scsi: ufs: core: Add missing post notify for power mode change

BugLink: https://bugs.launchpad.net/bugs/2102118

commit 7f45ed5 upstream.

When the power mode change is successful but the power mode hasn't
actually changed, the post notification was missed.  Similar to the
approach with hibernate/clock scale/hce enable, having pre/post
notifications in the same function will make it easier to maintain.

Additionally, supplement the description of power parameters for the
pwr_change_notify callback.

Fixes: 7eb584d ("ufs: refactor configuring power mode")
Cc: stable@vger.kernel.org #6.11.x
Signed-off-by: Peter Wang <peter.wang@mediatek.com>
Link: https://lore.kernel.org/r/20241122024943.30589-1-peter.wang@mediatek.com
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Koichiro Den <koichiro.den@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

Author: ptr324

drivers/ufs/core/ufshcd.c

@@ -4655,9 +4655,6 @@ static int ufshcd_change_power_mode(struct ufs_hba *hba,
 		dev_err(hba->dev,
 			"%s: power mode change failed %d\n", __func__, ret);
 	} else {
-		ufshcd_vops_pwr_change_notify(hba, POST_CHANGE, NULL,
-								pwr_mode);
-
 		memcpy(&hba->pwr_info, pwr_mode,
 			sizeof(struct ufs_pa_layer_attr));
 	}
@@ -4686,6 +4683,10 @@ int ufshcd_config_pwr_mode(struct ufs_hba *hba,
 
 	ret = ufshcd_change_power_mode(hba, &final_params);
 
+	if (!ret)
+		ufshcd_vops_pwr_change_notify(hba, POST_CHANGE, NULL,
+					&final_params);
+
 	return ret;
 }
 EXPORT_SYMBOL_GPL(ufshcd_config_pwr_mode);

include/ufs/ufshcd.h

@@ -306,7 +306,9 @@ struct ufs_pwr_mode_info {
  *                       to allow variant specific Uni-Pro initialization.
  * @pwr_change_notify: called before and after a power mode change
  *			is carried out to allow vendor spesific capabilities
- *			to be set.
+ *			to be set. PRE_CHANGE can modify final_params based
+ *			on desired_pwr_mode, but POST_CHANGE must not alter
+ *			the final_params parameter
  * @setup_xfer_req: called before any transfer request is issued
  *                  to set some things
  * @setup_task_mgmt: called before any task management request is issued
@@ -343,9 +345,9 @@ struct ufs_hba_variant_ops {
 	int	(*link_startup_notify)(struct ufs_hba *,
 				       enum ufs_notify_change_status);
 	int	(*pwr_change_notify)(struct ufs_hba *,
-					enum ufs_notify_change_status status,
-					struct ufs_pa_layer_attr *,
-					struct ufs_pa_layer_attr *);
+				enum ufs_notify_change_status status,
+				struct ufs_pa_layer_attr *desired_pwr_mode,
+				struct ufs_pa_layer_attr *final_params);
 	void	(*setup_xfer_req)(struct ufs_hba *hba, int tag,
 				  bool is_scsi_cmd);
 	void	(*setup_task_mgmt)(struct ufs_hba *, int, u8);