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Date: Sun, 17 May 2020 01:46:15 +0800
From: Stanley Chu <stanley.chu@...iatek.com>
To: <linux-scsi@...r.kernel.org>, <martin.petersen@...cle.com>,
<avri.altman@....com>, <alim.akhtar@...sung.com>,
<jejb@...ux.ibm.com>, <asutoshd@...eaurora.org>
CC: <beanhuo@...ron.com>, <cang@...eaurora.org>,
<matthias.bgg@...il.com>, <bvanassche@....org>,
<linux-mediatek@...ts.infradead.org>,
<linux-arm-kernel@...ts.infradead.org>,
<linux-kernel@...r.kernel.org>, <kuohong.wang@...iatek.com>,
<peter.wang@...iatek.com>, <chun-hung.wu@...iatek.com>,
<andy.teng@...iatek.com>, Stanley Chu <stanley.chu@...iatek.com>
Subject: [PATCH v3 5/5] scsi: ufs: Fix possible VCC power drain during runtime suspend
The commit "scsi: ufs: Fix WriteBooster flush during runtime
suspend" promises essential resource, i.e., for UFS devices doing
WriteBooster buffer flush and Auto BKOPs. However if device
finishes its job but not resumed for a very long time, system
will have unnecessary power drain because VCC is still supplied.
To fix this, a method to recheck the threshold of keeping VCC
supply is required. However, the threshold recheck needs to
re-activate the link because the decision depends on the device
status.
Introduce a delayed work to force runtime resume after a certain
delay during runtime suspend. This makes threshold recheck simpler
which will be done in the next runtime-suspend.
Signed-off-by: Stanley Chu <stanley.chu@...iatek.com>
---
drivers/scsi/ufs/ufs.h | 1 +
drivers/scsi/ufs/ufshcd.c | 43 ++++++++++++++++++++++++++++++++++-----
drivers/scsi/ufs/ufshcd.h | 1 +
3 files changed, 40 insertions(+), 5 deletions(-)
diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h
index db07eedfed96..c70845d41449 100644
--- a/drivers/scsi/ufs/ufs.h
+++ b/drivers/scsi/ufs/ufs.h
@@ -574,6 +574,7 @@ struct ufs_dev_info {
u32 d_ext_ufs_feature_sup;
u8 b_wb_buffer_type;
u32 d_wb_alloc_units;
+ bool b_rpm_dev_flush_capable;
u8 b_presrv_uspc_en;
};
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index f4f2c7b5ab0a..a137553f9b41 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -94,6 +94,9 @@
/* default delay of autosuspend: 2000 ms */
#define RPM_AUTOSUSPEND_DELAY_MS 2000
+/* Default delay of RPM device flush delayed work */
+#define RPM_DEV_FLUSH_RECHECK_WORK_DELAY_MS 5000
+
/* Default value of wait time before gating device ref clock */
#define UFSHCD_REF_CLK_GATING_WAIT_US 0xFF /* microsecs */
@@ -5310,7 +5313,7 @@ static bool ufshcd_wb_presrv_usrspc_keep_vcc_on(struct ufs_hba *hba,
return false;
}
-static bool ufshcd_wb_keep_vcc_on(struct ufs_hba *hba)
+static bool ufshcd_wb_need_flush(struct ufs_hba *hba)
{
int ret;
u32 avail_buf;
@@ -5348,6 +5351,21 @@ static bool ufshcd_wb_keep_vcc_on(struct ufs_hba *hba)
return ufshcd_wb_presrv_usrspc_keep_vcc_on(hba, avail_buf);
}
+static void ufshcd_rpm_dev_flush_recheck_work(struct work_struct *work)
+{
+ struct ufs_hba *hba = container_of(to_delayed_work(work),
+ struct ufs_hba,
+ rpm_dev_flush_recheck_work);
+ /*
+ * To prevent unnecessary VCC power drain after device finishes
+ * WriteBooster buffer flush or Auto BKOPs, force runtime resume
+ * after a certain delay to recheck the threshold by next runtime
+ * supsend.
+ */
+ pm_runtime_get_sync(hba->dev);
+ pm_runtime_put_sync(hba->dev);
+}
+
/**
* ufshcd_exception_event_handler - handle exceptions raised by device
* @work: pointer to work data
@@ -8164,7 +8182,6 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
enum ufs_pm_level pm_lvl;
enum ufs_dev_pwr_mode req_dev_pwr_mode;
enum uic_link_state req_link_state;
- bool keep_curr_dev_pwr_mode = false;
hba->pm_op_in_progress = 1;
if (!ufshcd_is_shutdown_pm(pm_op)) {
@@ -8224,11 +8241,12 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
* Hibern8, keep device power mode as "active power mode"
* and VCC supply.
*/
- keep_curr_dev_pwr_mode = hba->auto_bkops_enabled ||
+ hba->dev_info.b_rpm_dev_flush_capable =
+ hba->auto_bkops_enabled ||
(((req_link_state == UIC_LINK_HIBERN8_STATE) ||
((req_link_state == UIC_LINK_ACTIVE_STATE) &&
ufshcd_is_auto_hibern8_enabled(hba))) &&
- ufshcd_wb_keep_vcc_on(hba));
+ ufshcd_wb_need_flush(hba));
}
if (req_dev_pwr_mode != hba->curr_dev_pwr_mode) {
@@ -8238,7 +8256,7 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
ufshcd_disable_auto_bkops(hba);
}
- if (!keep_curr_dev_pwr_mode) {
+ if (!hba->dev_info.b_rpm_dev_flush_capable) {
ret = ufshcd_set_dev_pwr_mode(hba, req_dev_pwr_mode);
if (ret)
goto enable_gating;
@@ -8295,9 +8313,16 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
if (hba->clk_scaling.is_allowed)
ufshcd_resume_clkscaling(hba);
hba->clk_gating.is_suspended = false;
+ hba->dev_info.b_rpm_dev_flush_capable = false;
ufshcd_release(hba);
out:
+ if (hba->dev_info.b_rpm_dev_flush_capable) {
+ schedule_delayed_work(&hba->rpm_dev_flush_recheck_work,
+ msecs_to_jiffies(RPM_DEV_FLUSH_RECHECK_WORK_DELAY_MS));
+ }
+
hba->pm_op_in_progress = 0;
+
if (ret)
ufshcd_update_reg_hist(&hba->ufs_stats.suspend_err, (u32)ret);
return ret;
@@ -8386,6 +8411,11 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
/* Enable Auto-Hibernate if configured */
ufshcd_auto_hibern8_enable(hba);
+ if (hba->dev_info.b_rpm_dev_flush_capable) {
+ hba->dev_info.b_rpm_dev_flush_capable = false;
+ cancel_delayed_work(&hba->rpm_dev_flush_recheck_work);
+ }
+
/* Schedule clock gating in case of no access to UFS device yet */
ufshcd_release(hba);
@@ -8859,6 +8889,9 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq)
UFS_SLEEP_PWR_MODE,
UIC_LINK_HIBERN8_STATE);
+ INIT_DELAYED_WORK(&hba->rpm_dev_flush_recheck_work,
+ ufshcd_rpm_dev_flush_recheck_work);
+
/* Set the default auto-hiberate idle timer value to 150 ms */
if (ufshcd_is_auto_hibern8_supported(hba) && !hba->ahit) {
hba->ahit = FIELD_PREP(UFSHCI_AHIBERN8_TIMER_MASK, 150) |
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 8db7a6101892..9acd437037e8 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -745,6 +745,7 @@ struct ufs_hba {
struct request_queue *bsg_queue;
bool wb_buf_flush_enabled;
bool wb_enabled;
+ struct delayed_work rpm_dev_flush_recheck_work;
};
/* Returns true if clocks can be gated. Otherwise false */
--
2.18.0
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