From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 7F37A3B4E81 for ; Wed, 1 Jul 2026 09:20:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782897625; cv=none; b=DWmvaOdIFdccnzZbK0/iUt/M9LbKUp+e2VIiPM6b8uuiRbELm6sMxK38Twya56dekMrYwRX5yhg5MnoEPCPAi0Obj/YcjBM+pqX+FUTS3aBkZsHa9lwygnYxE+9dzlVhItyMfokH/xyZwVVaFX2eNTXw+Lx+SkPpQ03+PZQmWLw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782897625; c=relaxed/simple; bh=iMS7QlGpFIb3nV5N5xKvGc6g2B7VUXc78uu68pn2PyY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=WszBcExPXBFU4rfHE6UsiFI/Vec14BB+Ts3d4Fb+tFMLtPBp/hoNHF6VbhPhX2Ypiym7YKuxcuyaeohf/w0g4KggWAmZRb4fzEzCyBW1Oag2cgOLELuaZuLh9ftpl6YmJTsODuxSza7nTJrVMUfpfZu/6hslgnOL86xLDQPmvVA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=dsOz8qYT; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="dsOz8qYT" 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 6E54B1D15; Wed, 1 Jul 2026 02:20:18 -0700 (PDT) Received: from e129823.arm.com (e129823.arm.com [10.2.213.3]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 58F583F905; Wed, 1 Jul 2026 02:20:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1782897622; bh=iMS7QlGpFIb3nV5N5xKvGc6g2B7VUXc78uu68pn2PyY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=dsOz8qYTQaUth7Od3qXomWYYmuCI0lNYIyXC9Mv7T5zPERdfz95NWbYY5IBsMyKPr 3zKBEt/8zO5baNCddUpSyEIIoUkdXgqtXaHwF7+JRdSXFhoq5xZdsmL3HUjJe53tpU JZSeF/Hm8V/53nE5vGKMUYA+4o6ijW7K3VKRJdhc= Date: Wed, 1 Jul 2026 10:20:17 +0100 From: Yeoreum Yun To: Jie Gan Cc: Suzuki K Poulose , Mike Leach , James Clark , Leo Yan , Alexander Shishkin , Anshuman Khandual , Yuanfang Zhang , Maxime Coquelin , Alexandre Torgue , Tingwei Zhang , coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com Subject: Re: [PATCH 1/2] coresight: Fix clock refcount imbalance on platform remove Message-ID: References: <20260701-fix-clock-refcount-unbalance-v1-0-321dc63c1f90@oss.qualcomm.com> <20260701-fix-clock-refcount-unbalance-v1-1-321dc63c1f90@oss.qualcomm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260701-fix-clock-refcount-unbalance-v1-1-321dc63c1f90@oss.qualcomm.com> Reviewed-by: Yeoreum Yun On Wed, Jul 01, 2026 at 02:05:02PM +0800, Jie Gan wrote: > coresight_get_enable_clocks() enables the programming clock and the > optional AT clock through devm_clk_get_optional_enabled(), which also > registers a devm action to call clk_disable_unprepare() when the driver > detaches. > > After probe, pm_runtime_put() allows the device to suspend and the > runtime suspend callback disables the same clocks. During remove the > device is left runtime suspended, so pm_runtime_disable() freezes it > with the clocks already disabled. The devm cleanup that runs afterwards > calls clk_disable_unprepare() a second time, underflowing the clock > enable refcount. > > Resume the device with pm_runtime_get_sync() before pm_runtime_disable() > so the clocks are enabled again and balance the devm-managed disable. > > This affects all CoreSight platform drivers that obtain their clocks > through coresight_get_enable_clocks(): catu, cpu-debug, ctcu, etm4x, > funnel, replicator, stm, tmc and tpiu. > > Fixes: 1abc1b212eff ("coresight: Appropriately disable programming clocks") > Signed-off-by: Jie Gan > --- > drivers/hwtracing/coresight/coresight-catu.c | 1 + > drivers/hwtracing/coresight/coresight-cpu-debug.c | 1 + > drivers/hwtracing/coresight/coresight-ctcu-core.c | 1 + > drivers/hwtracing/coresight/coresight-etm4x-core.c | 1 + > drivers/hwtracing/coresight/coresight-funnel.c | 1 + > drivers/hwtracing/coresight/coresight-replicator.c | 1 + > drivers/hwtracing/coresight/coresight-stm.c | 1 + > drivers/hwtracing/coresight/coresight-tmc-core.c | 1 + > drivers/hwtracing/coresight/coresight-tpiu.c | 1 + > 9 files changed, 9 insertions(+) > > diff --git a/drivers/hwtracing/coresight/coresight-catu.c b/drivers/hwtracing/coresight/coresight-catu.c > index ad8dafea7d2f..f7e501e6cbd7 100644 > --- a/drivers/hwtracing/coresight/coresight-catu.c > +++ b/drivers/hwtracing/coresight/coresight-catu.c > @@ -647,6 +647,7 @@ static void catu_platform_remove(struct platform_device *pdev) > return; > > __catu_remove(&pdev->dev); > + pm_runtime_get_sync(&pdev->dev); > pm_runtime_disable(&pdev->dev); > } > > diff --git a/drivers/hwtracing/coresight/coresight-cpu-debug.c b/drivers/hwtracing/coresight/coresight-cpu-debug.c > index 3a806c1d50ea..f7efae5b5ce5 100644 > --- a/drivers/hwtracing/coresight/coresight-cpu-debug.c > +++ b/drivers/hwtracing/coresight/coresight-cpu-debug.c > @@ -711,6 +711,7 @@ static void debug_platform_remove(struct platform_device *pdev) > return; > > __debug_remove(&pdev->dev); > + pm_runtime_get_sync(&pdev->dev); > pm_runtime_disable(&pdev->dev); > } > > diff --git a/drivers/hwtracing/coresight/coresight-ctcu-core.c b/drivers/hwtracing/coresight/coresight-ctcu-core.c > index 9043cad42f01..9b6da29d9735 100644 > --- a/drivers/hwtracing/coresight/coresight-ctcu-core.c > +++ b/drivers/hwtracing/coresight/coresight-ctcu-core.c > @@ -266,6 +266,7 @@ static void ctcu_platform_remove(struct platform_device *pdev) > return; > > ctcu_remove(pdev); > + pm_runtime_get_sync(&pdev->dev); > pm_runtime_disable(&pdev->dev); > } > > diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c > index 14bb31bd6a0b..147761024c0f 100644 > --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c > +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c > @@ -2416,6 +2416,7 @@ static void etm4_remove_platform_dev(struct platform_device *pdev) > > if (drvdata) > etm4_remove_dev(drvdata); > + pm_runtime_get_sync(&pdev->dev); > pm_runtime_disable(&pdev->dev); > } > > diff --git a/drivers/hwtracing/coresight/coresight-funnel.c b/drivers/hwtracing/coresight/coresight-funnel.c > index 0abc11f0690c..4c5b94640e6a 100644 > --- a/drivers/hwtracing/coresight/coresight-funnel.c > +++ b/drivers/hwtracing/coresight/coresight-funnel.c > @@ -334,6 +334,7 @@ static void funnel_platform_remove(struct platform_device *pdev) > return; > > funnel_remove(&pdev->dev); > + pm_runtime_get_sync(&pdev->dev); > pm_runtime_disable(&pdev->dev); > } > > diff --git a/drivers/hwtracing/coresight/coresight-replicator.c b/drivers/hwtracing/coresight/coresight-replicator.c > index 2f382de357ee..2d765f1f73b3 100644 > --- a/drivers/hwtracing/coresight/coresight-replicator.c > +++ b/drivers/hwtracing/coresight/coresight-replicator.c > @@ -313,6 +313,7 @@ static void replicator_platform_remove(struct platform_device *pdev) > return; > > replicator_remove(&pdev->dev); > + pm_runtime_get_sync(&pdev->dev); > pm_runtime_disable(&pdev->dev); > } > > diff --git a/drivers/hwtracing/coresight/coresight-stm.c b/drivers/hwtracing/coresight/coresight-stm.c > index 4e860519a73f..a653f1eebeca 100644 > --- a/drivers/hwtracing/coresight/coresight-stm.c > +++ b/drivers/hwtracing/coresight/coresight-stm.c > @@ -1026,6 +1026,7 @@ static void stm_platform_remove(struct platform_device *pdev) > return; > > __stm_remove(&pdev->dev); > + pm_runtime_get_sync(&pdev->dev); > pm_runtime_disable(&pdev->dev); > } > > diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c > index bc5a133ada3e..c9cf486873e2 100644 > --- a/drivers/hwtracing/coresight/coresight-tmc-core.c > +++ b/drivers/hwtracing/coresight/coresight-tmc-core.c > @@ -989,6 +989,7 @@ static void tmc_platform_remove(struct platform_device *pdev) > return; > > __tmc_remove(&pdev->dev); > + pm_runtime_get_sync(&pdev->dev); > pm_runtime_disable(&pdev->dev); > } > > diff --git a/drivers/hwtracing/coresight/coresight-tpiu.c b/drivers/hwtracing/coresight/coresight-tpiu.c > index 7b029d2eb389..72ac93749be1 100644 > --- a/drivers/hwtracing/coresight/coresight-tpiu.c > +++ b/drivers/hwtracing/coresight/coresight-tpiu.c > @@ -286,6 +286,7 @@ static void tpiu_platform_remove(struct platform_device *pdev) > return; > > __tpiu_remove(&pdev->dev); > + pm_runtime_get_sync(&pdev->dev); > pm_runtime_disable(&pdev->dev); > } > > > -- > 2.34.1 > -- Sincerely, Yeoreum Yun