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UFS driver general fixes bundle 4

PATCH Superseded Can Guo 3 participants 11 messages Jan 23, 2020

Subsystems (2)

v3 of 10 Superseded Latest is v10 →

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Can Guo

author
#0 lore raw

v3 cover UFS driver general fixes bundle 4

This bundle includes 8 general fixes for UFS driver.

Changes since v2:
- Move the ref clk gating wait delay to ufs-qcom.c
- Added one more change to select INITIAL adapt for HS G4

Changes since v1:
- Fixed minor typo

Asutosh Das (1):
scsi: ufs: set load before setting voltage in regulators

Can Guo (6):
scsi: ufs: Remove the check before call setup clock notify vops
scsi: ufs-qcom: Adjust bus bandwidth voting and unvoting
scsi: ufs: Fix ufshcd_hold() caused scheduling while atomic
scsi: ufs: Add dev ref clock gating wait time support
scsi: ufs-qcom: Delay specific time before gate ref clk
scsi: ufs: Select INITIAL adapt for HS Gear4

Sayali Lokhande (1):
scsi: ufs: Flush exception event before suspend

 drivers/scsi/ufs/ufs-qcom.c |  70 +++++++++++++++++++---------
 drivers/scsi/ufs/ufs.h      |   3 ++
 drivers/scsi/ufs/ufshcd.c   | 111 +++++++++++++++++++++++++++++++++-----------
 drivers/scsi/ufs/unipro.h   |   1 +
 4 files changed, 136 insertions(+), 49 deletions(-)
Signature · 2 lines
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
author
#1 lore raw

PATCH v3 1/8 scsi: ufs: Flush exception event before suspend

From: Sayali Lokhande <[email protected]>

Exception event can be raised by the device when system suspend is in progress. This will result in unclocked register access in exception event handler as clocks will be turned off during suspend. This change makes sure to flush exception event handler work in suspend before disabling clocks to avoid unclocked register access issue.

---
 drivers/scsi/ufs/ufshcd.c | 21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)
drivers/scsi/ufs/ufshcd.c +18 -3
index 1201578..c2de29f 100644
@@ -4760,8 +4760,15 @@ static void ufshcd_slave_destroy(struct scsi_device *sdev)
 			 * UFS device needs urgent BKOPs.
 			 */
 			if (!hba->pm_op_in_progress &&
-			    ufshcd_is_exception_event(lrbp->ucd_rsp_ptr))
-				schedule_work(&hba->eeh_work);
+			    ufshcd_is_exception_event(lrbp->ucd_rsp_ptr)) {
+				/*
+				 * Prevent suspend once eeh_work is scheduled
+				 * to avoid deadlock between ufshcd_suspend
+				 * and exception event handler.
+				 */
+				if (schedule_work(&hba->eeh_work))
+					pm_runtime_get_noresume(hba->dev);
+			}
 			break;
 		case UPIU_TRANSACTION_REJECT_UPIU:
 			/* TODO: handle Reject UPIU Response */
@@ -5215,7 +5222,14 @@ static void ufshcd_exception_event_handler(struct work_struct *work)
 
 out:
 	scsi_unblock_requests(hba->host);
-	pm_runtime_put_sync(hba->dev);
+	/*
+	 * pm_runtime_get_noresume is called while scheduling
+	 * eeh_work to avoid suspend racing with exception work.
+	 * Hence decrement usage counter using pm_runtime_put_noidle
+	 * to allow suspend on completion of exception event handler.
+	 */
+	pm_runtime_put_noidle(hba->dev);
+	pm_runtime_put(hba->dev);
 	return;
 }
 
@@ -7901,6 +7915,7 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 			goto enable_gating;
 	}
 
+	flush_work(&hba->eeh_work);
 	ret = ufshcd_link_state_transition(hba, req_link_state, 1);
 	if (ret)
 		goto set_dev_active;
Signature · 2 lines
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a Linux Foundation Collaborative Project
#2 lore raw

RE: [EXT] [PATCH v3 1/8] scsi: ufs: Flush exception event before suspend

Hi, Can

Quoted 24 lines
drivers/scsi/ufs/ufshcd.c +10 -2
 			 * UFS device needs urgent BKOPs.
 			 */
 			if (!hba->pm_op_in_progress &&
-			    ufshcd_is_exception_event(lrbp->ucd_rsp_ptr))
-				schedule_work(&hba->eeh_work);
+			    ufshcd_is_exception_event(lrbp->ucd_rsp_ptr)) {
+				/*
+				 * Prevent suspend once eeh_work is scheduled
+				 * to avoid deadlock between ufshcd_suspend
+				 * and exception event handler.
+				 */
+				if (schedule_work(&hba->eeh_work))
+					pm_runtime_get_noresume(hba->dev);
+			}
 			break;
 		case UPIU_TRANSACTION_REJECT_UPIU:
 			/* TODO: handle Reject UPIU Response */ @@ -5215,7
+5222,14 @@ static void ufshcd_exception_event_handler(struct work_struct

*work)

out:

drivers/scsi/ufs/ufshcd.c +0 -1
 	scsi_unblock_requests(hba->host);
-	pm_runtime_put_sync(hba->dev);

drivers/scsi/ufs/ufshcd.c static void ufshcd_exception_event_handler(struct work_struct *work) · line 5234

Quoted 10 lines
drivers/scsi/ufs/ufshcd.c +8 -0
+	/*
+	 * pm_runtime_get_noresume is called while scheduling
+	 * eeh_work to avoid suspend racing with exception work.
+	 * Hence decrement usage counter using pm_runtime_put_noidle
+	 * to allow suspend on completion of exception event handler.
+	 */
+	pm_runtime_put_noidle(hba->dev);
+	pm_runtime_put(hba->dev);
 	return;
 }

You should rebase your this series patch, I installed your patches, it failed, there are several conflicts.

Thanks,

//Bean

author
#3 lore raw

PATCH v3 2/8 scsi: ufs: set load before setting voltage in regulators

In reply to Can Guo

From: Asutosh Das <[email protected]>

This sequence change is required to avoid dips in voltage during boot-up.

Apparently, this dip is caused because in the original sequence, the regulators are initialized in lpm mode. And then when the load is set to high, and more current is drawn, than is allowed in lpm, the dip is seen.

---
 drivers/scsi/ufs/ufshcd.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)
drivers/scsi/ufs/ufshcd.c +5 -5
index c2de29f..c386c2d 100644
@@ -7225,6 +7225,11 @@ static int ufshcd_config_vreg(struct device *dev,
 	name = vreg->name;
 
 	if (regulator_count_voltages(reg) > 0) {
+		uA_load = on ? vreg->max_uA : 0;
+		ret = ufshcd_config_vreg_load(dev, vreg, uA_load);
+		if (ret)
+			goto out;
+
 		if (vreg->min_uV && vreg->max_uV) {
 			min_uV = on ? vreg->min_uV : 0;
 			ret = regulator_set_voltage(reg, min_uV, vreg->max_uV);
@@ -7235,11 +7240,6 @@ static int ufshcd_config_vreg(struct device *dev,
 				goto out;
 			}
 		}
-
-		uA_load = on ? vreg->max_uA : 0;
-		ret = ufshcd_config_vreg_load(dev, vreg, uA_load);
-		if (ret)
-			goto out;
 	}
 out:
 	return ret;
Signature · 2 lines
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
author
#4 lore raw

PATCH v3 3/8 scsi: ufs: Remove the check before call setup clock notify vops

In reply to Can Guo

The functionality of vendor specific ops should be handled properly in platform specific driver, but should not count on the UFS driver.

---
 drivers/scsi/ufs/ufshcd.c | 26 ++++++--------------------
 1 file changed, 6 insertions(+), 20 deletions(-)
drivers/scsi/ufs/ufshcd.c +6 -20
index c386c2d..4dfd705 100644
@@ -7379,16 +7379,9 @@ static int __ufshcd_setup_clocks(struct ufs_hba *hba, bool on,
 	if (list_empty(head))
 		goto out;
 
-	/*
-	 * vendor specific setup_clocks ops may depend on clocks managed by
-	 * this standard driver hence call the vendor specific setup_clocks
-	 * before disabling the clocks managed here.
-	 */
-	if (!on) {
-		ret = ufshcd_vops_setup_clocks(hba, on, PRE_CHANGE);
-		if (ret)
-			return ret;
-	}
+	ret = ufshcd_vops_setup_clocks(hba, on, PRE_CHANGE);
+	if (ret)
+		return ret;
 
 	list_for_each_entry(clki, head, list) {
 		if (!IS_ERR_OR_NULL(clki->clk)) {
@@ -7412,16 +7405,9 @@ static int __ufshcd_setup_clocks(struct ufs_hba *hba, bool on,
 		}
 	}
 
-	/*
-	 * vendor specific setup_clocks ops may depend on clocks managed by
-	 * this standard driver hence call the vendor specific setup_clocks
-	 * after enabling the clocks managed here.
-	 */
-	if (on) {
-		ret = ufshcd_vops_setup_clocks(hba, on, POST_CHANGE);
-		if (ret)
-			return ret;
-	}
+	ret = ufshcd_vops_setup_clocks(hba, on, POST_CHANGE);
+	if (ret)
+		return ret;
 
 out:
 	if (ret) {
Signature · 2 lines
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
author
#5 lore raw

PATCH v3 4/8 scsi: ufs-qcom: Adjust bus bandwidth voting and unvoting

In reply to Can Guo

The bus bandwidth voting is required to be done before the bus clocks are enabled, and the unvoting is required to be done only after the bus clocks are disabled.

---
 drivers/scsi/ufs/ufs-qcom.c | 57 +++++++++++++++++++++++++++++++--------------
 1 file changed, 39 insertions(+), 18 deletions(-)
drivers/scsi/ufs/ufs-qcom.c +39 -18
index c69c29a1c..85d7c17 100644
@@ -38,7 +38,6 @@ enum {
 
 static struct ufs_qcom_host *ufs_qcom_hosts[MAX_UFS_QCOM_HOSTS];
 
-static int ufs_qcom_set_bus_vote(struct ufs_qcom_host *host, int vote);
 static void ufs_qcom_get_default_testbus_cfg(struct ufs_qcom_host *host);
 static int ufs_qcom_set_dme_vs_core_clk_ctrl_clear_div(struct ufs_hba *hba,
 						       u32 clk_cycles);
@@ -674,7 +673,7 @@ static void ufs_qcom_get_speed_mode(struct ufs_pa_layer_attr *p, char *result)
 	}
 }
 
-static int ufs_qcom_set_bus_vote(struct ufs_qcom_host *host, int vote)
+static int __ufs_qcom_set_bus_vote(struct ufs_qcom_host *host, int vote)
 {
 	int err = 0;
 
@@ -705,7 +704,7 @@ static int ufs_qcom_update_bus_bw_vote(struct ufs_qcom_host *host)
 
 	vote = ufs_qcom_get_bus_vote(host, mode);
 	if (vote >= 0)
-		err = ufs_qcom_set_bus_vote(host, vote);
+		err = __ufs_qcom_set_bus_vote(host, vote);
 	else
 		err = vote;
 
@@ -716,6 +715,35 @@ static int ufs_qcom_update_bus_bw_vote(struct ufs_qcom_host *host)
 	return err;
 }
 
+static int ufs_qcom_set_bus_vote(struct ufs_hba *hba, bool on)
+{
+	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
+	int vote, err;
+
+	/*
+	 * In case ufs_qcom_init() is not yet done, simply ignore.
+	 * This ufs_qcom_set_bus_vote() shall be called from
+	 * ufs_qcom_init() after init is done.
+	 */
+	if (!host)
+		return 0;
+
+	if (on) {
+		vote = host->bus_vote.saved_vote;
+		if (vote == host->bus_vote.min_bw_vote)
+			ufs_qcom_update_bus_bw_vote(host);
+	} else {
+		vote = host->bus_vote.min_bw_vote;
+	}
+
+	err = __ufs_qcom_set_bus_vote(host, vote);
+	if (err)
+		dev_err(hba->dev, "%s: set bus vote failed %d\n",
+				 __func__, err);
+
+	return err;
+}
+
 static ssize_t
 show_ufs_to_mem_max_bus_bw(struct device *dev, struct device_attribute *attr,
 			char *buf)
@@ -792,7 +820,7 @@ static int ufs_qcom_update_bus_bw_vote(struct ufs_qcom_host *host)
 	return 0;
 }
 
-static int ufs_qcom_set_bus_vote(struct ufs_qcom_host *host, int vote)
+static int ufs_qcom_set_bus_vote(struct ufs_hba *host, bool on)
 {
 	return 0;
 }
@@ -1030,8 +1058,7 @@ static int ufs_qcom_setup_clocks(struct ufs_hba *hba, bool on,
 				 enum ufs_notify_change_status status)
 {
 	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
-	int err;
-	int vote = 0;
+	int err = 0;
 
 	/*
 	 * In case ufs_qcom_init() is not yet done, simply ignore.
@@ -1041,28 +1068,21 @@ static int ufs_qcom_setup_clocks(struct ufs_hba *hba, bool on,
 	if (!host)
 		return 0;
 
-	if (on && (status == POST_CHANGE)) {
+	if (on && (status == PRE_CHANGE)) {
+		err = ufs_qcom_set_bus_vote(hba, true);
+	} else if (on && (status == POST_CHANGE)) {
 		/* enable the device ref clock for HS mode*/
 		if (ufshcd_is_hs_mode(&hba->pwr_info))
 			ufs_qcom_dev_ref_clk_ctrl(host, true);
-		vote = host->bus_vote.saved_vote;
-		if (vote == host->bus_vote.min_bw_vote)
-			ufs_qcom_update_bus_bw_vote(host);
-
 	} else if (!on && (status == PRE_CHANGE)) {
 		if (!ufs_qcom_is_link_active(hba)) {
 			/* disable device ref_clk */
 			ufs_qcom_dev_ref_clk_ctrl(host, false);
 		}
-
-		vote = host->bus_vote.min_bw_vote;
+	} else if (!on && (status == POST_CHANGE)) {
+		err = ufs_qcom_set_bus_vote(hba, false);
 	}
 
-	err = ufs_qcom_set_bus_vote(host, vote);
-	if (err)
-		dev_err(hba->dev, "%s: set bus vote failed %d\n",
-				__func__, err);
-
 	return err;
 }
 
@@ -1238,6 +1258,7 @@ static int ufs_qcom_init(struct ufs_hba *hba)
 	ufs_qcom_set_caps(hba);
 	ufs_qcom_advertise_quirks(hba);
 
+	ufs_qcom_set_bus_vote(hba, true);
 	ufs_qcom_setup_clocks(hba, true, POST_CHANGE);
 
 	if (hba->dev->id < MAX_UFS_QCOM_HOSTS)
Signature · 2 lines
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a Linux Foundation Collaborative Project
author
#6 lore raw

PATCH v3 5/8 scsi: ufs: Fix ufshcd_hold() caused scheduling while atomic

In reply to Can Guo

The async version of ufshcd_hold(async == true), which is only called in queuecommand path as for now, is expected to work in atomic context, thus it should not sleep or schedule out. When it runs into the condition that clocks are ON but link is still in hibern8 state, it should bail out without flushing the clock ungate work.

---
 drivers/scsi/ufs/ufshcd.c | 5 +++++
 1 file changed, 5 insertions(+)
drivers/scsi/ufs/ufshcd.c +5 -0
index 4dfd705..c316a07 100644
@@ -1542,6 +1542,11 @@ int ufshcd_hold(struct ufs_hba *hba, bool async)
 		 */
 		if (ufshcd_can_hibern8_during_gating(hba) &&
 		    ufshcd_is_link_hibern8(hba)) {
+			if (async) {
+				rc = -EAGAIN;
+				hba->clk_gating.active_reqs--;
+				break;
+			}
 			spin_unlock_irqrestore(hba->host->host_lock, flags);
 			flush_work(&hba->clk_gating.ungate_work);
 			spin_lock_irqsave(hba->host->host_lock, flags);
Signature · 2 lines
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a Linux Foundation Collaborative Project
Reviewed-by on v3 5/8
#7 lore raw

Re: [PATCH v3 5/8] scsi: ufs: Fix ufshcd_hold() caused scheduling while atomic

Hi Can,

Quoted 17 lines · Can Guo

The async version of ufshcd_hold(async == true), which is only called in queuecommand path as for now, is expected to work in atomic context, thus it should not sleep or schedule out. When it runs into the condition that clocks are ON but link is still in hibern8 state, it should bail out without flushing the clock ungate work.

---
 drivers/scsi/ufs/ufshcd.c | 5 +++++
 1 file changed, 5 insertions(+)
drivers/scsi/ufs/ufshcd.c +0 -0
index 4dfd705..c316a07 100644
@@ -1542,6 +1542,11 @@ int ufshcd_hold(struct ufs_hba *hba, bool async)
 		 */

drivers/scsi/ufs/ufshcd.c int ufshcd_hold(struct ufs_hba *hba, bool async) · line 1552

Quoted 10 lines
drivers/scsi/ufs/ufshcd.c +5 -0
 		if (ufshcd_can_hibern8_during_gating(hba) &&
 		    ufshcd_is_link_hibern8(hba)) {
+			if (async) {
+				rc = -EAGAIN;
+				hba->clk_gating.active_reqs--;
+				break;
+			}
 			spin_unlock_irqrestore(hba->host->host_lock, flags);
 			flush_work(&hba->clk_gating.ungate_work);
 			spin_lock_irqsave(hba->host->host_lock, flags);

It looks good to me.

author
#8 lore raw

PATCH v3 6/8 scsi: ufs: Add dev ref clock gating wait time support

In reply to Can Guo

In UFS version 3.0, a newly added attribute bRefClkGatingWaitTime defines the minimum time for which the reference clock is required by device during transition to LS-MODE or HIBERN8 state. Make this change to reflect the new requirement by adding delays before turning off the clock.

---
 drivers/scsi/ufs/ufs.h    |  3 +++
 drivers/scsi/ufs/ufshcd.c | 41 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 44 insertions(+)
drivers/scsi/ufs/ufs.h +3 -0
index 3327981..385bac8 100644
@@ -168,6 +168,7 @@ enum attr_idn {
 	QUERY_ATTR_IDN_FFU_STATUS		= 0x14,
 	QUERY_ATTR_IDN_PSA_STATE		= 0x15,
 	QUERY_ATTR_IDN_PSA_DATA_SIZE		= 0x16,
+	QUERY_ATTR_IDN_REF_CLK_GATING_WAIT_TIME	= 0x17,
 };
 
 /* Descriptor idn for Query requests */
@@ -530,6 +531,8 @@ struct ufs_dev_info {
 	bool f_power_on_wp_en;
 	/* Keeps information if any of the LU is power on write protected */
 	bool is_lu_power_on_wp;
+	u16 spec_version;
+	u32 clk_gating_wait_us;
 };
 
 #define MAX_MODEL_LEN 16
drivers/scsi/ufs/ufshcd.c +41 -0

65 lines not on this page · raw message

Signature · 2 lines
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
author
#9 lore raw

PATCH v3 7/8 scsi: ufs-qcom: Delay specific time before gate ref clk

In reply to Can Guo

After enter hibern8, as UFS JEDEC ver 3.0 requires, a specific gating wait time is required before disable the device reference clock. If it is not specified, use the old delay.

---
 drivers/scsi/ufs/ufs-qcom.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)
drivers/scsi/ufs/ufs-qcom.c +10 -3
index 85d7c17..3b5b2d9 100644
@@ -833,6 +833,8 @@ static int ufs_qcom_bus_register(struct ufs_qcom_host *host)
 
 static void ufs_qcom_dev_ref_clk_ctrl(struct ufs_qcom_host *host, bool enable)
 {
+	unsigned long gating_wait;
+
 	if (host->dev_ref_clk_ctrl_mmio &&
 	    (enable ^ host->is_dev_ref_clk_enabled)) {
 		u32 temp = readl_relaxed(host->dev_ref_clk_ctrl_mmio);
@@ -845,11 +847,16 @@ static void ufs_qcom_dev_ref_clk_ctrl(struct ufs_qcom_host *host, bool enable)
 		/*
 		 * If we are here to disable this clock it might be immediately
 		 * after entering into hibern8 in which case we need to make
-		 * sure that device ref_clk is active at least 1us after the
+		 * sure that device ref_clk is active for specific time after
 		 * hibern8 enter.
 		 */
-		if (!enable)
-			udelay(1);
+		if (!enable) {
+			gating_wait = host->hba->dev_info.clk_gating_wait_us;
+			if (!gating_wait)
+				udelay(1);
+			else
+				usleep_range(gating_wait, gating_wait + 10);
+		}
 
 		writel_relaxed(temp, host->dev_ref_clk_ctrl_mmio);
 
Signature · 2 lines
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
author
#10 lore raw

PATCH v3 8/8 scsi: ufs: Select INITIAL adapt for HS Gear4

In reply to Can Guo

ADAPT is added specifically for HS Gear4 mode only, select INITIAL adapt before do power mode change to G4 and select no adapt before switch to non-G4 modes.

---
 drivers/scsi/ufs/ufshcd.c | 8 ++++++++
 drivers/scsi/ufs/unipro.h | 1 +
 2 files changed, 9 insertions(+)
drivers/scsi/ufs/ufshcd.c +8 -0
index 1ee2187..20b9428 100644
@@ -4134,6 +4134,14 @@ static int ufshcd_change_power_mode(struct ufs_hba *hba,
 		ufshcd_dme_set(hba, UIC_ARG_MIB(PA_HSSERIES),
 						pwr_mode->hs_rate);
 
+	if (pwr_mode->gear_tx == UFS_HS_G4)
+		/* INITIAL ADAPT */
+		ufshcd_dme_set(hba, UIC_ARG_MIB(PA_TXHSADAPTTYPE),
+						PA_INITIAL_ADAPT);
+	else
+		/* NO ADAPT */
+		ufshcd_dme_set(hba, UIC_ARG_MIB(PA_TXHSADAPTTYPE), PA_NO_ADAPT);
+
 	ret = ufshcd_uic_change_pwr_mode(hba, pwr_mode->pwr_rx << 4
 			| pwr_mode->pwr_tx);
 
drivers/scsi/ufs/unipro.h +1 -0
index f539f87..bd1c3d6 100644
@@ -192,6 +192,7 @@ enum ufs_hs_gear_tag {
 	UFS_HS_G1,		/* HS Gear 1 (default for reset) */
 	UFS_HS_G2,		/* HS Gear 2 */
 	UFS_HS_G3,		/* HS Gear 3 */
+	UFS_HS_G4,		/* HS Gear 4 */
 };
 
 enum ufs_unipro_ver {
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