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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F0F11C433EF for ; Tue, 16 Nov 2021 00:09:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D344D61263 for ; Tue, 16 Nov 2021 00:09:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347364AbhKPAMB (ORCPT ); Mon, 15 Nov 2021 19:12:01 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59500 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347333AbhKOVHy (ORCPT ); Mon, 15 Nov 2021 16:07:54 -0500 Received: from mail-wm1-x32f.google.com (mail-wm1-x32f.google.com [IPv6:2a00:1450:4864:20::32f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D02A3C0432DC for ; Mon, 15 Nov 2021 12:56:26 -0800 (PST) Received: by mail-wm1-x32f.google.com with SMTP id r9-20020a7bc089000000b00332f4abf43fso593382wmh.0 for ; Mon, 15 Nov 2021 12:56:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=broadcom.com; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=UrTT5OjFF/ppB+7IkG4hoMbeGHcKoOd9F+xHAZ+mnyo=; b=f7wjwIB/WhAldwlcCPBWND3Iq9q35SWJbzttX4G4tLxXYUVT7O+6uICXS4XN2fTJwt t0P76Pua0+3okKElXWZkrUKwUEluSn0JLOHBpcRxUNAdhr9x6B+qaLXBHvcNUNXwRBeq IMPA9YhnPqyh23tr+6MYSb1xrGxvBcWnMrpSU= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=UrTT5OjFF/ppB+7IkG4hoMbeGHcKoOd9F+xHAZ+mnyo=; b=Ryw0hDFrZbFl4ql09cl5grj94XAw5jl+dZrzzsHX0Af1+UDUQfeHrFXjzs3tmZMPzI vZnH3GpcRMU4QVRiaBeDUiKGNJTwZCpjWVbXbrIU3wFmOfwLG/tD6U/GLtI3cgM8dEBi GAtUekaXhFKDhnYC2D6OcoM0fpdPJHSc2JkGuNoZGFKODzS7gIIs4zpHZiUIvt1qQSgF bIw/WVh5GD8hsV9rm8HRoNO0orR+XXtR8CRpPy9ybt98yZC/KNY+9H+ufAwnXimBUXhi xuhy2DN3uKfc6aolBov9Q0rngnrIONRyP95M2IrjcPjq9GytdXU2GlkZhdVVQD1NA+qX zy8A== X-Gm-Message-State: AOAM530te0RtTDJbng4suUpQqdq+5SDzzwt2W85RaqGe4GAFQbbqAjyd boiJWQrc4rG4tbVEpSFPWWFk/rSnvozrGX2bmG0Eag== X-Google-Smtp-Source: ABdhPJwp3kxwH8yb+NVAAcawjhpi2GUBtHN3D9ybC50c+3BOLdWRk3C4iKCxv4dBtBMWf6wMDV52tSgm6dFPjFOrfKw= X-Received: by 2002:a05:600c:1d01:: with SMTP id l1mr64557876wms.44.1637009785359; Mon, 15 Nov 2021 12:56:25 -0800 (PST) MIME-Version: 1.0 References: <20211110221456.11977-2-jim2101024@gmail.com> <20211111215718.GA1353371@bhelgaas> In-Reply-To: <20211111215718.GA1353371@bhelgaas> From: Jim Quinlan Date: Mon, 15 Nov 2021 15:56:14 -0500 Message-ID: Subject: Re: [PATCH v8 1/8] PCI: brcmstb: Change brcm_phy_stop() to return void To: Bjorn Helgaas Cc: Jim Quinlan , "open list:PCI NATIVE HOST BRIDGE AND ENDPOINT DRIVERS" , Bjorn Helgaas , Nicolas Saenz Julienne , Rob Herring , Mark Brown , "maintainer:BROADCOM BCM7XXX ARM ARCHITECTURE" , Florian Fainelli , Lorenzo Pieralisi , =?UTF-8?Q?Krzysztof_Wilczy=C5=84ski?= , "moderated list:BROADCOM BCM2711/BCM2835 ARM ARCHITECTURE" , "moderated list:BROADCOM BCM2711/BCM2835 ARM ARCHITECTURE" , open list Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 11, 2021 at 4:57 PM Bjorn Helgaas wrote: > > On Wed, Nov 10, 2021 at 05:14:41PM -0500, Jim Quinlan wrote: > > We do not use the result of this function so make it void. > > I don't get it. Can you expand on this? > > brcm_phy_cntl() can return -EIO, which means brcm_phy_stop() can > return -EIO, which means brcm_pcie_suspend can return -EIO. > brcm_pcie_suspend() is the dev_pm_ops.suspend() method. > > So are you saying we never use the result of dev_pm_ops.suspend()? Hi Bjorn, In this situation we are going into suspend. In doing so, any problems with the brcm phy may be erased/forgiven upon resume, since clocks are turned off and most power removed/reduced. An error from brcm_phy_stop() that becomes the return value of brcm_pcie_suspend() will bring a halt to the entire suspend IIRC. In fact, I forced a -EIO in this code and it panic'd on suspend. This is not really the behavior I want for what is most likely a recoverable error. Perhaps a dev_err(...) will suffice while still returning 0? I noticed that reset_control_rearm() also returns a value, and if that is in error it will not be erease/forgiven by suspend sleep. I will fix this. Regards, Jim Quinlan Broadcom STB > > > Signed-off-by: Jim Quinlan > > --- > > drivers/pci/controller/pcie-brcmstb.c | 10 +++++----- > > 1 file changed, 5 insertions(+), 5 deletions(-) > > > > diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c > > index cc30215f5a43..ff7d0d291531 100644 > > --- a/drivers/pci/controller/pcie-brcmstb.c > > +++ b/drivers/pci/controller/pcie-brcmstb.c > > @@ -1111,9 +1111,10 @@ static inline int brcm_phy_start(struct brcm_pcie *pcie) > > return pcie->rescal ? brcm_phy_cntl(pcie, 1) : 0; > > } > > > > -static inline int brcm_phy_stop(struct brcm_pcie *pcie) > > +static inline void brcm_phy_stop(struct brcm_pcie *pcie) > > { > > - return pcie->rescal ? brcm_phy_cntl(pcie, 0) : 0; > > + if (pcie->rescal) > > + brcm_phy_cntl(pcie, 0); > > } > > > > static void brcm_pcie_turn_off(struct brcm_pcie *pcie) > > @@ -1143,14 +1144,13 @@ static void brcm_pcie_turn_off(struct brcm_pcie *pcie) > > static int brcm_pcie_suspend(struct device *dev) > > { > > struct brcm_pcie *pcie = dev_get_drvdata(dev); > > - int ret; > > > > brcm_pcie_turn_off(pcie); > > - ret = brcm_phy_stop(pcie); > > + brcm_phy_stop(pcie); > > reset_control_rearm(pcie->rescal); > > clk_disable_unprepare(pcie->clk); > > > > - return ret; > > + return 0; > > } > > > > static int brcm_pcie_resume(struct device *dev) > > -- > > 2.17.1 > >