| Message ID | 1607917296-11735-1-git-send-email-cang@codeaurora.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [V2,1/1] scsi: ufs: Fix a possible NULL pointer issue | expand |
On Sun, 2020-12-13 at 19:41 -0800, Can Guo wrote: > Fixes: 88a92d6ae4fe ("scsi: ufs: Serialize eh_work with system PM > events and async scan") > > Signed-off-by: Can Guo <cang@codeaurora.org> > --- > drivers/scsi/ufs/ufshcd.c | 9 +++++---- > 1 file changed, 5 insertions(+), 4 deletions(-) > > diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c > index c1c401b..ef155a9 100644 > --- a/drivers/scsi/ufs/ufshcd.c > +++ b/drivers/scsi/ufs/ufshcd.c > @@ -8883,8 +8883,11 @@ int ufshcd_system_suspend(struct ufs_hba *hba) > int ret = 0; > ktime_t start = ktime_get(); > > + if (!hba) > + return 0; > + > down(&hba->eh_sem); > - if (!hba || !hba->is_powered) > + if (!hba->is_powered) > return 0; Can, why not moving down(&hba->eh_sem) after "return 0;"?
On 2020-12-14 22:32, Bean Huo wrote: > On Sun, 2020-12-13 at 19:41 -0800, Can Guo wrote: >> Fixes: 88a92d6ae4fe ("scsi: ufs: Serialize eh_work with system PM >> events and async scan") >> >> Signed-off-by: Can Guo <cang@codeaurora.org> >> --- >> drivers/scsi/ufs/ufshcd.c | 9 +++++---- >> 1 file changed, 5 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c >> index c1c401b..ef155a9 100644 >> --- a/drivers/scsi/ufs/ufshcd.c >> +++ b/drivers/scsi/ufs/ufshcd.c >> @@ -8883,8 +8883,11 @@ int ufshcd_system_suspend(struct ufs_hba *hba) >> int ret = 0; >> ktime_t start = ktime_get(); >> >> + if (!hba) >> + return 0; >> + >> down(&hba->eh_sem); >> - if (!hba || !hba->is_powered) >> + if (!hba->is_powered) >> return 0; > > > Can, > > why not moving down(&hba->eh_sem) after "return 0;"? In your way, if hba is not powered, ufshcd_system_suspend() returns 0, which is a successful suspend. When ufshcd_system_resume() is called, if hba is not powered, it goes to out and does up(&hba->eh_sem), which shall cause unbalance to eh_sem. Thanks, Can Guo.
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index c1c401b..ef155a9 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -8883,8 +8883,11 @@ int ufshcd_system_suspend(struct ufs_hba *hba) int ret = 0; ktime_t start = ktime_get(); + if (!hba) + return 0; + down(&hba->eh_sem); - if (!hba || !hba->is_powered) + if (!hba->is_powered) return 0; if ((ufs_get_pm_lvl_to_dev_pwr_mode(hba->spm_lvl) == @@ -8932,10 +8935,8 @@ int ufshcd_system_resume(struct ufs_hba *hba) int ret = 0; ktime_t start = ktime_get(); - if (!hba) { - up(&hba->eh_sem); + if (!hba) return -EINVAL; - } if (!hba->is_powered || pm_runtime_suspended(hba->dev)) /*
During system resume/suspend, hba could be NULL. In this case, do not touch eh_sem. Fixes: 88a92d6ae4fe ("scsi: ufs: Serialize eh_work with system PM events and async scan") Signed-off-by: Can Guo <cang@codeaurora.org> --- drivers/scsi/ufs/ufshcd.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)