From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755571AbcAXWEK (ORCPT ); Sun, 24 Jan 2016 17:04:10 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:60763 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755373AbcAXWDj (ORCPT ); Sun, 24 Jan 2016 17:03:39 -0500 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Ken Xue , Xiangliang Yu , "James E . J . Bottomley" , Jens Axboe , Michael Terry , "Martin K . Petersen" , Luis Henriques Subject: [PATCH 3.16.y-ckt 059/128] Revert "SCSI: Fix NULL pointer dereference in runtime PM" Date: Sun, 24 Jan 2016 22:00:14 +0000 Message-Id: <1453672883-2708-60-git-send-email-luis.henriques@canonical.com> In-Reply-To: <1453672883-2708-1-git-send-email-luis.henriques@canonical.com> References: <1453672883-2708-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.7-ckt23 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: Ken Xue commit 1c69d3b6eb73e466ecbb8edaf1bc7fd585b288da upstream. This reverts commit 49718f0fb8c9 ("SCSI: Fix NULL pointer dereference in runtime PM") The old commit may lead to a issue that blk_{pre|post}_runtime_suspend and blk_{pre|post}_runtime_resume may not be called in pairs. Take sr device as example, when sr device goes to runtime suspend, blk_{pre|post}_runtime_suspend will be called since sr device defined pm->runtime_suspend. But blk_{pre|post}_runtime_resume will not be called since sr device doesn't have pm->runtime_resume. so, sr device can not resume correctly anymore. More discussion can be found from below link. http://marc.info/?l=linux-scsi&m=144163730531875&w=2 Signed-off-by: Ken Xue Acked-by: Alan Stern Cc: Xiangliang Yu Cc: James E.J. Bottomley Cc: Jens Axboe Cc: Michael Terry Signed-off-by: Martin K. Petersen Signed-off-by: Luis Henriques --- drivers/scsi/scsi_pm.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) diff --git a/drivers/scsi/scsi_pm.c b/drivers/scsi/scsi_pm.c index a2dcf6a54ec6..75320dad9677 100644 --- a/drivers/scsi/scsi_pm.c +++ b/drivers/scsi/scsi_pm.c @@ -221,13 +221,13 @@ static int sdev_runtime_suspend(struct device *dev) struct scsi_device *sdev = to_scsi_device(dev); int err = 0; - if (pm && pm->runtime_suspend) { - err = blk_pre_runtime_suspend(sdev->request_queue); - if (err) - return err; + err = blk_pre_runtime_suspend(sdev->request_queue); + if (err) + return err; + if (pm && pm->runtime_suspend) err = pm->runtime_suspend(dev); - blk_post_runtime_suspend(sdev->request_queue, err); - } + blk_post_runtime_suspend(sdev->request_queue, err); + return err; } @@ -250,11 +250,11 @@ static int sdev_runtime_resume(struct device *dev) const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; int err = 0; - if (pm && pm->runtime_resume) { - blk_pre_runtime_resume(sdev->request_queue); + blk_pre_runtime_resume(sdev->request_queue); + if (pm && pm->runtime_resume) err = pm->runtime_resume(dev); - blk_post_runtime_resume(sdev->request_queue, err); - } + blk_post_runtime_resume(sdev->request_queue, err); + return err; }