[PATCH 1/2] scsi: ufs: Clean up ufshcd_scale_clks() and clock scaling error out path

* [PATCH 1/2] scsi: ufs: Clean up ufshcd_scale_clks() and clock scaling error out path
       [not found] <1584339655-20337-1-git-send-email-cang@codeaurora.org>
@ 2020-03-16  6:20 ` Can Guo
  2020-03-16  6:20 ` [PATCH 2/2] scsi: ufs: Do not rely on prefetched data Can Guo
  1 sibling, 0 replies; 5+ messages in thread
From: Can Guo @ 2020-03-16  6:20 UTC (permalink / raw)
  To: asutoshd, nguyenb, hongwus, rnayak, linux-scsi, kernel-team,
	saravanak, salyzyn, cang
  Cc: Subhash Jadavani, Alim Akhtar, Avri Altman, James E.J. Bottomley,
	Martin K. Petersen, Stanley Chu, Bean Huo, Bart Van Assche,
	Venkat Gopalakrishnan, Tomas Winkler, open list

From: Subhash Jadavani <subhashj@codeaurora.org>

This change introduces a func ufshcd_set_clk_freq() to explicitly
set clock frequency so that it can be used in reset_and_resotre path and
in ufshcd_scale_clks(). Meanwhile, this change cleans up the clock scaling
error out path.

Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: Can Guo <cang@codeaurora.org>

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 2a2a63b..63aaa88f 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -855,28 +855,29 @@ static bool ufshcd_is_unipro_pa_params_tuning_req(struct ufs_hba *hba)
 		return false;
 }
 
-static int ufshcd_scale_clks(struct ufs_hba *hba, bool scale_up)
+/**
+ * ufshcd_set_clk_freq - set UFS controller clock frequencies
+ * @hba: per adapter instance
+ * @scale_up: If True, set max possible frequency othewise set low frequency
+ *
+ * Returns 0 if successful
+ * Returns < 0 for any other errors
+ */
+static int ufshcd_set_clk_freq(struct ufs_hba *hba, bool scale_up)
 {
 	int ret = 0;
 	struct ufs_clk_info *clki;
 	struct list_head *head = &hba->clk_list_head;
-	ktime_t start = ktime_get();
-	bool clk_state_changed = false;
 
 	if (list_empty(head))
 		goto out;
 
-	ret = ufshcd_vops_clk_scale_notify(hba, scale_up, PRE_CHANGE);
-	if (ret)
-		return ret;
-
 	list_for_each_entry(clki, head, list) {
 		if (!IS_ERR_OR_NULL(clki->clk)) {
 			if (scale_up && clki->max_freq) {
 				if (clki->curr_freq == clki->max_freq)
 					continue;
 
-				clk_state_changed = true;
 				ret = clk_set_rate(clki->clk, clki->max_freq);
 				if (ret) {
 					dev_err(hba->dev, "%s: %s clk set rate(%dHz) failed, %d\n",
@@ -895,7 +896,6 @@ static int ufshcd_scale_clks(struct ufs_hba *hba, bool scale_up)
 				if (clki->curr_freq == clki->min_freq)
 					continue;
 
-				clk_state_changed = true;
 				ret = clk_set_rate(clki->clk, clki->min_freq);
 				if (ret) {
 					dev_err(hba->dev, "%s: %s clk set rate(%dHz) failed, %d\n",
@@ -914,13 +914,36 @@ static int ufshcd_scale_clks(struct ufs_hba *hba, bool scale_up)
 				clki->name, clk_get_rate(clki->clk));
 	}
 
+out:
+	return ret;
+}
+
+/**
+ * ufshcd_scale_clks - scale up or scale down UFS controller clocks
+ * @hba: per adapter instance
+ * @scale_up: True if scaling up and false if scaling down
+ *
+ * Returns 0 if successful
+ * Returns < 0 for any other errors
+ */
+static int ufshcd_scale_clks(struct ufs_hba *hba, bool scale_up)
+{
+	int ret = 0;
+
+	ret = ufshcd_vops_clk_scale_notify(hba, scale_up, PRE_CHANGE);
+	if (ret)
+		return ret;
+
+	ret = ufshcd_set_clk_freq(hba, scale_up);
+	if (ret)
+		return ret;
+
 	ret = ufshcd_vops_clk_scale_notify(hba, scale_up, POST_CHANGE);
+	if (ret) {
+		ufshcd_set_clk_freq(hba, !scale_up);
+		return ret;
+	}
 
-out:
-	if (clk_state_changed)
-		trace_ufshcd_profile_clk_scaling(dev_name(hba->dev),
-			(scale_up ? "up" : "down"),
-			ktime_to_us(ktime_sub(ktime_get(), start)), ret);
 	return ret;
 }
 
@@ -1106,35 +1129,36 @@ static int ufshcd_devfreq_scale(struct ufs_hba *hba, bool scale_up)
 
 	ret = ufshcd_clock_scaling_prepare(hba);
 	if (ret)
-		return ret;
+		goto out;
 
 	/* scale down the gear before scaling down clocks */
 	if (!scale_up) {
 		ret = ufshcd_scale_gear(hba, false);
 		if (ret)
-			goto out;
+			goto clk_scaling_unprepare;
 	}
 
 	ret = ufshcd_scale_clks(hba, scale_up);
-	if (ret) {
-		if (!scale_up)
-			ufshcd_scale_gear(hba, true);
-		goto out;
-	}
+	if (ret)
+		goto scale_up_gear;
 
 	/* scale up the gear after scaling up clocks */
 	if (scale_up) {
 		ret = ufshcd_scale_gear(hba, true);
 		if (ret) {
 			ufshcd_scale_clks(hba, false);
-			goto out;
+			goto clk_scaling_unprepare;
 		}
 	}
 
-	ret = ufshcd_vops_clk_scale_notify(hba, scale_up, POST_CHANGE);
+	goto clk_scaling_unprepare;
 
-out:
+scale_up_gear:
+	if (!scale_up)
+		ufshcd_scale_gear(hba, true);
+clk_scaling_unprepare:
 	ufshcd_clock_scaling_unprepare(hba);
+out:
 	ufshcd_release(hba);
 	return ret;
 }
@@ -6251,7 +6275,7 @@ static int ufshcd_host_reset_and_restore(struct ufs_hba *hba)
 	spin_unlock_irqrestore(hba->host->host_lock, flags);
 
 	/* scale up clocks to max frequency before full reinitialization */
-	ufshcd_scale_clks(hba, true);
+	ufshcd_set_clk_freq(hba, true);
 
 	err = ufshcd_hba_enable(hba);
 	if (err)
-- 
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