From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D780D50EC13; Wed, 16 Sep 2026 17:39:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789580347; cv=none; b=usGE3t3eBdfb3b6BCh9i2xistCQolD4zv3g9IHlDzh9LDq7udDLA2WZUpqqfLt9b9h7ghNb7qqkRqGCl3PMiqGVyYTU4VfN2AlWJr5YUPZxPSP1RrOS7Lo4fLwqV8IfIi5EknSWs6dLRqkbFA8aXTWu1tmo04V39Zc0lv9vmZbw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789580347; c=relaxed/simple; bh=1n2xg/JoPY4kIbe3mE4yyuTv5TFw3hrpgNEEZQHM9qw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Q9qpZtx11/2JAegA7tby/KdCpJ7Sjp6CgDgyifvDog0zpYXLBCVngbUvdzEQv6ZuVKoQzSWq7X9JfpsBSkcojazZoqSJ1VJnovBsVReeyM6rwPB9VEH7sz1UmBEKhfR6Nf90liHza7xQaknC9K076E3/oBk3nbYjc9NPQ35dQ8U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=JKjnQsRx; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="JKjnQsRx" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 431EE1F0089A; Wed, 16 Sep 2026 17:39:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789580341; bh=Hw/R8i8meAA1zGDzRH9AGbiNJd1vryQPS42R/yDvgrw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=JKjnQsRxjXBgEg6lmIflMrd91xGrzhV/zR0ZR5jpj+6ZyBStCMoH2fqEYxe/wTOp/ uuVFcEEFaglpcjwXx+GC7nnEhX26Ss2pIXlEsvnNSQFS8l6Pkb1SWxsg1fFup702xH qTvROjAkedcIHSOdcfIbvx9SPLZry36E0S/Squ0SRlKLJe6CYf5COUDCOzAzEo82A3 8bUtzxO9UaQrhs9PEnKWVE0Fuujc/v+T3pR4YzwGk6wza+NrmSFFCYrxw+QxFEX/uK jTZzDMzKaGYl2xyTFeOvmyidvxFI1A1EOVCe0XxmCzrX0qyhNj34Ah4Dw+7DVWw88F WZ17BtYeYwyRg== From: William Breathitt Gray To: Wentao Liang Cc: William Breathitt Gray , biju.das.jz@bp.renesas.com, lee@kernel.org, linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, linux-renesas-soc@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH] counter: rz-mtu3-cnt: Fix runtime PM leak in rz_mtu3_count_enable_write() Date: Wed, 16 Sep 2026 13:38:43 -0400 Message-ID: <20260916173845.1820981-1-wbg@kernel.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260916092242.2001358-1-vulab@iscas.ac.cn> References: <20260916092242.2001358-1-vulab@iscas.ac.cn> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2265; i=wbg@kernel.org; h=from:subject; bh=1n2xg/JoPY4kIbe3mE4yyuTv5TFw3hrpgNEEZQHM9qw=; b=owGbwMvMwCW21SPs1D4hZW3G02pJDFmrLj/e/GzDrU2HJ6yt1taZ33FOwu5Wtwej4jn+WP29r +bvqFNl6ShlYRDjYpAVU2TpNT9798ElVY0fL+Zvg5nDygQyhIGLUwAm0veTkWF5e01K96lXYbs4 9on/vXDD/N2j/UIvrE8F8zzwfOS2774swz/1A3fUWTUmMMm3rWRrSn+XLDJpwV/Bw/I75Rta40r 3inMBAA== X-Developer-Key: i=wbg@kernel.org; a=openpgp; fpr=8D37CDDDE0D22528F8E89FB6B54856CABE12232B Content-Transfer-Encoding: 8bit On Wed, Sep 16, 2026 at 09:22:42AM +0000, Wentao Liang wrote: > When enabling a counter, the runtime PM reference taken by > pm_runtime_get_sync() is never dropped if rz_mtu3_initialize_counter() > fails and returns an error, e.g. -EBUSY when the channel is already > requested. Because priv->count_is_enabled[] is left false, a subsequent > disable write also takes the early exit path, so the reference is never > recovered. Additionally, if pm_runtime_get_sync() itself fails the > device usage count is left incremented while the hardware is still > accessed with runtime PM suspended. > > Use pm_runtime_resume_and_get() to resume the device and bail out if it > fails, and drop the runtime PM reference when > rz_mtu3_initialize_counter() fails. > > Fixes: 0be8907359df ("counter: Add Renesas RZ/G2L MTU3a counter driver") > Cc: stable@vger.kernel.org > Signed-off-by: Wentao Liang > --- > drivers/counter/rz-mtu3-cnt.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/drivers/counter/rz-mtu3-cnt.c b/drivers/counter/rz-mtu3-cnt.c > index 7bfb6979193c..2bfc92bea757 100644 > --- a/drivers/counter/rz-mtu3-cnt.c > +++ b/drivers/counter/rz-mtu3-cnt.c > @@ -504,10 +504,15 @@ static int rz_mtu3_count_enable_write(struct counter_device *counter, > goto exit; > > if (enable) { > - pm_runtime_get_sync(counter->parent); > + ret = pm_runtime_resume_and_get(counter->parent); > + if (ret) > + goto exit; > + > ret = rz_mtu3_initialize_counter(counter, count->id); > if (ret == 0) > priv->count_is_enabled[count->id] = true; > + else > + pm_runtime_put(counter->parent); > } else { > rz_mtu3_terminate_counter(counter, count->id); > priv->count_is_enabled[count->id] = false; > -- > 2.34.1 > Hello Wentao, This looks like an earlier patch submission we've received.[^1] In fact, I wonder whether these patches will be necessary anymore if the "counter: rz-mtu3-cnt: check clock and runtime PM errors" series is merged.[^2] Sincerely, William Breathitt Gray [^1]: https://lore.kernel.org/all/20260814134138.1388045-1-ruoyuw560@gmail.com/ [^2]: https://lore.kernel.org/all/20260903090719.3498955-1-dayou5941@163.com/