, because the register does not have=20 volatile bits. >>>> @@ -195,19 +196,15 @@ static void ingenic_usb_phy_remove(void=20 >>>> *phy) >>>> usb_remove_phy(phy); >>>> } >>>>=20 >>>> -static void jz4770_usb_phy_init(struct usb_phy *phy) >>>> +static u32 jz4770_usb_phy_init(struct usb_phy *phy) >>>=20 >>> not a bug fix >>>=20 >>>> { >>>> - struct jz4770_phy *priv =3D phy_to_jz4770_phy(phy); >>>> - u32 reg; >>>> - >>>> - reg =3D USBPCR_AVLD_REG | USBPCR_COMMONONN |=20 >>>> USBPCR_IDPULLUP_ALWAYS >>>> | >>>> + return USBPCR_AVLD_REG | USBPCR_COMMONONN | >>>> USBPCR_IDPULLUP_ALWAYS | >>>> USBPCR_COMPDISTUNE_DFT | USBPCR_OTGTUNE_DFT | >>>> USBPCR_SQRXTUNE_DFT | >>>> USBPCR_TXFSLSTUNE_DFT | USBPCR_TXRISETUNE_DFT | >>>> USBPCR_TXVREFTUNE_DFT | >>>> USBPCR_POR; >>>> - writel(reg, priv->base + REG_USBPCR_OFFSET); >>>=20 >>> not a bug fix >>>=20 >>>> } >>>>=20 >>>> -static void jz4780_usb_phy_init(struct usb_phy *phy) >>>> +static u32 jz4780_usb_phy_init(struct usb_phy *phy) >>>=20 >>> not a bug fix >>>=20 >>>> @@ -216,11 +213,10 @@ static void jz4780_usb_phy_init(struct >>>> usb_phy *phy) >>>> USBPCR1_WORD_IF_16BIT; >>>> writel(reg, priv->base + REG_USBPCR1_OFFSET); >>>>=20 >>>> - reg =3D USBPCR_TXPREEMPHTUNE | USBPCR_COMMONONN | USBPCR_POR; >>>> - writel(reg, priv->base + REG_USBPCR_OFFSET); >>>> + return USBPCR_TXPREEMPHTUNE | USBPCR_COMMONONN | USBPCR_POR; >>>=20 >>> not a bug fix >>>=20 >>>> } >>>>=20 >>>> -static void x1000_usb_phy_init(struct usb_phy *phy) >>>> +static u32 x1000_usb_phy_init(struct usb_phy *phy) >>>=20 >>> not a bug fix >>>=20 >>>> { >>>> struct jz4770_phy *priv =3D phy_to_jz4770_phy(phy); >>>> u32 reg; >>>> @@ -228,13 +224,12 @@ static void x1000_usb_phy_init(struct=20 >>>> usb_phy >>>> *phy) >>>> reg =3D readl(priv->base + REG_USBPCR1_OFFSET) | >>>> USBPCR1_WORD_IF_16BIT; >>>> writel(reg, priv->base + REG_USBPCR1_OFFSET); >>>>=20 >>>> - reg =3D USBPCR_SQRXTUNE_DCR_20PCT | USBPCR_TXPREEMPHTUNE | >>>> + return USBPCR_SQRXTUNE_DCR_20PCT | USBPCR_TXPREEMPHTUNE | >>>> USBPCR_TXHSXVTUNE_DCR_15MV | USBPCR_TXVREFTUNE_INC_25PPT | >>>> USBPCR_COMMONONN | USBPCR_POR; >>>> - writel(reg, priv->base + REG_USBPCR_OFFSET); >>>=20 >>> not a bug fix >>>=20 >>>> } >>>>=20 >>>> -static void x1830_usb_phy_init(struct usb_phy *phy) >>>> +static u32 x1830_usb_phy_init(struct usb_phy *phy) >>>=20 >>> not a bug fix >>>=20 >>>> { >>>> struct jz4770_phy *priv =3D phy_to_jz4770_phy(phy); >>>> u32 reg; >>>> @@ -246,9 +241,8 @@ static void x1830_usb_phy_init(struct usb_phy >>>> *phy) >>>> USBPCR1_DMPD | USBPCR1_DPPD; >>>> writel(reg, priv->base + REG_USBPCR1_OFFSET); >>>>=20 >>>> - reg =3D USBPCR_IDPULLUP_OTG | USBPCR_VBUSVLDEXT >>>> | USBPCR_TXPREEMPHTUNE | >>>> + return USBPCR_IDPULLUP_OTG | USBPCR_VBUSVLDEXT | >>>> USBPCR_TXPREEMPHTUNE | >>>> USBPCR_COMMONONN | USBPCR_POR; >>>> - writel(reg, priv->base + REG_USBPCR_OFFSET); >>>=20 >>> not a bug fix >>=20 >> Well, if you don't like my bug fix, next time wait for my=20 >> Reviewed-by. >=20 > why so angry? Take a break every once in a while. Besides, someone=20 > else > already sent the oneliner before you ;-) I'm just pissed that this patch has not been tested. I don't like=20 sloppy work. > In any case, why should I wait for your Reviewed-by? Get maintainer > doesn't list you as the maintainer for it. Do you want to update > MAINTAINERS by any chance? Yes, I thought I was (I'm maintainer of all Ingenic drivers), that also=20 explains why I wasn't Cc'd for the oneliner patch you mentioned... IIRC Zhou has a patch to move the driver to drivers/phy/, I'll add=20 myself as maintainer once it's moved there. -Paul