[PATCH v1 1/1] scsi: ufshcd: Allow zero value setting to Auto-Hibernate Timer

[Bao D. Nguyen]

The zero value Auto-Hibernate Timer is a valid setting, and it
indicates the Auto-Hibernate feature being disabled. Correctly
support this setting. In addition, when this value is queried
from sysfs, read from the host controller's register and return
that value instead of using the RAM value.

Signed-off-by: Bao D. Nguyen <nguyenb@xxxxxxxxxxxxxx>
Signed-off-by: Asutosh Das <asutoshd@xxxxxxxxxxxxxx>
Signed-off-by: Can Guo <cang@xxxxxxxxxxxxxx>
---
 drivers/scsi/ufs/ufs-sysfs.c | 9 ++++++++-
 drivers/scsi/ufs/ufshcd.c    | 2 +-
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/ufs/ufs-sysfs.c b/drivers/scsi/ufs/ufs-sysfs.c
index 02d379f00..bdcd27f 100644
--- a/drivers/scsi/ufs/ufs-sysfs.c
+++ b/drivers/scsi/ufs/ufs-sysfs.c
@@ -146,12 +146,19 @@ static u32 ufshcd_us_to_ahit(unsigned int timer)
 static ssize_t auto_hibern8_show(struct device *dev,
 				 struct device_attribute *attr, char *buf)
 {
+	u32 ahit;
 	struct ufs_hba *hba = dev_get_drvdata(dev);
 
 	if (!ufshcd_is_auto_hibern8_supported(hba))
 		return -EOPNOTSUPP;
 
-	return snprintf(buf, PAGE_SIZE, "%d\n", ufshcd_ahit_to_us(hba->ahit));
+	pm_runtime_get_sync(hba->dev);
+	ufshcd_hold(hba, false);
+	ahit = ufshcd_readl(hba, REG_AUTO_HIBERNATE_IDLE_TIMER);
+	ufshcd_release(hba);
+	pm_runtime_put_sync(hba->dev);
+
+	return scnprintf(buf, PAGE_SIZE, "%d\n", ufshcd_ahit_to_us(ahit));
 }
 
 static ssize_t auto_hibern8_store(struct device *dev,
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 06e2439..ea5cc33 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -3975,7 +3975,7 @@ void ufshcd_auto_hibern8_enable(struct ufs_hba *hba)
 {
 	unsigned long flags;
 
-	if (!ufshcd_is_auto_hibern8_supported(hba) || !hba->ahit)
+	if (!ufshcd_is_auto_hibern8_supported(hba))
 		return;
 
 	spin_lock_irqsave(hba->host->host_lock, flags);
-- 
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