[PATCH v2 0/2] scsi: ufs: Add persistent TX Equalization settings support

[PATCH v2 0/2] scsi: ufs: Add persistent TX Equalization settings support

[Can Guo]

Hi,

This series is a follow-up to the earlier TX Equalization enablement series:

https://lore.kernel.org/all/20260325152154.1604082-1-can.guo@oss.qualcomm.com

In that cover letter, the "Next" section mentioned adding support for
UFS v5.0 Attributes qTxEQGnSettings and wTxEQGnSettingsExt, and enabling
persistent storage/retrieval of optimal TX Equalization settings. This
2-patch series implements that part.

Motivation
==========

TX EQTR procedure is required to find the optimal TX Equalization settings
for HS Gears (4-6) before changing Power Mode to the target HS Gears.
However, TX EQTR procedure introduces latencies to the first Power Mode
change.

With optimal TX Equalization settings stored in UFS v5.0 Attributes
qTxEQGnSettings and wTxEQGnSettingsExt, host software can reuse known-good
settings and avoid going through the TX EQTR procedure.

Array Attribute Model
=====================

qTxEQGnSettings and wTxEQGnSettingsExt are array-type Attributes. Each
element in an array-type Attribute is selected by an (Index, Selector) pair.

For these two attributes:
- Valid Index range: [0, Max HS Gear - 1]
- Valid Selector range: [0, 1]

This effectively forms a 2-dimensional array. For HS-Gear n, its TX
Equalization settings are stored/retrieved at Index (n - 1). Selector is
configurable via a module parameter so that platforms can choose the
Selector policy that matches their use.

Implementation Overview
=======================

1. Introduce a generic helper for 64-bit query attributes:
   ufshcd_query_attr_qword().

2. Add TX EQ settings persistence flow:
   - Read stored settings from qTxEQGnSettings & wTxEQGnSettingsExt.
   - Decode and populate per-gear TX EQ parameters.
   - Use Bit[15] in wTxEQGnSettingsExt as validity indication.
   - Store trained settings back to these attributes for future reuse.

3. Integrate with existing lifecycle:
   - Retrieve settings during device parameter initialization.
   - Store settings during shutdown.

New Module Parameters
=====================

Three module parameters are added for TX EQ settings persistence control:
- txeq_setting_sel (default: 0, range: 0..1)
    Selects which selector value is used when reading/writing
    qTxEQGnSettings and wTxEQGnSettingsExt.
- retrieve_txeq_setting (default: true)
    Enables/disables retrieving stored TX EQ settings from device attributes
    during initialization.
- store_txeq_setting (default: true)
    Enables/disables storing last trained TX EQ settings into device attributes
    during shutdown.

Testing
=======

Tested on a UFS v5.0 platform:
- TX Equalization setting store path, settings were correctly encoded and stored.
- TX Equalization setting retrieval path, settings were correctly extracted and reused.
- Full TX EQTR procedure was skipped for a given HS Gear when valid TX EQ settings
  were provided in qTxEQGnSettings & wTxEQGnSettingsExt for the given HS-Gear.

v1 -> v2:
1. Incorporated comments from Peter, Bart and Bean.
2. Fixed typos and minor coding style issues.
3. Converted macros to inline functions.


Can Guo (2):
  scsi: ufs: core: Introduce function ufshcd_query_attr_qword()
  scsi: ufs: core: Add support to retrieve and store TX Equalization
    settings

 drivers/ufs/core/ufs-sysfs.c   |  30 +++-
 drivers/ufs/core/ufs-txeq.c    | 287 +++++++++++++++++++++++++++++++++
 drivers/ufs/core/ufshcd-priv.h |   5 +-
 drivers/ufs/core/ufshcd.c      | 131 ++++++++-------
 include/ufs/ufs.h              |   2 +
 include/ufs/ufshcd.h           |   2 +
 6 files changed, 392 insertions(+), 65 deletions(-)

-- 
2.34.1

[PATCH v2 1/2] scsi: ufs: core: Introduce function ufshcd_query_attr_qword()

[Can Guo]

Introduce a new generic function ufshcd_query_attr_qword() to handle
quad-word (64-bit) UFS attribute operations. This consolidates the
handling of 64-bit attributes which was previously scattered across
multiple specialized functions.

Reviewed-by: Peter Wang <peter.wang@mediatek.com>
Signed-off-by: Can Guo <can.guo@oss.qualcomm.com>
---
 drivers/ufs/core/ufs-sysfs.c   |  30 ++++++--
 drivers/ufs/core/ufshcd-priv.h |   3 +-
 drivers/ufs/core/ufshcd.c      | 126 +++++++++++++++++----------------
 3 files changed, 94 insertions(+), 65 deletions(-)

diff --git a/drivers/ufs/core/ufs-sysfs.c b/drivers/ufs/core/ufs-sysfs.c
index 99af3c73f1af..d9dc4cc3452e 100644
--- a/drivers/ufs/core/ufs-sysfs.c
+++ b/drivers/ufs/core/ufs-sysfs.c
@@ -594,8 +594,13 @@ static ssize_t device_lvl_exception_id_show(struct device *dev,
 	u64 exception_id;
 	int err;
 
+	if (hba->dev_info.wspecversion < 0x410)
+		return -EOPNOTSUPP;
+
 	ufshcd_rpm_get_sync(hba);
-	err = ufshcd_read_device_lvl_exception_id(hba, &exception_id);
+	err = ufshcd_query_attr_qword(hba, UPIU_QUERY_OPCODE_READ_ATTR,
+				      QUERY_ATTR_IDN_DEV_LVL_EXCEPTION_ID,
+				      0, 0, &exception_id);
 	ufshcd_rpm_put_sync(hba);
 
 	if (err)
@@ -1670,6 +1675,12 @@ static inline bool ufshcd_is_wb_attrs(enum attr_idn idn)
 		idn <= QUERY_ATTR_IDN_CURR_WB_BUFF_SIZE;
 }
 
+static inline bool ufshcd_is_qword_attr(enum attr_idn idn)
+{
+	return idn == QUERY_ATTR_IDN_TIMESTAMP ||
+	       idn == QUERY_ATTR_IDN_DEV_LVL_EXCEPTION_ID;
+}
+
 static int wb_read_resize_attrs(struct ufs_hba *hba,
 			enum attr_idn idn, u32 *attr_val)
 {
@@ -1736,6 +1747,7 @@ static ssize_t _name##_show(struct device *dev,				\
 	struct device_attribute *attr, char *buf)			\
 {									\
 	struct ufs_hba *hba = dev_get_drvdata(dev);			\
+	u64 qword_value;						\
 	u32 value;							\
 	int ret;							\
 	u8 index = 0;							\
@@ -1748,14 +1760,24 @@ static ssize_t _name##_show(struct device *dev,				\
 	if (ufshcd_is_wb_attrs(QUERY_ATTR_IDN##_uname))			\
 		index = ufshcd_wb_get_query_index(hba);			\
 	ufshcd_rpm_get_sync(hba);					\
-	ret = ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_READ_ATTR,	\
-		QUERY_ATTR_IDN##_uname, index, 0, &value);		\
+	if (ufshcd_is_qword_attr(QUERY_ATTR_IDN##_uname))		\
+		ret = ufshcd_query_attr_qword(hba,			\
+			UPIU_QUERY_OPCODE_READ_ATTR,			\
+			QUERY_ATTR_IDN##_uname,				\
+			index, 0, &qword_value);			\
+	else								\
+		ret = ufshcd_query_attr(hba,				\
+			UPIU_QUERY_OPCODE_READ_ATTR,			\
+			QUERY_ATTR_IDN##_uname, index, 0, &value);	\
 	ufshcd_rpm_put_sync(hba);					\
 	if (ret) {							\
 		ret = -EINVAL;						\
 		goto out;						\
 	}								\
-	ret = sysfs_emit(buf, "0x%08X\n", value);			\
+	if (ufshcd_is_qword_attr(QUERY_ATTR_IDN##_uname))		\
+		ret = sysfs_emit(buf, "0x%016llX\n", qword_value);	\
+	else								\
+		ret = sysfs_emit(buf, "0x%08X\n", value);		\
 out:									\
 	up(&hba->host_sem);						\
 	return ret;							\
diff --git a/drivers/ufs/core/ufshcd-priv.h b/drivers/ufs/core/ufshcd-priv.h
index 0a72148cb053..ed1adeb22ec6 100644
--- a/drivers/ufs/core/ufshcd-priv.h
+++ b/drivers/ufs/core/ufshcd-priv.h
@@ -60,6 +60,8 @@ int ufshcd_query_attr_retry(struct ufs_hba *hba, enum query_opcode opcode,
 			    u32 *attr_val);
 int ufshcd_query_attr(struct ufs_hba *hba, enum query_opcode opcode,
 		      enum attr_idn idn, u8 index, u8 selector, u32 *attr_val);
+int ufshcd_query_attr_qword(struct ufs_hba *hba, enum query_opcode opcode,
+			    enum attr_idn idn, u8 index, u8 sel, u64 *attr_val);
 int ufshcd_query_flag(struct ufs_hba *hba, enum query_opcode opcode,
 	enum flag_idn idn, u8 index, bool *flag_res);
 void ufshcd_auto_hibern8_update(struct ufs_hba *hba, u32 ahit);
@@ -106,7 +108,6 @@ int ufshcd_exec_raw_upiu_cmd(struct ufs_hba *hba,
 			     enum query_opcode desc_op);
 
 int ufshcd_wb_toggle(struct ufs_hba *hba, bool enable);
-int ufshcd_read_device_lvl_exception_id(struct ufs_hba *hba, u64 *exception_id);
 
 int ufshcd_uic_tx_eqtr(struct ufs_hba *hba, int gear);
 void ufshcd_apply_valid_tx_eq_settings(struct ufs_hba *hba);
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 4805e40ed4d7..c92e0409c793 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -3611,6 +3611,67 @@ int ufshcd_query_attr_retry(struct ufs_hba *hba,
 	return ret;
 }
 
+/**
+ * ufshcd_query_attr_qword - Function of sending query requests for quad-word attributes
+ * @hba: per-adapter instance
+ * @opcode: attribute opcode
+ * @idn: attribute idn to access
+ * @index: index field
+ * @sel: selector field
+ * @attr_val: the attribute value after the query request completes
+ *
+ * Return: 0 for success, non-zero in case of failure.
+ */
+int ufshcd_query_attr_qword(struct ufs_hba *hba, enum query_opcode opcode,
+			    enum attr_idn idn, u8 index, u8 sel, u64 *attr_val)
+{
+	struct utp_upiu_query_v4_0 *upiu_req;
+	struct utp_upiu_query_v4_0 *upiu_resp;
+	struct ufs_query_req *request = NULL;
+	struct ufs_query_res *response = NULL;
+	int err;
+
+	if (!attr_val) {
+		dev_err(hba->dev, "%s: attribute value required for opcode 0x%x\n",
+			__func__, opcode);
+		return -EINVAL;
+	}
+
+	ufshcd_dev_man_lock(hba);
+
+	ufshcd_init_query(hba, &request, &response, opcode, idn, index, sel);
+
+	switch (opcode) {
+	case UPIU_QUERY_OPCODE_WRITE_ATTR:
+		request->query_func = UPIU_QUERY_FUNC_STANDARD_WRITE_REQUEST;
+		upiu_req = (struct utp_upiu_query_v4_0 *)&request->upiu_req;
+		put_unaligned_be64(*attr_val, &upiu_req->osf3);
+		break;
+	case UPIU_QUERY_OPCODE_READ_ATTR:
+		request->query_func = UPIU_QUERY_FUNC_STANDARD_READ_REQUEST;
+		break;
+	default:
+		dev_err(hba->dev, "%s: Expected query attr opcode but got = 0x%.2x\n",
+			__func__, opcode);
+		err = -EINVAL;
+		goto out_unlock;
+	}
+
+	err = ufshcd_exec_dev_cmd(hba, DEV_CMD_TYPE_QUERY, dev_cmd_timeout);
+	if (err) {
+		dev_err(hba->dev, "%s: opcode 0x%.2x for idn %d failed, index %d, selector %d, err = %d\n",
+			__func__, opcode, idn, index, sel, err);
+		goto out_unlock;
+	}
+
+	upiu_resp = (struct utp_upiu_query_v4_0 *)response;
+	*attr_val = get_unaligned_be64(&upiu_resp->osf3);
+
+out_unlock:
+	ufshcd_dev_man_unlock(hba);
+	return err;
+}
+
 /*
  * Return: 0 upon success; > 0 in case the UFS device reported an OCS error;
  * < 0 if another error occurred.
@@ -6224,46 +6285,6 @@ static void ufshcd_bkops_exception_event_handler(struct ufs_hba *hba)
 				__func__, err);
 }
 
-/*
- * Return: 0 upon success; > 0 in case the UFS device reported an OCS error;
- * < 0 if another error occurred.
- */
-int ufshcd_read_device_lvl_exception_id(struct ufs_hba *hba, u64 *exception_id)
-{
-	struct utp_upiu_query_v4_0 *upiu_resp;
-	struct ufs_query_req *request = NULL;
-	struct ufs_query_res *response = NULL;
-	int err;
-
-	if (hba->dev_info.wspecversion < 0x410)
-		return -EOPNOTSUPP;
-
-	ufshcd_hold(hba);
-	mutex_lock(&hba->dev_cmd.lock);
-
-	ufshcd_init_query(hba, &request, &response,
-			  UPIU_QUERY_OPCODE_READ_ATTR,
-			  QUERY_ATTR_IDN_DEV_LVL_EXCEPTION_ID, 0, 0);
-
-	request->query_func = UPIU_QUERY_FUNC_STANDARD_READ_REQUEST;
-
-	err = ufshcd_exec_dev_cmd(hba, DEV_CMD_TYPE_QUERY, dev_cmd_timeout);
-
-	if (err) {
-		dev_err(hba->dev, "%s: failed to read device level exception %d\n",
-			__func__, err);
-		goto out;
-	}
-
-	upiu_resp = (struct utp_upiu_query_v4_0 *)response;
-	*exception_id = get_unaligned_be64(&upiu_resp->osf3);
-out:
-	mutex_unlock(&hba->dev_cmd.lock);
-	ufshcd_release(hba);
-
-	return err;
-}
-
 static int __ufshcd_wb_toggle(struct ufs_hba *hba, bool set, enum flag_idn idn)
 {
 	u8 index;
@@ -9113,35 +9134,20 @@ static int ufshcd_device_params_init(struct ufs_hba *hba)
 
 static void ufshcd_set_timestamp_attr(struct ufs_hba *hba)
 {
-	int err;
-	struct ufs_query_req *request = NULL;
-	struct ufs_query_res *response = NULL;
 	struct ufs_dev_info *dev_info = &hba->dev_info;
-	struct utp_upiu_query_v4_0 *upiu_data;
+	u64 ts_ns;
+	int err;
 
 	if (dev_info->wspecversion < 0x400 ||
 	    hba->dev_quirks & UFS_DEVICE_QUIRK_NO_TIMESTAMP_SUPPORT)
 		return;
 
-	ufshcd_dev_man_lock(hba);
-
-	ufshcd_init_query(hba, &request, &response,
-			  UPIU_QUERY_OPCODE_WRITE_ATTR,
-			  QUERY_ATTR_IDN_TIMESTAMP, 0, 0);
-
-	request->query_func = UPIU_QUERY_FUNC_STANDARD_WRITE_REQUEST;
-
-	upiu_data = (struct utp_upiu_query_v4_0 *)&request->upiu_req;
-
-	put_unaligned_be64(ktime_get_real_ns(), &upiu_data->osf3);
-
-	err = ufshcd_exec_dev_cmd(hba, DEV_CMD_TYPE_QUERY, dev_cmd_timeout);
-
+	ts_ns = ktime_get_real_ns();
+	err = ufshcd_query_attr_qword(hba, UPIU_QUERY_OPCODE_WRITE_ATTR,
+				      QUERY_ATTR_IDN_TIMESTAMP, 0, 0, &ts_ns);
 	if (err)
 		dev_err(hba->dev, "%s: failed to set timestamp %d\n",
 			__func__, err);
-
-	ufshcd_dev_man_unlock(hba);
 }
 
 /**
-- 
2.34.1

[PATCH v2 2/2] scsi: ufs: core: Add support to retrieve and store TX Equalization settings

[Can Guo]

Add support for UFS v5.0 JEDEC attributes qTxEQGnSettings and
wTxEQGnSettingsExt to enable persistent storage and retrieval of
optimal TX Equalization settings.

This provides a fast-path for TX Equalization by reusing previously
stored optimal settings, avoiding TX Equalization Training (EQTR)
procedures during subsequent Power Mode changes.

When no valid TX Equalization settings are found, fall back to full TX
EQTR procedures and optionally save the results for future use.

The validity of one set of TX Equalization settings is indicated by
Bit[15] in wTxEQGnSettingsExt.

Signed-off-by: Can Guo <can.guo@oss.qualcomm.com>
---
 drivers/ufs/core/ufs-txeq.c    | 287 +++++++++++++++++++++++++++++++++
 drivers/ufs/core/ufshcd-priv.h |   2 +
 drivers/ufs/core/ufshcd.c      |   5 +
 include/ufs/ufs.h              |   2 +
 include/ufs/ufshcd.h           |   2 +
 5 files changed, 298 insertions(+)

diff --git a/drivers/ufs/core/ufs-txeq.c b/drivers/ufs/core/ufs-txeq.c
index b2dc89124353..4b264adfdf49 100644
--- a/drivers/ufs/core/ufs-txeq.c
+++ b/drivers/ufs/core/ufs-txeq.c
@@ -14,6 +14,9 @@
 #include <ufs/unipro.h>
 #include "ufshcd-priv.h"
 
+#define TX_EQ_SETTING_MASK		0x7
+#define TX_EQ_SETTINGS_VALID_BIT	BIT(15)
+
 static bool use_adaptive_txeq;
 module_param(use_adaptive_txeq, bool, 0644);
 MODULE_PARM_DESC(use_adaptive_txeq, "Find and apply optimal TX Equalization settings before changing Power Mode (default: false)");
@@ -40,6 +43,28 @@ static bool txeq_presets_selected[UFS_TX_EQ_PRESET_MAX] = {[0 ... (UFS_TX_EQ_PRE
 module_param_array(txeq_presets_selected, bool, NULL, 0644);
 MODULE_PARM_DESC(txeq_presets_selected, "Use only the selected Presets out of the 8 TX Equalization Presets for TX EQTR");
 
+static int txeq_setting_sel_set(const char *val, const struct kernel_param *kp)
+{
+	return param_set_uint_minmax(val, kp, 0, 1);
+}
+
+static const struct kernel_param_ops txeq_setting_sel_ops = {
+	.set = txeq_setting_sel_set,
+	.get = param_get_uint,
+};
+
+static unsigned int txeq_setting_sel;
+module_param_cb(txeq_setting_sel, &txeq_setting_sel_ops, &txeq_setting_sel, 0644);
+MODULE_PARM_DESC(txeq_setting_sel, "The qTxEQGnSettings and wTxEQGnSettingsExt Attributes selector used to retrieve and store TX Equalization settings");
+
+static bool retrieve_txeq_setting = true;
+module_param(retrieve_txeq_setting, bool, 0644);
+MODULE_PARM_DESC(retrieve_txeq_setting, "Retrieve TX Equalization settings from qTxEQGnSettings and wTxEQGnSettingsExt Attributes (default: true)");
+
+static bool store_txeq_setting = true;
+module_param(store_txeq_setting, bool, 0644);
+MODULE_PARM_DESC(store_txeq_setting, "Store the optimal TX Equalization settings to qTxEQGnSettings and wTxEQGnSettingsExt Attributes (default: true)");
+
 /*
  * ufs_tx_eq_preset - Table of minimum required list of presets.
  *
@@ -117,6 +142,126 @@ static const u32 pa_tx_eq_setting[UFS_HS_GEAR_MAX] = {
 	PA_TXEQG6SETTING
 };
 
+/*
+ * Decode Device TX Equalization PreShoot value based on qTxEQGnSettings bit assignment:
+ * bit[3:0]: Device TX Logical LANE 0 PreShoot
+ * bit[7:4]: Device TX Logical LANE 1 PreShoot
+ */
+static inline u8 tx_eq_device_preshoot_decode(u64 eq, u8 lane)
+{
+	return (u8)((eq >> (lane * TX_HS_PRESHOOT_SHIFT)) & TX_EQ_SETTING_MASK);
+}
+
+/*
+ * Decode Device TX Equalization DeEmphasis value based on qTxEQGnSettings bit assignment:
+ * bit[19:16]: Device TX Logical LANE 0 DeEmphasis
+ * bit[23:20]: Device TX Logical LANE 1 DeEmphasis
+ */
+static inline u8 tx_eq_device_deemphasis_decode(u64 eq, u8 lane)
+{
+	return (u8)((eq >> (lane * TX_HS_DEEMPHASIS_SHIFT + 16)) & TX_EQ_SETTING_MASK);
+}
+
+/*
+ * Decode Host TX Equalization PreShoot value based on qTxEQGnSettings bit assignment:
+ * bit[35:32]: Host TX Logical LANE 0 PreShoot
+ * bit[39:36]: Host TX Logical LANE 1 PreShoot
+ */
+static inline u8 tx_eq_host_preshoot_decode(u64 eq, u8 lane)
+{
+	return (u8)((eq >> (lane * TX_HS_PRESHOOT_SHIFT + 32)) & TX_EQ_SETTING_MASK);
+}
+
+/*
+ * Decode Host TX Equalization DeEmphasis value based on qTxEQGnSettings bit assignment:
+ * bit[51:48]: Host TX Logical LANE 0 DeEmphasis
+ * bit[55:52]: Host TX Logical LANE 1 DeEmphasis
+ */
+static inline u8 tx_eq_host_deemphasis_decode(u64 eq, u8 lane)
+{
+	return (u8)((eq >> (lane * TX_HS_DEEMPHASIS_SHIFT + 48)) & TX_EQ_SETTING_MASK);
+}
+
+/*
+ * Decode Device TX precode_en indication based on wTxEQGnSettingsExt bit assignment:
+ * bit[0]: PreCodeEn for Device TX Logical LANE 0
+ * bit[1]: PreCodeEn for Device TX Logical LANE 1
+ */
+static inline bool tx_eq_device_precode_en_decode(u16 eq_ext, u8 lane)
+{
+	return eq_ext & BIT(lane);
+}
+
+/*
+ * Decode Host TX precode_en indication based on wTxEQGnSettingsExt bit assignment:
+ * bit[4]: PreCodeEn for Device RX Logical LANE 0
+ * bit[5]: PreCodeEn for Device RX Logical LANE 1
+ */
+static inline bool tx_eq_host_precode_en_decode(u16 eq_ext, u8 lane)
+{
+	return eq_ext & BIT(lane + 4);
+}
+
+/*
+ * Encode Device TX Equalization PreShoot value based on qTxEQGnSettings bit assignment:
+ * bit[3:0]: Device TX Logical LANE 0 PreShoot
+ * bit[7:4]: Device TX Logical LANE 1 PreShoot
+ */
+static inline u64 tx_eq_device_preshoot_encode(u64 val, u8 lane)
+{
+	return (val & TX_EQ_SETTING_MASK) << (lane * TX_HS_PRESHOOT_SHIFT);
+}
+
+/*
+ * Encode Device TX Equalization DeEmphasis value based on qTxEQGnSettings bit assignment:
+ * bit[19:16]: Device TX Logical LANE 0 DeEmphasis
+ * bit[23:20]: Device TX Logical LANE 1 DeEmphasis
+ */
+static inline u64 tx_eq_device_deemphasis_encode(u64 val, u8 lane)
+{
+	return (val & TX_EQ_SETTING_MASK) << (lane * TX_HS_DEEMPHASIS_SHIFT + 16);
+}
+
+/*
+ * Encode Host TX Equalization PreShoot value based on qTxEQGnSettings bit assignment:
+ * bit[35:32]: Host TX Logical LANE 0 PreShoot
+ * bit[39:36]: Host TX Logical LANE 1 PreShoot
+ */
+static inline u64 tx_eq_host_preshoot_encode(u64 val, u8 lane)
+{
+	return (val & TX_EQ_SETTING_MASK) << (lane * TX_HS_PRESHOOT_SHIFT + 32);
+}
+
+/*
+ * Encode Host TX Equalization DeEmphasis value based on qTxEQGnSettings bit assignment:
+ * bit[51:48]: Host TX Logical LANE 0 DeEmphasis
+ * bit[55:52]: Host TX Logical LANE 1 DeEmphasis
+ */
+static inline u64 tx_eq_host_deemphasis_encode(u64 val, u8 lane)
+{
+	return (val & TX_EQ_SETTING_MASK) << (lane * TX_HS_DEEMPHASIS_SHIFT + 48);
+}
+
+/*
+ * Encode Device precode_en based on wTxEQGnSettingsExt bit assignment:
+ * bit[0]: PreCodeEn for Device TX Logical LANE 0
+ * bit[1]: PreCodeEn for Device TX Logical LANE 1
+ */
+static inline u16 tx_eq_device_precode_en_encode(bool en, u8 lane)
+{
+	return (u16)en << lane;
+}
+
+/*
+ * Encode Host precode_en based on wTxEQGnSettingsExt bit assignment:
+ * bit[4]: PreCodeEn for Device RX Logical LANE 0
+ * bit[5]: PreCodeEn for Device RX Logical LANE 1
+ */
+static inline u16 tx_eq_host_precode_en_encode(bool en, u8 lane)
+{
+	return (u16)en << (lane + 4);
+}
+
 /**
  * ufshcd_configure_precoding - Configure Pre-Coding for all active lanes
  * @hba: per adapter instance
@@ -1164,6 +1309,7 @@ int ufshcd_config_tx_eq_settings(struct ufs_hba *hba,
 
 		/* Mark TX Equalization settings as valid */
 		params->is_valid = true;
+		params->is_trained = true;
 		params->is_applied = false;
 	}
 
@@ -1291,3 +1437,144 @@ int ufshcd_retrain_tx_eq(struct ufs_hba *hba, u32 gear)
 
 	return ret;
 }
+
+/**
+ * ufshcd_extract_tx_eq_settings_attrs - Extract TX Equalization settings from UFS attributes
+ * @hba: per adapter instance
+ * @gear: target gear
+ *
+ * This function extracts previously stored TX Equalization settings from UFS
+ * attributes qTxEQGnSettings and wTxEQGnSettingsExt. These attributes contain
+ * the optimal TX Equalization parameters (PreShoot, DeEmphasis, and PreCoding
+ * enable) that were determined during a previous EQTR procedure.
+ *
+ * The function reads:
+ * 1. qTxEQGnSettings (64-bit): Main attribute containing PreShoot and
+ *    DeEmphasis values for both host and device TX lanes
+ * 2. wTxEQGnSettingsExt (16-bit): Extended attribute containing PreCoding
+ *    enable flags and validity indicator
+ */
+static void ufshcd_extract_tx_eq_settings_attrs(struct ufs_hba *hba, u8 gear)
+{
+	struct ufshcd_tx_eq_params *params;
+	u32 lane, eq_ext;
+	int ret;
+	u64 eq;
+
+	ret = ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_READ_ATTR,
+				QUERY_ATTR_IDN_TX_EQ_GN_SETTINGS_EXT, gear - 1,
+				(u8)txeq_setting_sel, &eq_ext);
+	if (ret)
+		return;
+
+	dev_dbg(hba->dev, "%s: HS-G%u wTxEQGnSettingsExt (Selector %u) = 0x%08x\n",
+		__func__, gear, txeq_setting_sel, eq_ext);
+
+	if (!(eq_ext & TX_EQ_SETTINGS_VALID_BIT))
+		return;
+
+	ret = ufshcd_query_attr_qword(hba, UPIU_QUERY_OPCODE_READ_ATTR,
+				      QUERY_ATTR_IDN_TX_EQ_GN_SETTINGS,
+				      gear - 1, (u8)txeq_setting_sel, &eq);
+	if (ret)
+		return;
+
+	dev_dbg(hba->dev, "%s: HS-G%u qTxEQGnSettings (Selector %u) = 0x%016llx\n",
+		__func__, gear, txeq_setting_sel, eq);
+
+	params = &hba->tx_eq_params[gear - 1];
+
+	for (lane = 0; lane < UFS_MAX_LANES; lane++) {
+		params->host[lane].preshoot = tx_eq_host_preshoot_decode(eq, lane);
+		params->host[lane].deemphasis = tx_eq_host_deemphasis_decode(eq, lane);
+		params->host[lane].precode_en = tx_eq_host_precode_en_decode(eq_ext, lane);
+
+		params->device[lane].preshoot = tx_eq_device_preshoot_decode(eq, lane);
+		params->device[lane].deemphasis = tx_eq_device_deemphasis_decode(eq, lane);
+		params->device[lane].precode_en = tx_eq_device_precode_en_decode(eq_ext, lane);
+	}
+
+	params->is_valid = true;
+}
+
+void ufshcd_retrieve_tx_eq_settings(struct ufs_hba *hba)
+{
+	u8 gear = (u8)adaptive_txeq_gear;
+
+	if (!hba->max_pwr_info.is_valid || !ufshcd_is_tx_eq_supported(hba) ||
+	    !use_adaptive_txeq || !retrieve_txeq_setting)
+		return;
+
+	for (; gear <= UFS_HS_GEAR_MAX; gear++)
+		ufshcd_extract_tx_eq_settings_attrs(hba, gear);
+}
+
+/**
+ * ufshcd_update_tx_eq_settings_attrs - Update TX EQ settings in UFS attributes
+ * @hba: per adapter instance
+ * @gear: target gear
+ *
+ * This function stores the optimal TX Equalization settings obtained from
+ * TX EQTR procedure into UFS device attributes for future fast-path retrieval.
+ * The settings are stored in two complementary attributes:
+ *
+ * 1. qTxEQGnSettings (64-bit): Main attribute containing PreShoot and
+ *    DeEmphasis values for both host and device TX lanes
+ * 2. wTxEQGnSettingsExt (16-bit): Extended attribute containing PreCoding
+ *    enable flags and validity indicator
+ */
+static void ufshcd_update_tx_eq_settings_attrs(struct ufs_hba *hba, u8 gear)
+{
+	struct ufshcd_tx_eq_params *params;
+	u32 lane, eq_ext = 0;
+	u64 eq = 0;
+	int ret;
+
+	params = &hba->tx_eq_params[gear - 1];
+	if (!params->is_valid || !params->is_trained)
+		return;
+
+	for (lane = 0; lane < UFS_MAX_LANES; lane++) {
+		eq |= tx_eq_host_preshoot_encode((u64)params->host[lane].preshoot, lane);
+		eq |= tx_eq_host_deemphasis_encode((u64)params->host[lane].deemphasis, lane);
+		eq_ext |= tx_eq_host_precode_en_encode(params->host[lane].precode_en, lane);
+
+		eq |= tx_eq_device_preshoot_encode((u64)params->device[lane].preshoot, lane);
+		eq |= tx_eq_device_deemphasis_encode((u64)params->device[lane].deemphasis, lane);
+		eq_ext |= tx_eq_device_precode_en_encode(params->device[lane].precode_en, lane);
+	}
+
+	/* Set validity flag to indicate valid settings are stored */
+	eq_ext |= TX_EQ_SETTINGS_VALID_BIT;
+
+	/* Write qTxEQGnSettings */
+	ret = ufshcd_query_attr_qword(hba, UPIU_QUERY_OPCODE_WRITE_ATTR,
+				      QUERY_ATTR_IDN_TX_EQ_GN_SETTINGS,
+				      gear - 1, (u8)txeq_setting_sel, &eq);
+	if (ret)
+		return;
+
+	/* Write wTxEQGnSettingsExt */
+	ret = ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_WRITE_ATTR,
+				QUERY_ATTR_IDN_TX_EQ_GN_SETTINGS_EXT, gear - 1,
+				(u8)txeq_setting_sel, &eq_ext);
+	if (ret)
+		return;
+
+	dev_dbg(hba->dev, "%s: Saved HS-G%u qTxEQGnSettings (Selector %u) = 0x%016llx\n",
+		__func__, gear, txeq_setting_sel, eq);
+	dev_dbg(hba->dev, "%s: Saved HS-G%u wTxEQGnSettingsExt (Selector %u) = 0x%08x\n",
+		__func__, gear, txeq_setting_sel, eq_ext);
+}
+
+void ufshcd_store_tx_eq_settings(struct ufs_hba *hba)
+{
+	u8 gear = (u8)adaptive_txeq_gear;
+
+	if (!hba->max_pwr_info.is_valid || !ufshcd_is_tx_eq_supported(hba) ||
+	    !use_adaptive_txeq || !store_txeq_setting)
+		return;
+
+	for (; gear <= UFS_HS_GEAR_MAX; gear++)
+		ufshcd_update_tx_eq_settings_attrs(hba, gear);
+}
diff --git a/drivers/ufs/core/ufshcd-priv.h b/drivers/ufs/core/ufshcd-priv.h
index ed1adeb22ec6..70f90d97f217 100644
--- a/drivers/ufs/core/ufshcd-priv.h
+++ b/drivers/ufs/core/ufshcd-priv.h
@@ -118,6 +118,8 @@ void ufshcd_print_tx_eq_params(struct ufs_hba *hba);
 bool ufshcd_is_txeq_presets_used(struct ufs_hba *hba);
 bool ufshcd_is_txeq_preset_selected(u8 preshoot, u8 deemphasis);
 int ufshcd_retrain_tx_eq(struct ufs_hba *hba, u32 gear);
+void ufshcd_retrieve_tx_eq_settings(struct ufs_hba *hba);
+void ufshcd_store_tx_eq_settings(struct ufs_hba *hba);
 
 /* Wrapper functions for safely calling variant operations */
 static inline const char *ufshcd_get_var_name(struct ufs_hba *hba)
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index c92e0409c793..a6026cc4b2f4 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -9128,6 +9128,8 @@ static int ufshcd_device_params_init(struct ufs_hba *hba)
 		dev_err(hba->dev,
 			"%s: Failed getting max supported power mode\n",
 			__func__);
+
+	ufshcd_retrieve_tx_eq_settings(hba);
 out:
 	return ret;
 }
@@ -10748,6 +10750,9 @@ static void ufshcd_wl_shutdown(struct scsi_device *sdev)
 
 	/* Turn on everything while shutting down */
 	ufshcd_rpm_get_sync(hba);
+
+	ufshcd_store_tx_eq_settings(hba);
+
 	scsi_device_quiesce(sdev);
 	shost_for_each_device(sdev, hba->host) {
 		if (sdev == hba->ufs_device_wlun)
diff --git a/include/ufs/ufs.h b/include/ufs/ufs.h
index 602aa34c9822..0d48e137d66d 100644
--- a/include/ufs/ufs.h
+++ b/include/ufs/ufs.h
@@ -191,6 +191,8 @@ enum attr_idn {
 	QUERY_ATTR_IDN_WB_BUF_RESIZE_HINT	= 0x3C,
 	QUERY_ATTR_IDN_WB_BUF_RESIZE_EN		= 0x3D,
 	QUERY_ATTR_IDN_WB_BUF_RESIZE_STATUS	= 0x3E,
+	QUERY_ATTR_IDN_TX_EQ_GN_SETTINGS        = 0x47,
+	QUERY_ATTR_IDN_TX_EQ_GN_SETTINGS_EXT    = 0x48,
 };
 
 /* Descriptor idn for Query requests */
diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h
index cfbc75d8df83..f48d6416e299 100644
--- a/include/ufs/ufshcd.h
+++ b/include/ufs/ufshcd.h
@@ -358,6 +358,7 @@ struct ufshcd_tx_eqtr_record {
  * @eqtr_record: Pointer to TX EQTR record
  * @is_valid: True if parameter contains valid TX Equalization settings
  * @is_applied: True if settings have been applied to UniPro of both sides
+ * @is_trained: True if parameters obtained from TX EQTR procedure
  */
 struct ufshcd_tx_eq_params {
 	struct ufshcd_tx_eq_settings host[UFS_MAX_LANES];
@@ -365,6 +366,7 @@ struct ufshcd_tx_eq_params {
 	struct ufshcd_tx_eqtr_record *eqtr_record;
 	bool is_valid;
 	bool is_applied;
+	bool is_trained;
 };
 
 /**
-- 
2.34.1

Re: [PATCH v2 2/2] scsi: ufs: core: Add support to retrieve and store TX Equalization settings

[Peter Wang (王信友)]

On Fri, 2026-04-24 at 08:14 -0700, Can Guo wrote:
> Add support for UFS v5.0 JEDEC attributes qTxEQGnSettings and
> wTxEQGnSettingsExt to enable persistent storage and retrieval of
> optimal TX Equalization settings.
> 
> This provides a fast-path for TX Equalization by reusing previously
> stored optimal settings, avoiding TX Equalization Training (EQTR)
> procedures during subsequent Power Mode changes.
> 
> When no valid TX Equalization settings are found, fall back to full
> TX
> EQTR procedures and optionally save the results for future use.
> 
> The validity of one set of TX Equalization settings is indicated by
> Bit[15] in wTxEQGnSettingsExt.
> 
> Signed-off-by: Can Guo <can.guo@oss.qualcomm.com>

Reviewed-by: Peter Wang <peter.wang@mediatek.com>

Re: [PATCH v2 1/2] scsi: ufs: core: Introduce function ufshcd_query_attr_qword()

[Bean Huo]

On Fri, 2026-04-24 at 08:14 -0700, Can Guo wrote:
> Introduce a new generic function ufshcd_query_attr_qword() to handle
> quad-word (64-bit) UFS attribute operations. This consolidates the
> handling of 64-bit attributes which was previously scattered across
> multiple specialized functions.

Looks good, clean refactoring that consolidates 64 bits attribute handling.

Reviewed-by: Bean Huo <beanhuo@micron.com>

Re: [PATCH v2 2/2] scsi: ufs: core: Add support to retrieve and store TX Equalization settings

[Bean Huo]

On Fri, 2026-04-24 at 08:14 -0700, Can Guo wrote:
> Add support for UFS v5.0 JEDEC attributes qTxEQGnSettings and
> wTxEQGnSettingsExt to enable persistent storage and retrieval of
> optimal TX Equalization settings.
> 
> This provides a fast-path for TX Equalization by reusing previously
> stored optimal settings, avoiding TX Equalization Training (EQTR)
> procedures during subsequent Power Mode changes.
> 
> When no valid TX Equalization settings are found, fall back to full TX
> EQTR procedures and optionally save the results for future use.
> 
> The validity of one set of TX Equalization settings is indicated by
> Bit[15] in wTxEQGnSettingsExt.

Reviewed-by: Bean Huo <beanhuo@micron.com>

Re: [PATCH v2 0/2] scsi: ufs: Add persistent TX Equalization settings support

[Bart Van Assche]

On 4/24/26 8:14 AM, Can Guo wrote:
> v1 -> v2:
> 1. Incorporated comments from Peter, Bart and Bean.
> 2. Fixed typos and minor coding style issues.
> 3. Converted macros to inline functions.

For the series:

Reviewed-by: Bart Van Assche <bvanassche@acm.org>

Re: [PATCH v2 0/2] scsi: ufs: Add persistent TX Equalization settings support

[Brian Kao]

On Fri, Apr 24, 2026 at 11:18 PM Can Guo <can.guo@oss.qualcomm.com> wrote:

> 2. Add TX EQ settings persistence flow:
>    - Read stored settings from qTxEQGnSettings & wTxEQGnSettingsExt.
>    - Decode and populate per-gear TX EQ parameters.
>    - Use Bit[15] in wTxEQGnSettingsExt as validity indication.
>    - Store trained settings back to these attributes for future reuse.
>

Hi Can Guo

Is using Bit[15] as a validity indicator reliable here? Since this
isn't part of the JEDEC standard—which defines bits [15:6] as Reserved
for Future Use (RFU)
Are there plans to propose this validity indicator in a future
revision of the standard? If so, I would definitely support that
proposal.

Thanks

Re: [PATCH v2 0/2] scsi: ufs: Add persistent TX Equalization settings support

[Can Guo]

Hi Brian,

On 5/8/2026 5:08 PM, Brian Kao wrote:
> On Fri, Apr 24, 2026 at 11:18 PM Can Guo <can.guo@oss.qualcomm.com> wrote:
>
>> 2. Add TX EQ settings persistence flow:
>>     - Read stored settings from qTxEQGnSettings & wTxEQGnSettingsExt.
>>     - Decode and populate per-gear TX EQ parameters.
>>     - Use Bit[15] in wTxEQGnSettingsExt as validity indication.
>>     - Store trained settings back to these attributes for future reuse.
>>
> Hi Can Guo
>
> Is using Bit[15] as a validity indicator reliable here? Since this
> isn't part of the JEDEC standard—which defines bits [15:6] as Reserved
> for Future Use (RFU)
> Are there plans to propose this validity indicator in a future
> revision of the standard? If so, I would definitely support that
> proposal.
Thank you for supporting it. I will use my internal Qualcomm email to 
reach to
you and Bart for discussion from standard point of view. It can be discussed
further during JEDEC committee meeting in Sapporo.

Thanks,
Can Guo.
>
> Thanks