Re: [PATCH v1 1/1] scsi: ufs: Fix ufs power down/on specs violation
From: Can Guo
Date: Wed Dec 09 2020 - 02:28:49 EST
On 2020-12-09 15:09, Ziqi Chen wrote:
As per specs, e.g, JESD220E chapter 7.2, while powering
off/on the ufs device, RST_N signal and REF_CLK signal
should be between VSS(Ground) and VCCQ/VCCQ2.
Power down:
1. Assert RST_N low
2. Turn-off REF_CLK
3. Turn-off VCC
4. Turn-off VCCQ/VCCQ2.
power on:
1. Turn-on VCC
2. Turn-on VCCQ/VCCQ2
3. Turn-On REF_CLK
4. Deassert RST_N high.
Signed-off-by: Ziqi Chen <ziqichen@xxxxxxxxxxxxxx>
---
drivers/scsi/ufs/ufs-qcom.c | 14 ++++++++++----
drivers/scsi/ufs/ufshcd.c | 19 +++++++++----------
drivers/scsi/ufs/ufshcd.h | 4 ++--
3 files changed, 21 insertions(+), 16 deletions(-)
diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
index 1e434cc..5ed3a63d 100644
--- a/drivers/scsi/ufs/ufs-qcom.c
+++ b/drivers/scsi/ufs/ufs-qcom.c
@@ -582,6 +582,9 @@ static int ufs_qcom_suspend(struct ufs_hba *hba,
enum ufs_pm_op pm_op)
ufs_qcom_disable_lane_clks(host);
phy_power_off(phy);
+ if (hba->vops && hba->vops->device_reset)
+ hba->vops->device_reset(hba, false);
+
Instead of doing the pull-down in ufshcd_vops_suspend(), can we do
it in ufshcd_suspend()? Since it is a common problem for all soc
vendors.
} else if (!ufs_qcom_is_link_active(hba)) {
ufs_qcom_disable_lane_clks(host);
}
@@ -1400,10 +1403,11 @@ static void ufs_qcom_dump_dbg_regs(struct
ufs_hba *hba)
/**
* ufs_qcom_device_reset() - toggle the (optional) device reset line
* @hba: per-adapter instance
+ * @toggle: need pulling up or not
*
* Toggles the (optional) reset line to reset the attached device.
*/
-static int ufs_qcom_device_reset(struct ufs_hba *hba)
+static int ufs_qcom_device_reset(struct ufs_hba *hba, bool toggle)
{
struct ufs_qcom_host *host = ufshcd_get_variant(hba);
@@ -1416,10 +1420,12 @@ static int ufs_qcom_device_reset(struct ufs_hba
*hba)
* be on the safe side.
*/
gpiod_set_value_cansleep(host->device_reset, 1);
- usleep_range(10, 15);
- gpiod_set_value_cansleep(host->device_reset, 0);
- usleep_range(10, 15);
+ if (toggle) {
+ usleep_range(10, 15);
+ gpiod_set_value_cansleep(host->device_reset, 0);
+ usleep_range(10, 15);
+ }
return 0;
}
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 92d433d..5ab1c02 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -8633,8 +8633,6 @@ static int ufshcd_suspend(struct ufs_hba *hba,
enum ufs_pm_op pm_op)
if (ret)
goto set_dev_active;
- ufshcd_vreg_set_lpm(hba);
-
disable_clks:
/*
* Call vendor specific suspend callback. As these callbacks may
access
@@ -8664,6 +8662,7 @@ static int ufshcd_suspend(struct ufs_hba *hba,
enum ufs_pm_op pm_op)
/* Put the host controller in low power mode if possible */
ufshcd_hba_vreg_set_lpm(hba);
+ ufshcd_vreg_set_lpm(hba);
Can you put ufshcd_vreg_set_lpm() before ufshcd_hba_vreg_set_lpm()?
goto out;
set_link_active:
@@ -8729,18 +8728,18 @@ static int ufshcd_resume(struct ufs_hba *hba,
enum ufs_pm_op pm_op)
old_link_state = hba->uic_link_state;
ufshcd_hba_vreg_set_hpm(hba);
+ ret = ufshcd_vreg_set_hpm(hba);
+ if (ret)
+ goto out;
+
/* Make sure clocks are enabled before accessing controller */
ret = ufshcd_setup_clocks(hba, true);
if (ret)
- goto out;
+ goto disable_vreg;
/* enable the host irq as host controller would be active soon */
ufshcd_enable_irq(hba);
- ret = ufshcd_vreg_set_hpm(hba);
- if (ret)
- goto disable_irq_and_vops_clks;
-
/*
* Call vendor specific resume callback. As these callbacks may
access
* vendor specific host controller register space call them when the
@@ -8748,7 +8747,7 @@ static int ufshcd_resume(struct ufs_hba *hba,
enum ufs_pm_op pm_op)
*/
ret = ufshcd_vops_resume(hba, pm_op);
if (ret)
- goto disable_vreg;
+ goto disable_irq_and_vops_clks;
/* For DeepSleep, the only supported option is to have the link off
*/
WARN_ON(ufshcd_is_ufs_dev_deepsleep(hba) &&
!ufshcd_is_link_off(hba));
@@ -8815,8 +8814,6 @@ static int ufshcd_resume(struct ufs_hba *hba,
enum ufs_pm_op pm_op)
ufshcd_link_state_transition(hba, old_link_state, 0);
vendor_suspend:
ufshcd_vops_suspend(hba, pm_op);
-disable_vreg:
- ufshcd_vreg_set_lpm(hba);
disable_irq_and_vops_clks:
ufshcd_disable_irq(hba);
if (hba->clk_scaling.is_allowed)
@@ -8827,6 +8824,8 @@ static int ufshcd_resume(struct ufs_hba *hba,
enum ufs_pm_op pm_op)
trace_ufshcd_clk_gating(dev_name(hba->dev),
hba->clk_gating.state);
}
+disable_vreg:
+ ufshcd_vreg_set_lpm(hba);
out:
hba->pm_op_in_progress = 0;
if (ret)
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 61344c4..47c7dab6 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -323,7 +323,7 @@ struct ufs_hba_variant_ops {
int (*resume)(struct ufs_hba *, enum ufs_pm_op);
void (*dbg_register_dump)(struct ufs_hba *hba);
int (*phy_initialization)(struct ufs_hba *);
- int (*device_reset)(struct ufs_hba *hba);
+ int (*device_reset)(struct ufs_hba *hba, bool);
void (*config_scaling_param)(struct ufs_hba *hba,
struct devfreq_dev_profile *profile,
void *data);
@@ -1211,7 +1211,7 @@ static inline void
ufshcd_vops_dbg_register_dump(struct ufs_hba *hba)
static inline void ufshcd_vops_device_reset(struct ufs_hba *hba)
{
if (hba->vops && hba->vops->device_reset) {
- int err = hba->vops->device_reset(hba);
+ int err = hba->vops->device_reset(hba, true);
if (!err)
ufshcd_set_ufs_dev_active(hba);