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Subject[PATCH v6 1/2] scsi: ufs: Clean up ufshcd_scale_clks() and clock scaling error out path
Date
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.

Fixes: a3cd5ec55f6c ("scsi: ufs: add load based scaling of UFS gear")
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: Can Guo <cang@codeaurora.org>
---
drivers/scsi/ufs/ufshcd.c | 65 ++++++++++++++++++++++++++++++++---------------
1 file changed, 44 insertions(+), 21 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 2a2a63b..148e73a 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",
@@ -914,11 +914,37 @@ 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;
+ ktime_t start = ktime_get();
+
+ ret = ufshcd_vops_clk_scale_notify(hba, scale_up, PRE_CHANGE);
+ if (ret)
+ goto out;
+
+ ret = ufshcd_set_clk_freq(hba, scale_up);
+ if (ret)
+ goto out;
+
ret = ufshcd_vops_clk_scale_notify(hba, scale_up, POST_CHANGE);
+ if (ret)
+ ufshcd_set_clk_freq(hba, !scale_up);

out:
- if (clk_state_changed)
- trace_ufshcd_profile_clk_scaling(dev_name(hba->dev),
+ 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 +1132,32 @@ 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 out_unprepare;
}

ret = ufshcd_scale_clks(hba, scale_up);
if (ret) {
if (!scale_up)
ufshcd_scale_gear(hba, true);
- goto out;
+ goto out_unprepare;
}

/* scale up the gear after scaling up clocks */
if (scale_up) {
ret = ufshcd_scale_gear(hba, true);
- if (ret) {
+ if (ret)
ufshcd_scale_clks(hba, false);
- goto out;
- }
}

- ret = ufshcd_vops_clk_scale_notify(hba, scale_up, POST_CHANGE);
-
-out:
+out_unprepare:
ufshcd_clock_scaling_unprepare(hba);
+out:
ufshcd_release(hba);
return ret;
}
@@ -6251,7 +6274,7 @@ 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)
--
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.
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