From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from phobos.denx.de (phobos.denx.de [85.214.62.61]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B33DB3C470 for ; Fri, 19 Jan 2024 11:15:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=85.214.62.61 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705662954; cv=none; b=GNYyBIb2fOur8J8jOT1CnHUbwFq3en3MpBwKZJG1fGdy4nqkxRw41tkQVtyju2m7CkJRbMaOFg9WyMZjPOPtLsbsrNN8BoawkXhIXoIEhqCEmjRt14apEvFgre/rTf2OTPd937upfawN5HvajD+K25kxQgroa10YlCr16v3u2lU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705662954; c=relaxed/simple; bh=DO+mFZ7HF6rMuHe6kj7D6RUUm/n7CFHefjKby+CVNOo=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=r13g0w59nkwZMcDOFl7noiP905fcyekgnzC6guNTrl8j4ZgtqzHMO6rrbdaWqoTOk1+wHA+3E7QZlydoctTxkseqwXPEI+19eOsjyznuXe8tJZf7Zas2VZ5XNQPXi8Z4javfjnYiZi6ltHTC/KQX1dmZNlMbMwZsM3wozZGvFGo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=denx.de; spf=pass smtp.mailfrom=denx.de; dkim=pass (2048-bit key) header.d=denx.de header.i=@denx.de header.b=bKIwIUGV; arc=none smtp.client-ip=85.214.62.61 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=denx.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=denx.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=denx.de header.i=@denx.de header.b="bKIwIUGV" Received: from [127.0.0.1] (p578adb1c.dip0.t-ipconnect.de [87.138.219.28]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: marex@denx.de) by phobos.denx.de (Postfix) with ESMTPSA id BCFF787A82; Fri, 19 Jan 2024 12:15:49 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=denx.de; s=phobos-20191101; t=1705662950; bh=SUsZc5co9UnGPw9CafszzMNh7dbWHLX8Es5IDCF8Q+M=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=bKIwIUGV1ESVXKbIOMqL5nNhQ7s47t+FdDi6xZp/yJerbxZwm8L2P/J3Jl9HWu9LJ FH/r4ZocLwtrwzZVrVhfFv55x+KO4F0Bf9IHTy7sQojaLOYHLDnRLkpwAL7Lhuz09U ECLF9Cf95+DtBS0WfatGLDJatfPdjN4cXXvYDmjrX6oOTCiLvPgEIQSTDN1WQdoqD1 csc93BhBGnQ+Fucr7mcZgkhj0EkuyJrG39WweP+KGoupfGPgNwZe9L54wZfzqM3oiz SlvM9S47TodIvmRxk+y28e3gTA057A83Dz5NnNKIGmhNUJosB7KlAcD9ISeiPcYolk iMjZN/orw2aCg== Message-ID: <73886bd9-e2ab-40ef-a1a0-a82222d97201@denx.de> Date: Fri, 19 Jan 2024 11:58:54 +0100 Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2] pmdomain: imx8m-blk-ctrl: imx8mp-blk-ctrl: Error out if domains are missing in DT Content-Language: en-US To: =?UTF-8?Q?Uwe_Kleine-K=C3=B6nig?= Cc: linux-pm@vger.kernel.org, Peng Fan , Shawn Guo , Sascha Hauer , Jindong Yue , Marco Felsch , NXP Linux Team , Pengutronix Kernel Team , Ulf Hansson , Fabio Estevam , linux-arm-kernel@lists.infradead.org, Lucas Stach References: <20240119014807.268694-1-marex@denx.de> From: Marek Vasut In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Virus-Scanned: clamav-milter 0.103.8 at phobos.denx.de X-Virus-Status: Clean On 1/19/24 08:42, Uwe Kleine-König wrote: > On Fri, Jan 19, 2024 at 02:47:41AM +0100, Marek Vasut wrote: >> This driver assumes that domain->power_dev is non-NULL in its suspend/resume >> path. The assumption is valid, since all the devices that are being looked up >> here should be described in DT. In case they are not described in DT, beause >> the DT is faulty, suspend/resume attempt would trigger NULL pointer dereference. >> To avoid this failure, check whether the power_dev assignment is not NULL right >> away in probe callback and fail early if it is. >> >> Signed-off-by: Marek Vasut >> --- >> Cc: "Uwe Kleine-König" >> Cc: Fabio Estevam >> Cc: Jindong Yue >> Cc: Lucas Stach >> Cc: Marco Felsch >> Cc: NXP Linux Team >> Cc: Peng Fan >> Cc: Pengutronix Kernel Team >> Cc: Sascha Hauer >> Cc: Shawn Guo >> Cc: Ulf Hansson >> Cc: linux-arm-kernel@lists.infradead.org >> Cc: linux-pm@vger.kernel.org >> --- >> V2: Add extra check for domain being NULL (thanks Peng) >> --- >> drivers/pmdomain/imx/imx8m-blk-ctrl.c | 9 ++++++--- >> drivers/pmdomain/imx/imx8mp-blk-ctrl.c | 9 ++++++--- >> 2 files changed, 12 insertions(+), 6 deletions(-) >> >> diff --git a/drivers/pmdomain/imx/imx8m-blk-ctrl.c b/drivers/pmdomain/imx/imx8m-blk-ctrl.c >> index 1341a707f61bc..ca942d7929c2b 100644 >> --- a/drivers/pmdomain/imx/imx8m-blk-ctrl.c >> +++ b/drivers/pmdomain/imx/imx8m-blk-ctrl.c >> @@ -258,11 +258,14 @@ static int imx8m_blk_ctrl_probe(struct platform_device *pdev) >> >> domain->power_dev = >> dev_pm_domain_attach_by_name(dev, data->gpc_name); >> - if (IS_ERR(domain->power_dev)) { >> - dev_err_probe(dev, PTR_ERR(domain->power_dev), >> + if (IS_ERR_OR_NULL(domain->power_dev)) { >> + if (!domain->power_dev) >> + ret = -ENODEV; >> + else >> + ret = PTR_ERR(domain->power_dev); >> + dev_err_probe(dev, ret, >> "failed to attach power domain \"%s\"\n", >> data->gpc_name); >> - ret = PTR_ERR(domain->power_dev); >> goto cleanup_pds; >> } >> >> diff --git a/drivers/pmdomain/imx/imx8mp-blk-ctrl.c b/drivers/pmdomain/imx/imx8mp-blk-ctrl.c >> index e3203eb6a0229..e488cf79b8007 100644 >> --- a/drivers/pmdomain/imx/imx8mp-blk-ctrl.c >> +++ b/drivers/pmdomain/imx/imx8mp-blk-ctrl.c >> @@ -687,11 +687,14 @@ static int imx8mp_blk_ctrl_probe(struct platform_device *pdev) >> >> domain->power_dev = >> dev_pm_domain_attach_by_name(dev, data->gpc_name); >> - if (IS_ERR(domain->power_dev)) { >> - dev_err_probe(dev, PTR_ERR(domain->power_dev), >> + if (IS_ERR_OR_NULL(domain->power_dev)) { >> + if (!domain->power_dev) >> + ret = -ENODEV; >> + else >> + ret = PTR_ERR(domain->power_dev); >> + dev_err_probe(dev, ret, >> "failed to attach power domain %s\n", >> data->gpc_name); >> - ret = PTR_ERR(domain->power_dev); > > This could be made a bit more compact using: > > domain->power_dev = > dev_pm_domain_attach_by_name(dev, data->gpc_name) || > ERR_PTR(-ENODEV); > if (IS_ERR(domain->power_dev)) { > ret = PTR_ERR(domain->power_dev); > ... > > I'm unsure though if this is human friendly enough?! I think it is only more cryptic and doesn't improve readability. > Having said that I wonder about dev_pm_domain_attach_by_name(). IMHO if > NULL is an error case it and other errors are signaled by error > pointers, there is something to fix there. I don't think dev_pm_domain_attach_by_name() returning NULL is an error -- the domain may be missing from DT and that is legitimate use case I think. But not here, where all the domains should be described in DT because the driver makes assumptions about their presence in the suspend/resume part, and because the DT should fully describe the domains of this hardware anyway, so we better catch such DT issues.