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spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=z9GnV3ZBqv/X4MXTX820Gv6lK6kQB5rOWM7Qztyz8O8=; b=o4n6mg+eZwCCUL mJ+2zSUTkmw+5eapK2vo6S5HL9lU3msrO0C1KQ/sVwUCZgTnblEKgIQ3EmbT/75aUO1nK9dL7X3Ni RQeiAqngJCXsdZiDSxIXC1dDYyBJg3PvHSV0FW0WLU92iJmXRscCgMUSyNM2vD/UnrNK3YIvH9Sxi B8KRKavft9SZwAM8/90PxH40q/BahiFGjdp+SWpQr1XKVelF57RIqECwEN+tGyCDDXHLHlQFiWXzB GqFKaGgPWqddE5zu30AQdnu1EO5NVM4bSNcevlj43VFm6FDAeFKMkbskCwYNxFvk13diwNQifCmUF bY+cHVdplevweLR6jaeg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1lolDw-008FFK-Km; Thu, 03 Jun 2021 11:09:16 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1lolDs-008FDi-Hg for linux-arm-kernel@lists.infradead.org; Thu, 03 Jun 2021 11:09:13 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id 6B771613DC; Thu, 3 Jun 2021 11:09:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1622718552; bh=oulCTMRij/0YKDHZtxJlmXnKJmrq738g2Nu5+8hJZhk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=uEQn0pJD1PpIW/izJTVru84b4xULfY30cOgBeXGpgSr7q5q89Jf33lpwgdwsqXLlT biDKRwbm7WED7jPvms1Cyc5RgvtroAhrGbmW7f8W7pHWmgm97ATjGqDbGyWeG4UImp l2zOPwL9yFJYCiUrmaSCutPVRLYtpU2MetnIHIJ/4bEmM2qvbCf3l3kI1xvDTnLi8P jPQh+3lQ6ap43tRTp5K+DPtNPGiPa2l6axks1L42ELpdYspCMnQZqVtgz8sDgbFXFY j9cnekwJbpza7J93CZaPTIwHmIq/IEtOltSu61nImCQcYJKQKwvo8WrZhGCYEIm2FA tdGFp450SBXdg== Date: Thu, 3 Jun 2021 16:39:08 +0530 From: Vinod Koul To: Johan Hovold Cc: "yukuai (C)" , mcoquelin.stm32@gmail.com, alexandre.torgue@foss.st.com, michal.simek@xilinx.com, dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, yi.zhang@huawei.com Subject: Re: [PATCH 2/3] dmaengine: usb-dmac: Fix PM reference leak in usb_dmac_probe() Message-ID: References: <20210517081826.1564698-1-yukuai3@huawei.com> <20210517081826.1564698-3-yukuai3@huawei.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210603_040912_642086_5C99012D X-CRM114-Status: GOOD ( 29.52 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 31-05-21, 11:19, Johan Hovold wrote: > On Mon, May 31, 2021 at 02:27:34PM +0530, Vinod Koul wrote: > > On 31-05-21, 14:11, yukuai (C) wrote: > > > On 2021/05/31 12:00, Vinod Koul wrote: > > > > On 17-05-21, 16:18, Yu Kuai wrote: > > > > > pm_runtime_get_sync will increment pm usage counter even it failed. > > > > > Forgetting to putting operation will result in reference leak here. > > > > > Fix it by replacing it with pm_runtime_resume_and_get to keep usage > > > > > counter balanced. > > > > > > > > > > Reported-by: Hulk Robot > > > > > Signed-off-by: Yu Kuai > > > > > --- > > > > > drivers/dma/sh/usb-dmac.c | 2 +- > > > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > > > > > diff --git a/drivers/dma/sh/usb-dmac.c b/drivers/dma/sh/usb-dmac.c > > > > > index 8f7ceb698226..2a6c8fd8854e 100644 > > > > > --- a/drivers/dma/sh/usb-dmac.c > > > > > +++ b/drivers/dma/sh/usb-dmac.c > > > > > @@ -796,7 +796,7 @@ static int usb_dmac_probe(struct platform_device *pdev) > > > > > /* Enable runtime PM and initialize the device. */ > > > > > pm_runtime_enable(&pdev->dev); > > > > > - ret = pm_runtime_get_sync(&pdev->dev); > > > > > + ret = pm_runtime_resume_and_get(&pdev->dev); > > > > > > > > This does not seem to fix anything.. the below goto goes and disables > > > > the runtime_pm for this device and thus there wont be any leak > > > Hi, > > > > > > If pm_runtime_get_sync() fails and increments the pm.usage_count > > > variable, pm_runtime_disable() does not reset the counter, and > > > we still need to decrement the usage count when pm_runtime_get_sync() > > > fails. Do I miss anthing? > > > > Yes the rumtime_pm is disabled on failure here and the count would have > > no consequence... > > You should still balance the PM usage counter as it isn't reset for > example when reloading the driver. Should I driver trust that on load PM usage counter is balanced and not to be reset..? > Using pm_runtime_resume_and_get() is one way of handling this, but > alternatively you could also move the error_pm label above the > pm_runtime_put() in the error path. That would be a better way I think -- ~Vinod _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel