scsi: ufs: Let devices remain runtime suspended during system suspend

If the UFS Device WLUN is runtime suspended and is in the same power mode,
link state, and b_rpm_dev_flush_capable (BKOP or WB buffer flush etc)
state, then it can remain runtime suspended instead of being runtime
resumed and then system suspended.

The following patch has cleared the way for that to happen:

  scsi: core: pm: Only runtime resume if necessary

So amend the logic accordingly.

Note, the ufs-hisi driver uses different RPM and SPM, but it is made
explicit by a new parameter to suspend prepare.

Link: https://lore.kernel.org/r/20211027130614.406985-2-adrian.hunter@intel.com
Reviewed-by: Asutosh Das <asutoshd@codeaurora.org>
Reviewed-by: Bean Huo <beanhuo@micron.com>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/ufs/ufs-hisi.c b/drivers/scsi/ufs/ufs-hisi.c
index 8c7e8d3217462f0a12137aea40159c40d00901c3..ab1a7ebd89b1ce808ead593ace5d068eaf6f88da 100644 (file)
--- a/drivers/scsi/ufs/ufs-hisi.c
+++ b/drivers/scsi/ufs/ufs-hisi.c
@@ -396,6 +396,12 @@ out:
        return ret;
 }
 
+static int ufs_hisi_suspend_prepare(struct device *dev)
+{
+       /* RPM and SPM are different. Refer ufs_hisi_suspend() */
+       return __ufshcd_suspend_prepare(dev, false);
+}
+
 static int ufs_hisi_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op,
        enum ufs_notify_change_status status)
 {
@@ -578,7 +584,7 @@ static int ufs_hisi_remove(struct platform_device *pdev)
 static const struct dev_pm_ops ufs_hisi_pm_ops = {
        SET_SYSTEM_SLEEP_PM_OPS(ufshcd_system_suspend, ufshcd_system_resume)
        SET_RUNTIME_PM_OPS(ufshcd_runtime_suspend, ufshcd_runtime_resume, NULL)
-       .prepare         = ufshcd_suspend_prepare,
+       .prepare         = ufs_hisi_suspend_prepare,
        .complete        = ufshcd_resume_complete,
 };
 

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index afd38142b1c0282f6db4c410c06ce8684c98622c..024f6d95834131b0d75aad64a1602b659f03c569 100644 (file)
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -9708,7 +9708,27 @@ void ufshcd_resume_complete(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(ufshcd_resume_complete);
 
-int ufshcd_suspend_prepare(struct device *dev)
+static bool ufshcd_rpm_ok_for_spm(struct ufs_hba *hba)
+{
+       struct device *dev = &hba->sdev_ufs_device->sdev_gendev;
+       enum ufs_dev_pwr_mode dev_pwr_mode;
+       enum uic_link_state link_state;
+       unsigned long flags;
+       bool res;
+
+       spin_lock_irqsave(&dev->power.lock, flags);
+       dev_pwr_mode = ufs_get_pm_lvl_to_dev_pwr_mode(hba->spm_lvl);
+       link_state = ufs_get_pm_lvl_to_link_pwr_state(hba->spm_lvl);
+       res = pm_runtime_suspended(dev) &&
+             hba->curr_dev_pwr_mode == dev_pwr_mode &&
+             hba->uic_link_state == link_state &&
+             !hba->dev_info.b_rpm_dev_flush_capable;
+       spin_unlock_irqrestore(&dev->power.lock, flags);
+
+       return res;
+}
+
+int __ufshcd_suspend_prepare(struct device *dev, bool rpm_ok_for_spm)
 {
        struct ufs_hba *hba = dev_get_drvdata(dev);
        int ret;
@@ -9720,15 +9740,30 @@ int ufshcd_suspend_prepare(struct device *dev)
         * Refer ufshcd_resume_complete()
         */
        if (hba->sdev_ufs_device) {
-               ret = ufshcd_rpm_get_sync(hba);
-               if (ret < 0 && ret != -EACCES) {
-                       ufshcd_rpm_put(hba);
-                       return ret;
+               /* Prevent runtime suspend */
+               ufshcd_rpm_get_noresume(hba);
+               /*
+                * Check if already runtime suspended in same state as system
+                * suspend would be.
+                */
+               if (!rpm_ok_for_spm || !ufshcd_rpm_ok_for_spm(hba)) {
+                       /* RPM state is not ok for SPM, so runtime resume */
+                       ret = ufshcd_rpm_resume(hba);
+                       if (ret < 0 && ret != -EACCES) {
+                               ufshcd_rpm_put(hba);
+                               return ret;
+                       }
                }
                hba->complete_put = true;
        }
        return 0;
 }
+EXPORT_SYMBOL_GPL(__ufshcd_suspend_prepare);
+
+int ufshcd_suspend_prepare(struct device *dev)
+{
+       return __ufshcd_suspend_prepare(dev, true);
+}
 EXPORT_SYMBOL_GPL(ufshcd_suspend_prepare);
 
 #ifdef CONFIG_PM_SLEEP

diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 54750d72c8fb095b09a07852dd06c74907677c19..6103e98e9a088c18c3028d04c9af4fc28c032e42 100644 (file)
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -1211,6 +1211,7 @@ int ufshcd_exec_raw_upiu_cmd(struct ufs_hba *hba,
 
 int ufshcd_wb_toggle(struct ufs_hba *hba, bool enable);
 int ufshcd_suspend_prepare(struct device *dev);
+int __ufshcd_suspend_prepare(struct device *dev, bool rpm_ok_for_spm);
 void ufshcd_resume_complete(struct device *dev);
 
 /* Wrapper functions for safely calling variant operations */
@@ -1420,6 +1421,16 @@ static inline int ufshcd_rpm_put_sync(struct ufs_hba *hba)
        return pm_runtime_put_sync(&hba->sdev_ufs_device->sdev_gendev);
 }
 
+static inline void ufshcd_rpm_get_noresume(struct ufs_hba *hba)
+{
+       pm_runtime_get_noresume(&hba->sdev_ufs_device->sdev_gendev);
+}
+
+static inline int ufshcd_rpm_resume(struct ufs_hba *hba)
+{
+       return pm_runtime_resume(&hba->sdev_ufs_device->sdev_gendev);
+}
+
 static inline int ufshcd_rpm_put(struct ufs_hba *hba)
 {
        return pm_runtime_put(&hba->sdev_ufs_device->sdev_gendev);