Re: [PATCH v20 1/2] scsi: ufs: Enable power management for wlun

From: Asutosh Das (asd)
Date: Fri Apr 23 2021 - 19:44:58 EST

On 4/23/2021 1:01 AM, Adrian Hunter wrote:

Hi Adrian,
Thanks for the help.
I made the changes and tried to reproduce it.
My setup becomes non-responsive and resets.
I don't think it's related to this issue though.

I hadn't set rpm_lvl and spm_lvl to 0 while testing the other day.
Setting those to 0, it proceeds further and now it becomes unresponsive. So I still don't clearly see the issue that you're seeing. However, I'd make the suggested changes and push it in next version.

I think we also need to runtime resume RPMB WLUN before system suspend.

+static int ufshcd_rpmb_rpm_get_sync(struct ufs_hba *hba)
+ return pm_runtime_get_sync(&hba->sdev_rpmb->sdev_gendev);
+static int ufshcd_rpmb_rpm_put(struct ufs_hba *hba)
+ return pm_runtime_put(&hba->sdev_rpmb->sdev_gendev);
void ufshcd_resume_complete(struct device *dev)
struct ufs_hba *hba = dev_get_drvdata(dev);
+ if (hba->rpmb_complete_put) {
+ hba->rpmb_complete_put = false;
+ ufshcd_rpmb_rpm_put(hba);
+ }
if (hba->complete_put) {
hba->complete_put = false;
@@ -9611,6 +9625,11 @@ int ufshcd_suspend_prepare(struct device *dev)
return ret;
hba->complete_put = true;
+ if (hba->sdev_rpmb) {
+ ufshcd_rpmb_rpm_get_sync(hba);
+ hba->rpmb_complete_put = true;
+ }
return 0;

That also avoids another issue: if RPMB WLUN is runtime suspended at system resume, we have to skip clearing UAC, but SCSI PM will force the runtime status to RPM_ACTIVE after system resume, so the UAC never gets cleared in that case.

Furthermore, it seems better not to report errors from RPMB resume and instead let the error handler sort it out.
So, with the above change, we can simplify a bit:

-static int ufshcd_rpmb_runtime_resume(struct device *dev)
- struct ufs_hba *hba = wlun_dev_to_hba(dev);
- if (hba->sdev_rpmb)
- return ufshcd_clear_rpmb_uac(hba);
- return 0;
static int ufshcd_rpmb_resume(struct device *dev)
struct ufs_hba *hba = wlun_dev_to_hba(dev);
- if (hba->sdev_rpmb && !pm_runtime_suspended(dev))
- return ufshcd_clear_rpmb_uac(hba);
+ if (hba->sdev_rpmb)
+ ufshcd_clear_rpmb_uac(hba);
return 0;
static const struct dev_pm_ops ufs_rpmb_pm_ops = {
- SET_RUNTIME_PM_OPS(NULL, ufshcd_rpmb_runtime_resume, NULL)
+ SET_RUNTIME_PM_OPS(NULL, ufshcd_rpmb_resume, NULL)
SET_SYSTEM_SLEEP_PM_OPS(NULL, ufshcd_rpmb_resume)

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