scsi: Revert "scsi: ufs: core: Initialize devfreq synchronously"

This reverts commit 7dafc3e.

This patch introduced a regression [1] where hba->pwr_info is used before
being initialized, which could create issues in ufshcd_scale_gear(). Revert
it until a better solution is found.

[1] https://lore.kernel.org/all/CAGaU9a_PMZhqv+YJ0r3w-hJMsR922oxW6Kg59vw+oen-NZ6Otw@mail.gmail.com

Signed-off-by: Adrien Thierry <athierry@redhat.com>
Link: https://lore.kernel.org/r/20230329205426.46393-1-athierry@redhat.com
Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/ufs/core/ufshcd.c

@@ -1409,13 +1409,6 @@ static int ufshcd_devfreq_target(struct device *dev,
 	struct ufs_clk_info *clki;
 	unsigned long irq_flags;
 
-	/*
-	 * Skip devfreq if UFS initialization is not finished.
-	 * Otherwise ufs could be in a inconsistent state.
-	 */
-	if (!smp_load_acquire(&hba->logical_unit_scan_finished))
-		return 0;
-
 	if (!ufshcd_is_clkscaling_supported(hba))
 		return -EINVAL;
 
@@ -8399,6 +8392,22 @@ static int ufshcd_add_lus(struct ufs_hba *hba)
 	if (ret)
 		goto out;
 
+	/* Initialize devfreq after UFS device is detected */
+	if (ufshcd_is_clkscaling_supported(hba)) {
+		memcpy(&hba->clk_scaling.saved_pwr_info.info,
+			&hba->pwr_info,
+			sizeof(struct ufs_pa_layer_attr));
+		hba->clk_scaling.saved_pwr_info.is_valid = true;
+		hba->clk_scaling.is_allowed = true;
+
+		ret = ufshcd_devfreq_init(hba);
+		if (ret)
+			goto out;
+
+		hba->clk_scaling.is_enabled = true;
+		ufshcd_init_clk_scaling_sysfs(hba);
+	}
+
 	ufs_bsg_probe(hba);
 	ufshpb_init(hba);
 	scsi_scan_host(hba->host);
@@ -8670,12 +8679,6 @@ static void ufshcd_async_scan(void *data, async_cookie_t cookie)
 	if (ret) {
 		pm_runtime_put_sync(hba->dev);
 		ufshcd_hba_exit(hba);
-	} else {
-		/*
-		 * Make sure that when reader code sees UFS initialization has finished,
-		 * all initialization steps have really been executed.
-		 */
-		smp_store_release(&hba->logical_unit_scan_finished, true);
 	}
 }
 
@@ -10316,30 +10319,12 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq)
 	 */
 	ufshcd_set_ufs_dev_active(hba);
 
-	/* Initialize devfreq */
-	if (ufshcd_is_clkscaling_supported(hba)) {
-		memcpy(&hba->clk_scaling.saved_pwr_info.info,
-			&hba->pwr_info,
-			sizeof(struct ufs_pa_layer_attr));
-		hba->clk_scaling.saved_pwr_info.is_valid = true;
-		hba->clk_scaling.is_allowed = true;
-
-		err = ufshcd_devfreq_init(hba);
-		if (err)
-			goto rpm_put_sync;
-
-		hba->clk_scaling.is_enabled = true;
-		ufshcd_init_clk_scaling_sysfs(hba);
-	}
-
 	async_schedule(ufshcd_async_scan, hba);
 	ufs_sysfs_add_nodes(hba->dev);
 
 	device_enable_async_suspend(dev);
 	return 0;
 
-rpm_put_sync:
-	pm_runtime_put_sync(dev);
 free_tmf_queue:
 	blk_mq_destroy_queue(hba->tmf_queue);
 	blk_put_queue(hba->tmf_queue);

include/ufs/ufshcd.h

@@ -979,7 +979,6 @@ struct ufs_hba {
 	struct completion *uic_async_done;
 
 	enum ufshcd_state ufshcd_state;
-	bool logical_unit_scan_finished;
 	u32 eh_flags;
 	u32 intr_mask;
 	u16 ee_ctrl_mask;