On 2020-03-18 16:19, Avri Altman wrote:
Hi,
From: Subhash Jadavani <subhashj@xxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxx>
Signed-off-by: Can Guo <cang@xxxxxxxxxxxxxx>
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)
Personally I prefer using the convention of "__scale_clks" to describe
the privet core of scale_clks,
But I know that many people are against it.
{
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);
Why remove the ufshcd_profile_clk_scaling trace?
Shall add it back, this is just a collection of Subhash's changes.
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;
Are you fixing here a hold without release?
Should make note of that.
Yes, true
/* 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;
I think you should find a way to make this function more readable.
Adding all those "spaghetti" gotos making it even harder to read.
Thanks,
Avri
This is just a collection of Subhash's changes. I think the 2
clk_scaling_unprepare and out gotos make sense, but the
scale_up_gear goto is a bit vague. I will remove the
scale_up_gear goto.
Thanks,
Can Guo.
-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)
--
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a
Linux Foundation Collaborative Project.
