linux-kernel - [PATCH 3/3] scsi: ufs: Use freq table with devfreq

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Date:   Mon, 23 Apr 2018 17:20:16 -0700
From:   Bjorn Andersson <bjorn.andersson@...aro.org>
To:     Vinayak Holikatti <vinholikatti@...il.com>,
        "James E.J. Bottomley" <jejb@...ux.vnet.ibm.com>,
        "Martin K. Petersen" <martin.petersen@...cle.com>
Cc:     MyungJoo Ham <myungjoo.ham@...sung.com>,
        Kyungmin Park <kyungmin.park@...sung.com>,
        Chanwoo Choi <cw00.choi@...sung.com>,
        linux-scsi@...r.kernel.org, linux-pm@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-arm-msm@...r.kernel.org,
        Vivek Gautam <vivek.gautam@...eaurora.org>
Subject: [PATCH 3/3] scsi: ufs: Use freq table with devfreq

devfreq requires that the client operates on actual frequencies, not
only 0 and UMAX_INT and as such UFS brok with the introduction of
f1d981eaecf8 ("PM / devfreq: Use the available min/max frequency").

This patch registers the frequencies of the first clock with devfreq and
use these to determine if we're trying to step up or down.

Signed-off-by: Bjorn Andersson <bjorn.andersson@...aro.org>
---
 drivers/scsi/ufs/ufshcd.c | 39 ++++++++++++++++++++++++++++++++-------
 1 file changed, 32 insertions(+), 7 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 2253f24309ec..07b1f3c7bd2d 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -1168,16 +1168,13 @@ static int ufshcd_devfreq_target(struct device *dev,
 	struct ufs_hba *hba = dev_get_drvdata(dev);
 	ktime_t start;
 	bool scale_up, sched_clk_scaling_suspend_work = false;
+	struct list_head *clk_list = &hba->clk_list_head;
+	struct ufs_clk_info *clki;
 	unsigned long irq_flags;
 
 	if (!ufshcd_is_clkscaling_supported(hba))
 		return -EINVAL;
 
-	if ((*freq > 0) && (*freq < UINT_MAX)) {
-		dev_err(hba->dev, "%s: invalid freq = %lu\n", __func__, *freq);
-		return -EINVAL;
-	}
-
 	spin_lock_irqsave(hba->host->host_lock, irq_flags);
 	if (ufshcd_eh_in_progress(hba)) {
 		spin_unlock_irqrestore(hba->host->host_lock, irq_flags);
@@ -1187,7 +1184,13 @@ static int ufshcd_devfreq_target(struct device *dev,
 	if (!hba->clk_scaling.active_reqs)
 		sched_clk_scaling_suspend_work = true;
 
-	scale_up = (*freq == UINT_MAX) ? true : false;
+	if (list_empty(clk_list)) {
+		spin_unlock_irqrestore(hba->host->host_lock, irq_flags);
+		goto out;
+	}
+
+	clki = list_first_entry(&hba->clk_list_head, struct ufs_clk_info, list);
+	scale_up = (*freq == clki->max_freq) ? true : false;
 	if (!ufshcd_is_devfreq_scaling_required(hba, scale_up)) {
 		spin_unlock_irqrestore(hba->host->host_lock, irq_flags);
 		ret = 0;
@@ -1257,11 +1260,33 @@ static struct devfreq_dev_profile ufs_devfreq_profile = {
 
 static int ufshcd_devfreq_init(struct ufs_hba *hba)
 {
+	struct devfreq_dev_profile *profile;
+	struct list_head *clk_list = &hba->clk_list_head;
+	struct ufs_clk_info *clki;
 	struct devfreq *devfreq;
 	int ret;
 
+	/* Skip devfreq if we don't have any clocks in the list */
+	if (list_empty(clk_list))
+		return 0;
+
+	profile = devm_kmemdup(hba->dev, &ufs_devfreq_profile,
+			       sizeof(ufs_devfreq_profile), GFP_KERNEL);
+	if (!profile)
+		return -ENOMEM;
+
+	profile->max_state = 2;
+	profile->freq_table = devm_kcalloc(hba->dev, profile->max_state,
+					   sizeof(unsigned long), GFP_KERNEL);
+	if (!profile->freq_table)
+		return -ENOMEM;
+
+	clki = list_first_entry(&hba->clk_list_head, struct ufs_clk_info, list);
+	profile->freq_table[0] = clki->min_freq;
+	profile->freq_table[1] = clki->max_freq;
+
 	devfreq = devm_devfreq_add_device(hba->dev,
-			&ufs_devfreq_profile,
+			profile,
 			"simple_ondemand",
 			NULL);
 	if (IS_ERR(devfreq)) {
-- 
2.16.2