From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 89CEFC4332F for ; Wed, 23 Nov 2022 09:29:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237781AbiKWJ36 (ORCPT ); Wed, 23 Nov 2022 04:29:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46528 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237818AbiKWJ3e (ORCPT ); Wed, 23 Nov 2022 04:29:34 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B0F7145097 for ; Wed, 23 Nov 2022 01:28:03 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id B2538B81EF5 for ; Wed, 23 Nov 2022 09:28:01 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0CBA2C433D7; Wed, 23 Nov 2022 09:27:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1669195680; bh=OyWp4u03SvshycubyCf/r0bvhPPM+gO9J7xu/W3pXGs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xmDxkbYGSzwrsPZ+hU1FeF19R77kZElPM0yvRmP+4iaBw4wLfw3dVrnwc5hKR65kP yCNV26rdwUwjjCBJ+zZvDiBlPQeUfFDvATg42h/NYTSQCUl3W+GJIfzLuL6eua/IIJ Lt1tmQPVuciwot5q5C8+obJ5FpAvXFvd5CWvlGTs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Lukas Wunner , Andre Edich , "David S. Miller" , Sasha Levin Subject: [PATCH 5.10 130/149] usbnet: smsc95xx: Fix deadlock on runtime resume Date: Wed, 23 Nov 2022 09:51:53 +0100 Message-Id: <20221123084602.596048839@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221123084557.945845710@linuxfoundation.org> References: <20221123084557.945845710@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Lukas Wunner [ Upstream commit 7b960c967f2aa01ab8f45c5a0bd78e754cffdeee ] Commit 05b35e7eb9a1 ("smsc95xx: add phylib support") amended smsc95xx_resume() to call phy_init_hw(). That function waits for the device to runtime resume even though it is placed in the runtime resume path, causing a deadlock. The problem is that phy_init_hw() calls down to smsc95xx_mdiobus_read(), which never uses the _nopm variant of usbnet_read_cmd(). Commit b4df480f68ae ("usbnet: smsc95xx: add reset_resume function with reset operation") causes a similar deadlock on resume if the device was already runtime suspended when entering system sleep: That's because the commit introduced smsc95xx_reset_resume(), which calls down to smsc95xx_reset(), which neglects to use _nopm accessors. Fix by auto-detecting whether a device access is performed by the suspend/resume task_struct and use the _nopm variant if so. This works because the PM core guarantees that suspend/resume callbacks are run in task context. Stacktrace for posterity: INFO: task kworker/2:1:49 blocked for more than 122 seconds. Workqueue: usb_hub_wq hub_event schedule rpm_resume __pm_runtime_resume usb_autopm_get_interface usbnet_read_cmd __smsc95xx_read_reg __smsc95xx_phy_wait_not_busy __smsc95xx_mdio_read smsc95xx_mdiobus_read __mdiobus_read mdiobus_read smsc_phy_reset phy_init_hw smsc95xx_resume usb_resume_interface usb_resume_both usb_runtime_resume __rpm_callback rpm_callback rpm_resume __pm_runtime_resume usb_autoresume_device hub_event process_one_work Fixes: b4df480f68ae ("usbnet: smsc95xx: add reset_resume function with reset operation") Signed-off-by: Lukas Wunner Cc: stable@vger.kernel.org # v3.16+ Cc: Andre Edich Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/usb/smsc95xx.c | 27 +++++++++++++++++++++------ 1 file changed, 21 insertions(+), 6 deletions(-) diff --git a/drivers/net/usb/smsc95xx.c b/drivers/net/usb/smsc95xx.c index 65d42f5d42a3..e1cd4c2de2d3 100644 --- a/drivers/net/usb/smsc95xx.c +++ b/drivers/net/usb/smsc95xx.c @@ -61,6 +61,7 @@ struct smsc95xx_priv { u8 suspend_flags; struct mii_bus *mdiobus; struct phy_device *phydev; + struct task_struct *pm_task; }; static bool turbo_mode = true; @@ -70,13 +71,14 @@ MODULE_PARM_DESC(turbo_mode, "Enable multiple frames per Rx transaction"); static int __must_check __smsc95xx_read_reg(struct usbnet *dev, u32 index, u32 *data, int in_pm) { + struct smsc95xx_priv *pdata = dev->driver_priv; u32 buf; int ret; int (*fn)(struct usbnet *, u8, u8, u16, u16, void *, u16); BUG_ON(!dev); - if (!in_pm) + if (current != pdata->pm_task) fn = usbnet_read_cmd; else fn = usbnet_read_cmd_nopm; @@ -100,13 +102,14 @@ static int __must_check __smsc95xx_read_reg(struct usbnet *dev, u32 index, static int __must_check __smsc95xx_write_reg(struct usbnet *dev, u32 index, u32 data, int in_pm) { + struct smsc95xx_priv *pdata = dev->driver_priv; u32 buf; int ret; int (*fn)(struct usbnet *, u8, u8, u16, u16, const void *, u16); BUG_ON(!dev); - if (!in_pm) + if (current != pdata->pm_task) fn = usbnet_write_cmd; else fn = usbnet_write_cmd_nopm; @@ -1468,9 +1471,12 @@ static int smsc95xx_suspend(struct usb_interface *intf, pm_message_t message) u32 val, link_up; int ret; + pdata->pm_task = current; + ret = usbnet_suspend(intf, message); if (ret < 0) { netdev_warn(dev->net, "usbnet_suspend error\n"); + pdata->pm_task = NULL; return ret; } @@ -1717,6 +1723,7 @@ static int smsc95xx_suspend(struct usb_interface *intf, pm_message_t message) if (ret && PMSG_IS_AUTO(message)) usbnet_resume(intf); + pdata->pm_task = NULL; return ret; } @@ -1737,29 +1744,31 @@ static int smsc95xx_resume(struct usb_interface *intf) /* do this first to ensure it's cleared even in error case */ pdata->suspend_flags = 0; + pdata->pm_task = current; + if (suspend_flags & SUSPEND_ALLMODES) { /* clear wake-up sources */ ret = smsc95xx_read_reg_nopm(dev, WUCSR, &val); if (ret < 0) - return ret; + goto done; val &= ~(WUCSR_WAKE_EN_ | WUCSR_MPEN_); ret = smsc95xx_write_reg_nopm(dev, WUCSR, val); if (ret < 0) - return ret; + goto done; /* clear wake-up status */ ret = smsc95xx_read_reg_nopm(dev, PM_CTRL, &val); if (ret < 0) - return ret; + goto done; val &= ~PM_CTL_WOL_EN_; val |= PM_CTL_WUPS_; ret = smsc95xx_write_reg_nopm(dev, PM_CTRL, val); if (ret < 0) - return ret; + goto done; } ret = usbnet_resume(intf); @@ -1767,15 +1776,21 @@ static int smsc95xx_resume(struct usb_interface *intf) netdev_warn(dev->net, "usbnet_resume error\n"); phy_init_hw(pdata->phydev); + +done: + pdata->pm_task = NULL; return ret; } static int smsc95xx_reset_resume(struct usb_interface *intf) { struct usbnet *dev = usb_get_intfdata(intf); + struct smsc95xx_priv *pdata = dev->driver_priv; int ret; + pdata->pm_task = current; ret = smsc95xx_reset(dev); + pdata->pm_task = NULL; if (ret < 0) return ret; -- 2.35.1