From: Stanley Chu <stanley.chu@mediatek.com>
To: <linux-scsi@vger.kernel.org>, <martin.petersen@oracle.com>,
<avri.altman@wdc.com>, <alim.akhtar@samsung.com>,
<jejb@linux.ibm.com>
Cc: <beanhuo@micron.com>, <asutoshd@codeaurora.org>,
<cang@codeaurora.org>, <matthias.bgg@gmail.com>,
<bvanassche@acm.org>, <linux-mediatek@lists.infradead.org>,
<linux-arm-kernel@lists.infradead.org>,
<linux-kernel@vger.kernel.org>, <kuohong.wang@mediatek.com>,
<peter.wang@mediatek.com>, <chun-hung.wu@mediatek.com>,
<andy.teng@mediatek.com>, <cc.chou@mediatek.com>,
<chaotian.jing@mediatek.com>, <pengshun.zhao@mediatek.com>,
Stanley Chu <stanley.chu@mediatek.com>
Subject: [PATCH v2 1/5] scsi: ufs-mediatek: Fix imprecise waiting time for ref-clk control
Date: Fri, 29 May 2020 17:23:06 +0800 [thread overview]
Message-ID: <20200529092310.1106-2-stanley.chu@mediatek.com> (raw)
In-Reply-To: <20200529092310.1106-1-stanley.chu@mediatek.com>
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 <stanley.chu@mediatek.com>
Reviewed-by: Andy Teng <andy.teng@mediatek.com>
---
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
next prev parent reply other threads:[~2020-05-29 9:23 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-29 9:23 [PATCH v2 0/5] scsi: ufs-mediatek: Fix clk-gating and introduce low-power mode for vccq2 Stanley Chu
2020-05-29 9:23 ` Stanley Chu [this message]
2020-05-31 7:10 ` [PATCH v2 1/5] scsi: ufs-mediatek: Fix imprecise waiting time for ref-clk control Avri Altman
2020-05-31 13:45 ` Stanley Chu
2020-05-29 9:23 ` [PATCH v2 2/5] scsi: ufs-mediatek: Do not gate clocks if auto-hibern8 is not entered yet Stanley Chu
2020-05-29 9:23 ` [PATCH v2 3/5] scsi: ufs-mediatek: Introduce low-power mode for device power supply Stanley Chu
2020-05-29 9:23 ` [PATCH v2 4/5] scsi: ufs-mediatek: Fix unbalanced clock on/off Stanley Chu
2020-05-29 9:23 ` [PATCH v2 5/5] scsi: ufs-mediatek: Allow unbound mphy Stanley Chu
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