Messages in this thread | | | Date | Fri, 18 Dec 2020 13:42:35 +0800 | From | Can Guo <> | Subject | Re: [PATCH V2 1/1] scsi: ufs: Fix a possible NULL pointer issue |
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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.
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