From nobody Fri Dec 19 20:34:19 2025 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 72737627E8; Wed, 13 Mar 2024 16:42:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710348150; cv=none; b=FrkATvDBd3Ppxg5ZJXcbBK+04O1MCXIF2RJOl+YEDCoKybAnUPCpPcmGUfpy0aJz/c9sXEh+Tbl7NVrTI2HWdn+3FgfrL1zvBG1R28t7WbzB5q7pi2L8EsqZBIYMe1WEcdXV/JWs/45UH+jFk+dhZAPgxeRx9C69Ze5zkNX+qeg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710348150; c=relaxed/simple; bh=ZnVYI0EVRMPAR8YuEzTHJ8BKEfsGMglMjd5MZe0BcTY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=sKlfmIqyZBzvPp/tLoh0OX85Jg9F67GTRWUlZZJgv5v7z4o05cfb7GKl/vDoK+ksWrVbbqWOW1Kfu4jsefQOcq3Mjq3LlnNnNDlelIiiA9uqVYsfFN2gdF+vxuVfASuhAVprUmB52a+9xvuVGD9HfrnR4xiVki4f8mF/gj42n44= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=QdVz807g; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="QdVz807g" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2D227C433B1; Wed, 13 Mar 2024 16:42:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1710348150; bh=ZnVYI0EVRMPAR8YuEzTHJ8BKEfsGMglMjd5MZe0BcTY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QdVz807gDjqumUkrg7+XL1zFfu2v43PCeqQlpbXVHDB/tTzHmGVVqckBY8keOhV0E Jlq7DM/aFgGwnWx0mlDRzHrkBSqbctC2qEL6OXKnaDd59HiH9MBMOSaCS1tFYZofjH 22hcdLvbOM6l33Dld5UJg3o5i1vwop7sKTiv0TBwXPqj1aikFueR+d9j52PGMdmn1S 1Jkh5B3UbfF2BTzNM0fAPpeUK6uqnzvKQGoGuvMEh7ZzUF8k1EyfBkerPEufy3qMjp ZonZnLHDrTw1e5yXbA7rF/v3OnF6eBOCc9erJKmkzW97erEyj6CDbA1RWBEdEUiqZM RWf/cZa4vcFsA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Oleksij Rempel , Jiri Pirko , "David S . Miller" , Sasha Levin Subject: [PATCH 5.15 03/76] net: lan78xx: fix runtime PM count underflow on link stop Date: Wed, 13 Mar 2024 12:41:10 -0400 Message-ID: <20240313164223.615640-4-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240313164223.615640-1-sashal@kernel.org> References: <20240313164223.615640-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-KernelTest-Patch: http://kernel.org/pub/linux/kernel/v5.x/stable-review/patch-5.15.152-rc1.gz X-KernelTest-Tree: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git X-KernelTest-Branch: linux-5.15.y X-KernelTest-Patches: git://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git X-KernelTest-Version: 5.15.152-rc1 X-KernelTest-Deadline: 2024-03-15T16:42+00:00 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Oleksij Rempel [ Upstream commit 1eecc7ab82c42133b748e1895275942a054a7f67 ] Current driver has some asymmetry in the runtime PM calls. On lan78xx_open() it will call usb_autopm_get() and unconditionally usb_autopm_put(). And on lan78xx_stop() it will call only usb_autopm_put(). So far, it was working only because this driver do not activate autosuspend by default, so it was visible only by warning "Runtime PM usage count underflow!". Since, with current driver, we can't use runtime PM with active link, execute lan78xx_open()->usb_autopm_put() only in error case. Otherwise, keep ref counting high as long as interface is open. Fixes: 55d7de9de6c3 ("Microchip's LAN7800 family USB 2/3 to 10/100/1000 Eth= ernet device driver") Signed-off-by: Oleksij Rempel Reviewed-by: Jiri Pirko Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/usb/lan78xx.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c index c8b42892655a1..77cb30259dca7 100644 --- a/drivers/net/usb/lan78xx.c +++ b/drivers/net/usb/lan78xx.c @@ -2960,7 +2960,8 @@ static int lan78xx_open(struct net_device *net) done: mutex_unlock(&dev->dev_mutex); =20 - usb_autopm_put_interface(dev->intf); + if (ret < 0) + usb_autopm_put_interface(dev->intf); =20 return ret; } --=20 2.43.0