* [PATCH v1 0/3] scsi: ufs-mediatek: Fix clk-gating and introduce low-power mode for vccq2
@ 2020-05-22 12:18 Stanley Chu
2020-05-22 12:18 ` [PATCH v1 1/3] scsi: ufs-mediatek: Fix imprecise waiting time for ref-clk control Stanley Chu
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: Stanley Chu @ 2020-05-22 12:18 UTC (permalink / raw)
To: linux-scsi, martin.petersen, avri.altman, alim.akhtar, jejb
Cc: beanhuo, asutoshd, cang, matthias.bgg, bvanassche,
linux-mediatek, linux-arm-kernel, linux-kernel, kuohong.wang,
peter.wang, chun-hung.wu, andy.teng, cc.chou, chaotian.jing,
pengshun.zhao, Stanley Chu
Hi,
This patchset fixes a clk-gating issue and introduces low-power mode for vccq2 in MediaTek platforms.
Stanley Chu (3):
scsi: ufs-mediatek: Fix imprecise waiting time for ref-clk control
scsi: ufs-mediatek: Do not gate clocks if auto-hibern8 is not entered
yet
scsi: ufs-mediatek: Introduce low-power mode for device power supply
drivers/scsi/ufs/ufs-mediatek.c | 64 ++++++++++++++++++++++++++-------
drivers/scsi/ufs/ufs-mediatek.h | 2 +-
2 files changed, 53 insertions(+), 13 deletions(-)
--
2.18.0
^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH v1 1/3] scsi: ufs-mediatek: Fix imprecise waiting time for ref-clk control
2020-05-22 12:18 [PATCH v1 0/3] scsi: ufs-mediatek: Fix clk-gating and introduce low-power mode for vccq2 Stanley Chu
@ 2020-05-22 12:18 ` Stanley Chu
2020-05-22 12:18 ` [PATCH v1 2/3] scsi: ufs-mediatek: Do not gate clocks if auto-hibern8 is not entered yet Stanley Chu
2020-05-22 12:18 ` [PATCH v1 3/3] scsi: ufs-mediatek: Introduce low-power mode for device power supply Stanley Chu
2 siblings, 0 replies; 4+ messages in thread
From: Stanley Chu @ 2020-05-22 12:18 UTC (permalink / raw)
To: linux-scsi, martin.petersen, avri.altman, alim.akhtar, jejb
Cc: beanhuo, asutoshd, cang, matthias.bgg, bvanassche,
linux-mediatek, linux-arm-kernel, linux-kernel, kuohong.wang,
peter.wang, chun-hung.wu, andy.teng, cc.chou, chaotian.jing,
pengshun.zhao, Stanley Chu
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
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH v1 2/3] scsi: ufs-mediatek: Do not gate clocks if auto-hibern8 is not entered yet
2020-05-22 12:18 [PATCH v1 0/3] scsi: ufs-mediatek: Fix clk-gating and introduce low-power mode for vccq2 Stanley Chu
2020-05-22 12:18 ` [PATCH v1 1/3] scsi: ufs-mediatek: Fix imprecise waiting time for ref-clk control Stanley Chu
@ 2020-05-22 12:18 ` Stanley Chu
2020-05-22 12:18 ` [PATCH v1 3/3] scsi: ufs-mediatek: Introduce low-power mode for device power supply Stanley Chu
2 siblings, 0 replies; 4+ messages in thread
From: Stanley Chu @ 2020-05-22 12:18 UTC (permalink / raw)
To: linux-scsi, martin.petersen, avri.altman, alim.akhtar, jejb
Cc: beanhuo, asutoshd, cang, matthias.bgg, bvanassche,
linux-mediatek, linux-arm-kernel, linux-kernel, kuohong.wang,
peter.wang, chun-hung.wu, andy.teng, cc.chou, chaotian.jing,
pengshun.zhao, Stanley Chu
There are some chances that link enters hibern8 lately by auto-hibern8
scheme during the clock-gating flow. Clocks shall not be gated if link
is still active otherwise host or device may hang.
Fix this by returning error code to the caller __ufshcd_setup_clocks()
to skip gating clocks there if link is not confirmed in hibern8
state yet.
Also allow some waiting time for the hibern8 state transition.
Signed-off-by: Stanley Chu <stanley.chu@mediatek.com>
Reviewed-by: Andy Teng <andy.teng@mediatek.com>
---
drivers/scsi/ufs/ufs-mediatek.c | 36 ++++++++++++++++++++++++---------
1 file changed, 27 insertions(+), 9 deletions(-)
diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-mediatek.c
index 523ee5573921..3c85f5e97dea 100644
--- a/drivers/scsi/ufs/ufs-mediatek.c
+++ b/drivers/scsi/ufs/ufs-mediatek.c
@@ -178,15 +178,30 @@ static void ufs_mtk_setup_ref_clk_wait_us(struct ufs_hba *hba,
host->ref_clk_ungating_wait_us = ungating_us;
}
-static u32 ufs_mtk_link_get_state(struct ufs_hba *hba)
+int ufs_mtk_wait_link_state(struct ufs_hba *hba, u32 state,
+ unsigned long max_wait_ms)
{
+ ktime_t timeout, time_checked;
u32 val;
- ufshcd_writel(hba, 0x20, REG_UFS_DEBUG_SEL);
- val = ufshcd_readl(hba, REG_UFS_PROBE);
- val = val >> 28;
+ timeout = ktime_add_us(ktime_get(), ms_to_ktime(max_wait_ms));
+ do {
+ time_checked = ktime_get();
+ ufshcd_writel(hba, 0x20, REG_UFS_DEBUG_SEL);
+ val = ufshcd_readl(hba, REG_UFS_PROBE);
+ val = val >> 28;
+
+ if (val == state)
+ return 0;
- return val;
+ /* Sleep for max. 200us */
+ usleep_range(100, 200);
+ } while (ktime_before(time_checked, timeout));
+
+ if (val == state)
+ return 0;
+
+ return -ETIMEDOUT;
}
/**
@@ -221,10 +236,13 @@ static int ufs_mtk_setup_clocks(struct ufs_hba *hba, bool on,
* triggered by Auto-Hibern8.
*/
if (!ufshcd_can_hibern8_during_gating(hba) &&
- ufshcd_is_auto_hibern8_enabled(hba) &&
- ufs_mtk_link_get_state(hba) ==
- VS_LINK_HIBERN8)
- ufs_mtk_setup_ref_clk(hba, on);
+ ufshcd_is_auto_hibern8_enabled(hba)) {
+ ret = ufs_mtk_wait_link_state(hba,
+ VS_LINK_HIBERN8,
+ 15);
+ if (!ret)
+ ufs_mtk_setup_ref_clk(hba, on);
+ }
}
} else if (on && status == POST_CHANGE) {
ret = phy_power_on(host->mphy);
--
2.18.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH v1 3/3] scsi: ufs-mediatek: Introduce low-power mode for device power supply
2020-05-22 12:18 [PATCH v1 0/3] scsi: ufs-mediatek: Fix clk-gating and introduce low-power mode for vccq2 Stanley Chu
2020-05-22 12:18 ` [PATCH v1 1/3] scsi: ufs-mediatek: Fix imprecise waiting time for ref-clk control Stanley Chu
2020-05-22 12:18 ` [PATCH v1 2/3] scsi: ufs-mediatek: Do not gate clocks if auto-hibern8 is not entered yet Stanley Chu
@ 2020-05-22 12:18 ` Stanley Chu
2 siblings, 0 replies; 4+ messages in thread
From: Stanley Chu @ 2020-05-22 12:18 UTC (permalink / raw)
To: linux-scsi, martin.petersen, avri.altman, alim.akhtar, jejb
Cc: beanhuo, asutoshd, cang, matthias.bgg, bvanassche,
linux-mediatek, linux-arm-kernel, linux-kernel, kuohong.wang,
peter.wang, chun-hung.wu, andy.teng, cc.chou, chaotian.jing,
pengshun.zhao, Stanley Chu
Allow device power supply to enter low-power mode if device will
do nothing to save more power.
Signed-off-by: Stanley Chu <stanley.chu@mediatek.com>
Reviewed-by: Pengshun Zhao <pengshun.zhao@mediatek.com>
---
drivers/scsi/ufs/ufs-mediatek.c | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
diff --git a/drivers/scsi/ufs/ufs-mediatek.c b/drivers/scsi/ufs/ufs-mediatek.c
index 3c85f5e97dea..5f41b7b7db8f 100644
--- a/drivers/scsi/ufs/ufs-mediatek.c
+++ b/drivers/scsi/ufs/ufs-mediatek.c
@@ -12,6 +12,7 @@
#include <linux/of_address.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
#include <linux/soc/mediatek/mtk_sip_svc.h>
#include "ufshcd.h"
@@ -521,6 +522,19 @@ static int ufs_mtk_link_set_lpm(struct ufs_hba *hba)
return 0;
}
+static void ufs_mtk_vreg_set_lpm(struct ufs_hba *hba, bool lpm)
+{
+ if (!hba->vreg_info.vccq2)
+ return;
+
+ if (lpm & !hba->vreg_info.vcc->enabled)
+ regulator_set_mode(hba->vreg_info.vccq2->reg,
+ REGULATOR_MODE_IDLE);
+ else if (!lpm)
+ regulator_set_mode(hba->vreg_info.vccq2->reg,
+ REGULATOR_MODE_NORMAL);
+}
+
static int ufs_mtk_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
{
int err;
@@ -537,6 +551,12 @@ static int ufs_mtk_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
ufshcd_set_link_off(hba);
return -EAGAIN;
}
+ /*
+ * Make sure no error will be returned to prevent
+ * ufshcd_suspend() re-enabling regulators while vreg is still
+ * in low-power mode.
+ */
+ ufs_mtk_vreg_set_lpm(hba, true);
}
if (!ufshcd_is_link_active(hba))
@@ -554,6 +574,7 @@ static int ufs_mtk_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
phy_power_on(host->mphy);
if (ufshcd_is_link_hibern8(hba)) {
+ ufs_mtk_vreg_set_lpm(hba, false);
err = ufs_mtk_link_set_hpm(hba);
if (err) {
err = ufshcd_link_recovery(hba);
--
2.18.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
end of thread, other threads:[~2020-05-22 12:18 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2020-05-22 12:18 [PATCH v1 0/3] scsi: ufs-mediatek: Fix clk-gating and introduce low-power mode for vccq2 Stanley Chu
2020-05-22 12:18 ` [PATCH v1 1/3] scsi: ufs-mediatek: Fix imprecise waiting time for ref-clk control Stanley Chu
2020-05-22 12:18 ` [PATCH v1 2/3] scsi: ufs-mediatek: Do not gate clocks if auto-hibern8 is not entered yet Stanley Chu
2020-05-22 12:18 ` [PATCH v1 3/3] scsi: ufs-mediatek: Introduce low-power mode for device power supply Stanley Chu
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