Messages in this thread | | | Date | Tue, 05 Jan 2021 09:10:05 +0800 | From | Can Guo <> | Subject | Re: [PATCH v2 3/3] scsi: ufs: Let resume callback return -EBUSY after ufshcd_shutdown |
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On 2020-12-25 01:20, Bean Huo wrote: > From: Bean Huo <beanhuo@micron.com> > > After ufshcd_shutdown(), both UFS device and UFS LINk are powered off, > return '0' will mislead the upper PM layer since the device has not > been > successfully resumed yet. This will let pm_runtime_get_sync() caller > mistakenly believe the device/LINK has been resumed, which leads to > request processing timeout that was en-queued later. > > To fix this, let ufshcd_system/runtimie_resume() return -EBUSY in case > of > hba->is_powered == false.
This change won't work as you expect...
During/after shutdown, for UFS's case only, pm_runtime_get_sync(hba->dev) will most likely return 0, because it is already RUNTIME_ACTIVE, pm_runtime_get_sync() will directly return 0... meaning your change won't even be exercised.
Check Stanley's change - https://lore.kernel.org/patchwork/patch/1341389/
Can Guo.
> > Signed-off-by: Bean Huo <beanhuo@micron.com> > --- > drivers/scsi/ufs/ufshcd.c | 12 ++++++++---- > 1 file changed, 8 insertions(+), 4 deletions(-) > > diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c > index e221add25a7e..e1bcac51c01f 100644 > --- a/drivers/scsi/ufs/ufshcd.c > +++ b/drivers/scsi/ufs/ufshcd.c > @@ -8950,14 +8950,16 @@ int ufshcd_system_resume(struct ufs_hba *hba) > return -EINVAL; > } > > - if (!hba->is_powered || pm_runtime_suspended(hba->dev)) > + if (!hba->is_powered || pm_runtime_suspended(hba->dev)) { > /* > * Let the runtime resume take care of resuming > * if runtime suspended. > */ > + ret = -EBUSY; > goto out; > - else > + } else { > ret = ufshcd_resume(hba, UFS_SYSTEM_PM); > + } > out: > trace_ufshcd_system_resume(dev_name(hba->dev), ret, > ktime_to_us(ktime_sub(ktime_get(), start)), > @@ -9026,10 +9028,12 @@ int ufshcd_runtime_resume(struct ufs_hba *hba) > if (!hba) > return -EINVAL; > > - if (!hba->is_powered) > + if (!hba->is_powered) { > + ret = -EBUSY; > goto out; > - else > + } else { > ret = ufshcd_resume(hba, UFS_RUNTIME_PM); > + } > out: > trace_ufshcd_runtime_resume(dev_name(hba->dev), ret, > ktime_to_us(ktime_sub(ktime_get(), start)),
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