From patchwork Tue Nov 10 09:29:33 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhang Qilong X-Patchwork-Id: 11893677 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 473C61668 for ; Tue, 10 Nov 2020 09:25:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3385220781 for ; Tue, 10 Nov 2020 09:25:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730623AbgKJJZx (ORCPT ); Tue, 10 Nov 2020 04:25:53 -0500 Received: from szxga05-in.huawei.com ([45.249.212.191]:7622 "EHLO szxga05-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730512AbgKJJZv (ORCPT ); Tue, 10 Nov 2020 04:25:51 -0500 Received: from DGGEMS401-HUB.china.huawei.com (unknown [172.30.72.59]) by szxga05-in.huawei.com (SkyGuard) with ESMTP id 4CVjC60ZlnzLtjZ; Tue, 10 Nov 2020 17:25:38 +0800 (CST) Received: from huawei.com (10.175.127.227) by DGGEMS401-HUB.china.huawei.com (10.3.19.201) with Microsoft SMTP Server id 14.3.487.0; Tue, 10 Nov 2020 17:25:46 +0800 From: Zhang Qilong To: , , , CC: , Subject: [PATCH v3 2/2] net: fec: Fix reference count leak in fec series ops Date: Tue, 10 Nov 2020 17:29:33 +0800 Message-ID: <20201110092933.3342784-3-zhangqilong3@huawei.com> X-Mailer: git-send-email 2.25.4 In-Reply-To: <20201110092933.3342784-1-zhangqilong3@huawei.com> References: <20201110092933.3342784-1-zhangqilong3@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.127.227] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org pm_runtime_get_sync() will increment pm usage at first and it will resume the device later. If runtime of the device has error or device is in inaccessible state(or other error state), resume operation will fail. If we do not call put operation to decrease the reference, it will result in reference count leak. Moreover, this device cannot enter the idle state and always stay busy or other non-idle state later. So we fixed it by replacing it with pm_runtime_resume_and_get. Fixes: 8fff755e9f8d0 ("net: fec: Ensure clocks are enabled while using mdio bus") Signed-off-by: Zhang Qilong --- drivers/net/ethernet/freescale/fec_main.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c index d7919555250d..04f24c66cf36 100644 --- a/drivers/net/ethernet/freescale/fec_main.c +++ b/drivers/net/ethernet/freescale/fec_main.c @@ -1808,7 +1808,7 @@ static int fec_enet_mdio_read(struct mii_bus *bus, int mii_id, int regnum) int ret = 0, frame_start, frame_addr, frame_op; bool is_c45 = !!(regnum & MII_ADDR_C45); - ret = pm_runtime_get_sync(dev); + ret = pm_runtime_resume_and_get(dev); if (ret < 0) return ret; @@ -1867,11 +1867,9 @@ static int fec_enet_mdio_write(struct mii_bus *bus, int mii_id, int regnum, int ret, frame_start, frame_addr; bool is_c45 = !!(regnum & MII_ADDR_C45); - ret = pm_runtime_get_sync(dev); + ret = pm_runtime_resume_and_get(dev); if (ret < 0) return ret; - else - ret = 0; if (is_c45) { frame_start = FEC_MMFR_ST_C45; @@ -2275,7 +2273,7 @@ static void fec_enet_get_regs(struct net_device *ndev, u32 i, off; int ret; - ret = pm_runtime_get_sync(dev); + ret = pm_runtime_resume_and_get(dev); if (ret < 0) return; @@ -2976,7 +2974,7 @@ fec_enet_open(struct net_device *ndev) int ret; bool reset_again; - ret = pm_runtime_get_sync(&fep->pdev->dev); + ret = pm_runtime_resume_and_get(&fep->pdev->dev); if (ret < 0) return ret; @@ -3770,7 +3768,7 @@ fec_drv_remove(struct platform_device *pdev) struct device_node *np = pdev->dev.of_node; int ret; - ret = pm_runtime_get_sync(&pdev->dev); + ret = pm_runtime_resume_and_get(&pdev->dev); if (ret < 0) return ret;