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authorKen Xue <ken.xue@amd.com>2015-12-01 14:45:23 +0800
committerMartin K. Petersen <martin.petersen@oracle.com>2015-12-10 12:24:44 -0500
commit1c69d3b6eb73e466ecbb8edaf1bc7fd585b288da (patch)
tree5b0a2eb7bd68f8c902b75d6b0fc7b252e532f92c
parent527e9316f8ec44bd53d90fb9f611fa7ffff52bb9 (diff)
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>
-rw-r--r--drivers/scsi/scsi_pm.c20
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;
}