From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751428AbeDDLFG (ORCPT ); Wed, 4 Apr 2018 07:05:06 -0400 Received: from regular1.263xmail.com ([211.150.99.131]:41780 "EHLO regular1.263xmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751053AbeDDLFF (ORCPT ); Wed, 4 Apr 2018 07:05:05 -0400 X-263anti-spam: KSV:0; X-MAIL-GRAY: 0 X-MAIL-DELIVERY: 1 X-KSVirus-check: 0 X-ABS-CHECKED: 4 X-RL-SENDER: jeffy.chen@rock-chips.com X-FST-TO: arnd@arndb.de X-SENDER-IP: 103.29.142.67 X-LOGIN-NAME: jeffy.chen@rock-chips.com X-UNIQUE-TAG: X-ATTACHMENT-NUM: 0 X-DNS-TYPE: 0 Message-ID: <5AC4B151.7060307@rock-chips.com> Date: Wed, 04 Apr 2018 19:04:49 +0800 From: JeffyChen User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:19.0) Gecko/20130126 Thunderbird/19.0 MIME-Version: 1.0 To: Arnd Bergmann , Joerg Roedel , Heiko Stuebner CC: Robin Murphy , Tomasz Figa , Simon Xue , Marc Zyngier , iommu@lists.linux-foundation.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] iommu: rockchip: fix building without CONFIG_OF References: <20180404102401.3634085-1-arnd@arndb.de> In-Reply-To: <20180404102401.3634085-1-arnd@arndb.de> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Amd, Thanks for your patch. On 04/04/2018 06:23 PM, Arnd Bergmann wrote: > We get a build error when compiling the iommu driver without CONFIG_OF: > > drivers/iommu/rockchip-iommu.c: In function 'rk_iommu_of_xlate': > drivers/iommu/rockchip-iommu.c:1101:2: error: implicit declaration of function 'of_dev_put'; did you mean 'of_node_put'? [-Werror=implicit-function-declaration] > oops, didn't notice that. and checking other iommu drivers which call of_find_device_by_node() too, seems they didn't put() it? maybe we should fix them too > This replaces the of_dev_put() with the equivalent platform_device_put(), > and adds an error check for of_find_device_by_node() returning NULL, > which seems to be appropriate here given that we pass the device into > platform_get_drvdata() next, and that of_find_device_by_node() might > theoretically return a NULL pointer. hmm, i thought the of_iommu_xlate() checked that before calling us: static int of_iommu_xlate(struct device *dev, struct of_phandle_args *iommu_spec) { ... if ((ops && !ops->of_xlate) || !of_device_is_available(iommu_spec->np) || (!ops && !of_iommu_driver_present(iommu_spec->np))) return NO_IOMMU; ... return ops->of_xlate(dev, iommu_spec); but it's better to check it ourself :) > > Fixes: 5fd577c3eac3 ("iommu/rockchip: Use OF_IOMMU to attach devices automatically") > Signed-off-by: Arnd Bergmann > --- > This warning appears to only have been introduced in linux-next after > the merge window opened. > --- > drivers/iommu/rockchip-iommu.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/iommu/rockchip-iommu.c b/drivers/iommu/rockchip-iommu.c > index 5fc8656c60f9..fe9c9cc1a9d4 100644 > --- a/drivers/iommu/rockchip-iommu.c > +++ b/drivers/iommu/rockchip-iommu.c > @@ -1094,11 +1094,15 @@ static int rk_iommu_of_xlate(struct device *dev, > return -ENOMEM; > > iommu_dev = of_find_device_by_node(args->np); > + if (!iommu_dev) { > + kfree(data); > + return -ENODEV; > + } > > data->iommu = platform_get_drvdata(iommu_dev); > dev->archdata.iommu = data; > > - of_dev_put(iommu_dev); > + platform_device_put(iommu_dev); > > return 0; > } >