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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 27455CD98CE for ; Thu, 11 Jun 2026 15:58:09 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 7012010EFF9; Thu, 11 Jun 2026 15:58:08 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=arm.com header.i=@arm.com header.b="tkqgXSVO"; dkim-atps=neutral Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by gabe.freedesktop.org (Postfix) with ESMTP id 8AA9210EFF7 for ; Thu, 11 Jun 2026 15:58:07 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 378EE1516 for ; Thu, 11 Jun 2026 08:58:02 -0700 (PDT) Received: from [192.168.0.1] (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id B95B73FB90 for ; Thu, 11 Jun 2026 08:58:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1781193487; bh=JjgcsqnCxL3j20VMBBvzPgr+g2M5UACBDHsxu7RFV3Q=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=tkqgXSVOhiM6WdiJ0RwLoncitvStwoo1QJpKh5MiQyk3VVXS+OEvPLku+EYUn+PUw pHJouBqcdbQd3V/u0wTIvANEXBTpp5Cfvi0ClvbwvjYcfkvf6hcPr3hxKU2/yz9+nD KtoOmnmoPG8kpDAs2uB86xzr1mQfh+DnJcO5d44o= Date: Thu, 11 Jun 2026 16:58:04 +0100 From: Liviu Dudau To: Gustavo Kenji =?utf-8?B?TWVuZG9uw6dh?= Kaneko Cc: dri-devel@lists.freedesktop.org, maarten.lankhorst@linux.intel.com, mripard@kernel.org, tzimmermann@suse.de, airlied@gmail.com, simona@ffwll.ch, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] drm/arm/komeda: fix error handling for clk_prepare_enable() and callers Message-ID: References: <20260609130828.1066038-1-kaneko.dev@pm.me> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20260609130828.1066038-1-kaneko.dev@pm.me> X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Tue, Jun 09, 2026 at 01:08:33PM +0000, Gustavo Kenji Mendonça Kaneko wrote: > komeda_dev_resume() calls clk_prepare_enable() without checking the > return value. If the clock fails to enable, the function returns 0 > (success) while IRQs are enabled and IOMMU is connected on potentially > unclocked hardware, causing undefined behavior on resume. > > Propagate the error from clk_prepare_enable() and fix all call sites > in komeda_drv.c that previously ignored the return value of > komeda_dev_resume(): > > - komeda_platform_probe(): if resume fails, jump to err_destroy_mdev > (skipping the suspend call, since the clock was never enabled) > - komeda_pm_resume(): propagate the error and skip > drm_mode_config_helper_resume() on failure > > This issue was found by code review without access to Komeda hardware. > > Signed-off-by: Gustavo Kenji Mendonça Kaneko Reviewed-by: Liviu Dudau Best regards, Liviu > --- > Changes in v2: > - Fix all call sites in komeda_drv.c that ignored the return value of > komeda_dev_resume() (Liviu Dudau) > - In komeda_platform_probe(), use a new err_destroy_mdev label to skip > the komeda_dev_suspend() call when resume itself failed > - In komeda_pm_resume(), propagate the error from komeda_dev_resume() > and skip drm_mode_config_helper_resume() on failure > > drivers/gpu/drm/arm/display/komeda/komeda_dev.c | 6 +++++- > drivers/gpu/drm/arm/display/komeda/komeda_drv.c | 14 +++++++++----- > 2 files changed, 14 insertions(+), 6 deletions(-) > > diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_dev.c b/drivers/gpu/drm/arm/display/komeda/komeda_dev.c > index 5ba62e637a61..9aad1d1d28ec 100644 > --- a/drivers/gpu/drm/arm/display/komeda/komeda_dev.c > +++ b/drivers/gpu/drm/arm/display/komeda/komeda_dev.c > @@ -313,7 +313,11 @@ void komeda_dev_destroy(struct komeda_dev *mdev) > > int komeda_dev_resume(struct komeda_dev *mdev) > { > - clk_prepare_enable(mdev->aclk); > + int err; > + > + err = clk_prepare_enable(mdev->aclk); > + if (err) > + return err; > > mdev->funcs->enable_irq(mdev); > > diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_drv.c b/drivers/gpu/drm/arm/display/komeda/komeda_drv.c > index 4bb5f250e95e..67fffab018ae 100644 > --- a/drivers/gpu/drm/arm/display/komeda/komeda_drv.c > +++ b/drivers/gpu/drm/arm/display/komeda/komeda_drv.c > @@ -74,8 +74,11 @@ static int komeda_platform_probe(struct platform_device *pdev) > } > > pm_runtime_enable(dev); > - if (!pm_runtime_enabled(dev)) > - komeda_dev_resume(mdrv->mdev); > + if (!pm_runtime_enabled(dev)) { > + err = komeda_dev_resume(mdrv->mdev); > + if (err) > + goto err_destroy_mdev; > + } > > mdrv->kms = komeda_kms_attach(mdrv->mdev); > if (IS_ERR(mdrv->kms)) { > @@ -93,7 +96,7 @@ static int komeda_platform_probe(struct platform_device *pdev) > pm_runtime_disable(dev); > else > komeda_dev_suspend(mdrv->mdev); > - > +err_destroy_mdev: > komeda_dev_destroy(mdrv->mdev); > > free_mdrv: > @@ -140,11 +143,12 @@ static int __maybe_unused komeda_pm_suspend(struct device *dev) > static int __maybe_unused komeda_pm_resume(struct device *dev) > { > struct komeda_drv *mdrv = dev_get_drvdata(dev); > + int err = 0; > > if (!pm_runtime_status_suspended(dev)) > - komeda_dev_resume(mdrv->mdev); > + err = komeda_dev_resume(mdrv->mdev); > > - return drm_mode_config_helper_resume(&mdrv->kms->base); > + return err ? err : drm_mode_config_helper_resume(&mdrv->kms->base); > } > > static const struct dev_pm_ops komeda_pm_ops = { > -- > 2.54.0 > > -- ==================== | I would like to | | fix the world, | | but they're not | | giving me the | \ source code! / --------------- ¯\_(ツ)_/¯