Currently ref-clk control timeout is implemented by Jiffies. However
jiffies is not accurate enough thus "false timeout" may happen.

Use more accurate delay mechanism instead, for example, ktime.

Signed-off-by: Stanley Chu <[email protected]>
Reviewed-by: Andy Teng <[email protected]>
Reviewed-by: Avri Altman <[email protected]>
---
 drivers/scsi/ufs/ufs-mediatek.c | 7 ++++---
 drivers/scsi/ufs/ufs-mediatek.h | 2 +-
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-mediatek.c
index d56ce8d97d4e..523ee5573921 100644
--- a/drivers/scsi/ufs/ufs-mediatek.c
+++ b/drivers/scsi/ufs/ufs-mediatek.c
@@ -120,7 +120,7 @@ static int ufs_mtk_setup_ref_clk(struct ufs_hba *hba, bool 
on)
 {
        struct ufs_mtk_host *host = ufshcd_get_variant(hba);
        struct arm_smccc_res res;
-       unsigned long timeout;
+       ktime_t timeout, time_checked;
        u32 value;
 
        if (host->ref_clk_enabled == on)
@@ -135,8 +135,9 @@ static int ufs_mtk_setup_ref_clk(struct ufs_hba *hba, bool 
on)
        }
 
        /* Wait for ack */
-       timeout = jiffies + msecs_to_jiffies(REFCLK_REQ_TIMEOUT_MS);
+       timeout = ktime_add_us(ktime_get(), REFCLK_REQ_TIMEOUT_US);
        do {
+               time_checked = ktime_get();
                value = ufshcd_readl(hba, REG_UFS_REFCLK_CTRL);
 
                /* Wait until ack bit equals to req bit */
@@ -144,7 +145,7 @@ static int ufs_mtk_setup_ref_clk(struct ufs_hba *hba, bool 
on)
                        goto out;
 
                usleep_range(100, 200);
-       } while (time_before(jiffies, timeout));
+       } while (ktime_before(time_checked, timeout));
 
        dev_err(hba->dev, "missing ack of refclk req, reg: 0x%x\n", value);
 
diff --git a/drivers/scsi/ufs/ufs-mediatek.h b/drivers/scsi/ufs/ufs-mediatek.h
index 5bbd3e9cbae2..fc42dcbfd800 100644
--- a/drivers/scsi/ufs/ufs-mediatek.h
+++ b/drivers/scsi/ufs/ufs-mediatek.h
@@ -28,7 +28,7 @@
 #define REFCLK_REQUEST              BIT(0)
 #define REFCLK_ACK                  BIT(1)
 
-#define REFCLK_REQ_TIMEOUT_MS       3
+#define REFCLK_REQ_TIMEOUT_US       3000
 
 /*
  * Vendor specific pre-defined parameters
-- 
2.18.0

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