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| author |   Ken Xue <ken.xue@amd.com> | 2015-12-01 14:45:23 +0800 |
|---|---|---|
| committer |   Martin K. Petersen <martin.petersen@oracle.com> | 2015-12-10 12:24:44 -0500 |
| commit | 1c69d3b6eb73e466ecbb8edaf1bc7fd585b288da (patch) | |
| tree | 5b0a2eb7bd68f8c902b75d6b0fc7b252e532f92c /drivers/scsi/scsi_pm.c | |
| parent | Linux 4.4-rc4 (diff) | |
| download | linux-dev-1c69d3b6eb73e466ecbb8edaf1bc7fd585b288da.tar.xz linux-dev-1c69d3b6eb73e466ecbb8edaf1bc7fd585b288da.zip | |
Revert "SCSI: Fix NULL pointer dereference in runtime PM"
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 <Ken.Xue@amd.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: Xiangliang Yu <Xiangliang.Yu@amd.com>
Cc: James E.J. Bottomley <JBottomley@odin.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Michael Terry <Michael.terry@canonical.com>
Cc: stable@vger.kernel.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/scsi/scsi_pm.c')
| -rw-r--r-- | drivers/scsi/scsi_pm.c | 20 |
1 files changed, 10 insertions, 10 deletions
diff --git a/drivers/scsi/scsi_pm.c b/drivers/scsi/scsi_pm.c index e4b799837948..459abe1dcc87 100644 --- a/drivers/scsi/scsi_pm.c +++ b/drivers/scsi/scsi_pm.c @@ -219,13 +219,13 @@ 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; } @@ -248,11 +248,11 @@ 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; } |