[PATCH v5 00/12] scsi: ufs: Add TX Equalization support for UFS 5.0

[PATCH v5 00/12] scsi: ufs: Add TX Equalization support for UFS 5.0

[Can Guo]

Hi,

The UFS v5.0 and UFSHCI v5.0 standards have published, introducing support
for HS-G6 (46.6 Gbps per lane) through the new UniPro V3.0 interconnect
layer and M-PHY V6.0 physical layer specifications. To achieve reliable
operation at these higher speeds, UniPro V3.0 introduces TX Equalization
and Pre-Coding mechanisms that are essential for signal integrity.

This patch series implements TX Equalization support in the UFS core
driver as specified in UFSHCI v5.0, along with the necessary vendor
operations and a reference implementation for Qualcomm UFS host
controllers.

Background
==========

TX Equalization is a signal conditioning technique that compensates for
channel impairments at high data rates (HS-G4 through HS-G6). It works
by adjusting two key parameters:

- PreShoot: Pre-emphasis applied before the main signal transition
- DeEmphasis: De-emphasis applied after the main signal transition

UniPro V3.0 defines TX Equalization Training (EQTR) procedure to
automatically discover optimal TX Equalization settings. The EQTR
procedure:

1. Starts from the most reliable link state (HS-G1)
2. Iterates through all possible PreShoot and DeEmphasis combinations
3. Evaluates signal quality using Figure of Merit (FOM) measurements
4. Selects the best settings for both host and device TX lanes

For HS-G6, Pre-Coding is also introduced to further improve signal
quality. Pre-Coding must be enabled on both transmitter and receiver
when the RX_FOM indicates it is required.

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

The implementation follows the UFSHCI v5.0 specification and consists of:

Core Infrastructure (Patches 1-6):
- New vops callback negotiate_pwr_mode() to allow vendors to negotiate
  power mode parameters before applying TX Equalization settings
- Support for HS-G6 gear enumeration
- Complete TX EQTR procedure implementation in ufs-txeq.c
- Debugfs interface for TX Equalization parameter inspection and manual
  retraining
- Module parameters for adaptive TX Equalization control

Qualcomm Implementation (Patches 7-11):
- PHY-specific configurations for TX EQTR procedure
- Vendor-specific FOM measurement support
- TX Equalization settings application
- Enable TX Equalization for HW version 0x7 and onwards

The implementation is designed to be vendor-agnostic, with platform-
specific details handled through the vops callbacks. Other vendors can
add support by implementing the three new vops:

- tx_eqtr_notify(): Called before/after TX EQTR for vendor setup
- apply_tx_eqtr_settings(): Apply vendor-specific PHY configurations
- get_rx_fom(): Retrieve vendor-specific FOM measurements if needed

Module Parameters
=================

The implementation provides several module parameters for flexibility:

- use_adaptive_txeq: Enable/disable adaptive TX Equalization (default: false)
- adaptive_txeq_gear: Minimum gear for adaptive TX EQ (default: HS-G6)
- use_txeq_presets: Use only the 8 standaird presets (default: false)
- txeq_presets_selected[]: Select specific presets for EQTR

Testing
=======

This patch series has been tested on Qualcomm platforms with UFS 5.0
devices, validating:

- Successful TX EQTR completion for HS-G6
- Proper FOM evaluation and optimal settings selection
- Pre-Coding enablement for HS-G6
- Power mode changes with TX Equalization settings applied
- Report of TX Equalization settings via debugfs entries
- Report of TX EQTR histories via debug entries (see next section)
- Re-training TX Equalization via debugfs entry

Example of TX EQTR history
==========================

# cat /sys/kernel/debug/ufshcd/*ufshcd*/tx_eq_hs_gear6/device_tx_eqtr_record
Device TX EQTR record summary -
Target Power Mode: HS-G6, Rate-B
Most recent record index: 2
Most recent record timestamp: 219573378 us

TX Lane 0 FOM - PreShoot\DeEmphasis
\       0        1        2        3        4        5        6        7
0      50       70       65        -        -        -        -        x
1       x        x        x        x        x        x        x        x
2     100       90       70        -        -        -        -        x
3       x        x        x        x        x        x        x        x
4      95       90        -        -        -        -        -        x
5       -        -        -        -        -        -        -        x
6       x        x        x        x        x        x        x        x
7       x        x        x        x        x        x        x        x

TX Lane 1 FOM - PreShoot\DeEmphasis
\       0        1        2        3        4        5        6        7
0      50       70       60        -        -        -        -        x
1       x        x        x        x        x        x        x        x
2     100       80       65        -        -        -        -        x
3       x        x        x        x        x        x        x        x
4      95       85        -        -        -        -        -        x
5       -        -        -        -        -        -        -        x
6       x        x        x        x        x        x        x        x
7       x        x        x        x        x        x        x        x

Patch Structure
===============

Patches 1-3: Preparatory changes for power mode negotiation and HS-G6
Patch 4: Core TX Equalization and EQTR implementation
Patches 5-7: Debugfs support for TX Equalization
Patches 8-12: Qualcomm vendor implementation

Next
====

One more series has been developed to enhance TX Equalization support,
which will be submitted for review after this series is accepted:

- Provide board specific (static) TX Equalization settings from DTS
- Parse static TX Equalization settings from DTS if provided
- Apply static TX Equalization settings if use_adaptive_txeq is disabled
- Add support for UFS v5.0 attributes qTxEQGnSettings & wTxEQGnSettingsExt
- Enable persistent storage and retrieval of optimal TX Equalization settings

v4 -> v5:
1. Addressed comments from Bean in patch 7, returned -EINVAL when
   negotiated gear != requested gear in function ufshcd_retrain_tx_eq().
2. Addressed comments from Peter in patch 4, moved usage of
   &hba->tx_eq_params[gear - 1] after checks on gear and improved the
   checks on gear in function ufshcd_config_tx_eq_settings().

v3 -> v4:
1. Incorporated comments from Bart and Peter.
2. In patch 1, removed redundant checks on dev_req_params
3. In patch 1, moved error prints out of vops negotiate_pwr_mode()
4. In patch 1, removed vops implemenation ufs_versal2_negotiate_pwr_mode(),
   sprd_ufs_negotiate_pwr_mode() and ufs_intel_lkf_negotiate_pwr_mode() as
   they are simply doing memcpy().
5. In patch 3, initialize UFS_HS_GEAR_MAX as UFS_HS_G6. 
6. In patch 4, adjusted places where UFS_HS_GEAR_MAX is used.
7. In patch 4, defined inline func ufs_hs_rate_to_str() instead of macro.
8. In patch 4, changed default value of use_txeq_presets to 'false'.
8. In patch 4, optimized ufshcd_tx_eq_params and ufshcd_tx_eq_settings.
9. In patch 4, optimized memory usage of ufshcd_tx_eq_params.
10. In patch 5, updated places which use fields in ufshcd_tx_eq_params.
11. In patch 7, used 'retrain' instead of 'refresh'.
12. In patch 10, introduced a few macros.

v2 -> v3:
1. Incorporated comments from Bart, Bean and Mani.
2. In patch 4, made ufshcd_config_pwr_mode() ignore TX EQTR error.
3. Added patch 6 to introduce helpers to pause/resume command processing.
4. In patch 7, changed debugfs entry to 'tx_eq_ctrl' and used 'refresh'
   as input to trigger TX Equalization refreshing.
5. In patch 7, renamed ufshcd_retrain_tx_eq() to ufshcd_refresh_tx_eq().
6. Fixed typos and coding style issues.

v1 -> v2:
1. Incorporated Bart's comments.
2. Fixed typos and coding style issues.
3. Added enum ufshcd_pmc_policy and use enum instead of boolen parameter.
4. Updated TX Equalization debugfs entries structure.
5. Extracted ufshcd_pause/resume_command_processing() in ufshcd.c.
6. Updated sequence in Qualcomm's vops get_rx_fom() implementation.

Can Guo (12):
  scsi: ufs: core: Introduce a new ufshcd vops negotiate_pwr_mode()
  scsi: ufs: core: Pass force_pmc to ufshcd_config_pwr_mode() as a
    parameter
  scsi: ufs: core: Add UFS_HS_G6 and UFS_HS_GEAR_MAX to enum
    ufs_hs_gear_tag
  scsi: ufs: core: Add support for TX Equalization
  scsi: ufs: core: Add debugfs entries for TX Equalization params
  scsi: ufs: core: Add helpers to pause and resume command processing
  scsi: ufs: core: Add support to retrain TX Equalization via debugfs
  scsi: ufs: ufs-qcom: Fixup PAM-4 TX L0_L1_L2_L3 adaptation pattern
    length
  scsi: ufs: ufs-qcom: Implement vops tx_eqtr_notify()
  scsi: ufs: ufs-qcom: Implement vops get_rx_fom()
  scsi: ufs: ufs-qcom: Implement vops apply_tx_eqtr_settings()
  scsi: ufs: ufs-qcom: Enable TX Equalization

 drivers/ufs/core/Makefile          |    2 +-
 drivers/ufs/core/ufs-debugfs.c     |  290 +++++++
 drivers/ufs/core/ufs-txeq.c        | 1293 ++++++++++++++++++++++++++++
 drivers/ufs/core/ufshcd-priv.h     |   59 +-
 drivers/ufs/core/ufshcd.c          |  192 ++++-
 drivers/ufs/host/ufs-amd-versal2.c |    3 -
 drivers/ufs/host/ufs-exynos.c      |   34 +-
 drivers/ufs/host/ufs-hisi.c        |   23 +-
 drivers/ufs/host/ufs-mediatek.c    |   40 +-
 drivers/ufs/host/ufs-qcom.c        |  591 ++++++++++++-
 drivers/ufs/host/ufs-qcom.h        |   42 +
 drivers/ufs/host/ufs-sprd.c        |    3 -
 drivers/ufs/host/ufshcd-pci.c      |    7 +-
 include/ufs/ufshcd.h               |  174 +++-
 include/ufs/unipro.h               |  141 ++-
 15 files changed, 2779 insertions(+), 115 deletions(-)
 create mode 100644 drivers/ufs/core/ufs-txeq.c

-- 
2.34.1

[PATCH v5 01/12] scsi: ufs: core: Introduce a new ufshcd vops negotiate_pwr_mode()

[Can Guo]

Most vendor specific implemenations of vops pwr_change_notify(PRE_CHANGE)
are fulfilling two things at once:
- Vendor specific target power mode negotiation
- Vendor specific power mode change preparation

When TX Equalization is added into consideration, before power mode change
to a target power mode, TX Equalization Training (EQTR) needs be done for
that target power mode. In addition, UFSHCI spec requires to start TX EQTR
from HS-G1 (the most reliable High Speed Gear).

Adding TX EQTR before pwr_change_notify(PRE_CHANGE) is not applicable
because we don't know the negotiated power mode yet.

Adding TX EQTR post pwr_change_notify(PRE_CHANGE) is inappropriate
because pwr_change_notify(PRE_CHANGE) has finished preparation for a power
mode change to negotiated power mode, yet we are changing power mode to
HS-G1 for TX EQTR.

Add a new vops negotiate_pwr_mode() so that vendor specific power mode
negotiation can be fulfilled in its vendor specific implementations.
Later on, TX EQTR can be added post vops negotiate_pwr_mode() and before
vops pwr_change_notify(PRE_CHANGE).

Reviewed-by: Bean Huo <beanhuo@micron.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Can Guo <can.guo@oss.qualcomm.com>
---
 drivers/ufs/core/ufshcd-priv.h     | 14 +++++-
 drivers/ufs/core/ufshcd.c          | 70 ++++++++++++++++++++++++------
 drivers/ufs/host/ufs-amd-versal2.c |  3 --
 drivers/ufs/host/ufs-exynos.c      | 34 +++++++--------
 drivers/ufs/host/ufs-hisi.c        | 23 +++++-----
 drivers/ufs/host/ufs-mediatek.c    | 40 ++++++++---------
 drivers/ufs/host/ufs-qcom.c        | 24 +++++-----
 drivers/ufs/host/ufs-sprd.c        |  3 --
 drivers/ufs/host/ufshcd-pci.c      |  6 +--
 include/ufs/ufshcd.h               | 17 +++++---
 10 files changed, 143 insertions(+), 91 deletions(-)

diff --git a/drivers/ufs/core/ufshcd-priv.h b/drivers/ufs/core/ufshcd-priv.h
index 7d6d19361af9..3b6958d9297a 100644
--- a/drivers/ufs/core/ufshcd-priv.h
+++ b/drivers/ufs/core/ufshcd-priv.h
@@ -167,14 +167,24 @@ static inline int ufshcd_vops_link_startup_notify(struct ufs_hba *hba,
 	return 0;
 }
 
+static inline int ufshcd_vops_negotiate_pwr_mode(struct ufs_hba *hba,
+						 const struct ufs_pa_layer_attr *dev_max_params,
+						 struct ufs_pa_layer_attr *dev_req_params)
+{
+	if (hba->vops && hba->vops->negotiate_pwr_mode)
+		return hba->vops->negotiate_pwr_mode(hba, dev_max_params,
+					dev_req_params);
+
+	return -ENOTSUPP;
+}
+
 static inline int ufshcd_vops_pwr_change_notify(struct ufs_hba *hba,
 				enum ufs_notify_change_status status,
-				const struct ufs_pa_layer_attr *dev_max_params,
 				struct ufs_pa_layer_attr *dev_req_params)
 {
 	if (hba->vops && hba->vops->pwr_change_notify)
 		return hba->vops->pwr_change_notify(hba, status,
-					dev_max_params, dev_req_params);
+					dev_req_params);
 
 	return -ENOTSUPP;
 }
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 8349fe2090db..91b5d5b02d22 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -335,8 +335,6 @@ static void ufshcd_suspend_clkscaling(struct ufs_hba *hba);
 static int ufshcd_scale_clks(struct ufs_hba *hba, unsigned long freq,
 			     bool scale_up);
 static irqreturn_t ufshcd_intr(int irq, void *__hba);
-static int ufshcd_change_power_mode(struct ufs_hba *hba,
-			     struct ufs_pa_layer_attr *pwr_mode);
 static int ufshcd_setup_hba_vreg(struct ufs_hba *hba, bool on);
 static int ufshcd_setup_vreg(struct ufs_hba *hba, bool on);
 static inline int ufshcd_config_vreg_hpm(struct ufs_hba *hba,
@@ -4662,8 +4660,26 @@ static int ufshcd_get_max_pwr_mode(struct ufs_hba *hba)
 	return 0;
 }
 
-static int ufshcd_change_power_mode(struct ufs_hba *hba,
-			     struct ufs_pa_layer_attr *pwr_mode)
+/**
+ * ufshcd_dme_change_power_mode() - UniPro DME Power Mode change sequence
+ * @hba: per-adapter instance
+ * @pwr_mode: pointer to the target power mode (gear/lane) attributes
+ *
+ * This function handles the low-level DME (Device Management Entity)
+ * configuration required to transition the UFS link to a new power mode. It
+ * performs the following steps:
+ * 1. Checks if the requested mode matches the current state.
+ * 2. Sets M-PHY and UniPro attributes including Gear (PA_RXGEAR/TXGEAR),
+ *    Lanes, Termination, and HS Series (PA_HSSERIES).
+ * 3. Configures default UniPro timeout values (DL_FC0, etc.) unless
+ *    explicitly skipped via quirks.
+ * 4. Triggers the actual hardware mode change via ufshcd_uic_change_pwr_mode().
+ * 5. Updates the HBA's cached power information on success.
+ *
+ * Return: 0 on success, non-zero error code on failure.
+ */
+static int ufshcd_dme_change_power_mode(struct ufs_hba *hba,
+					struct ufs_pa_layer_attr *pwr_mode)
 {
 	int ret;
 
@@ -4747,6 +4763,34 @@ static int ufshcd_change_power_mode(struct ufs_hba *hba,
 	return ret;
 }
 
+/**
+ * ufshcd_change_power_mode() - Change UFS Link Power Mode
+ * @hba: per-adapter instance
+ * @pwr_mode: pointer to the target power mode (gear/lane) attributes
+ *
+ * This function handles the high-level sequence for changing the UFS link
+ * power mode. It triggers vendor-specific pre-change notification,
+ * executes the DME (Device Management Entity) power mode change sequence,
+ * and, upon success, triggers vendor-specific post-change notification.
+ *
+ * Return: 0 on success, non-zero error code on failure.
+ */
+int ufshcd_change_power_mode(struct ufs_hba *hba,
+			     struct ufs_pa_layer_attr *pwr_mode)
+{
+	int ret;
+
+	ufshcd_vops_pwr_change_notify(hba, PRE_CHANGE, pwr_mode);
+
+	ret = ufshcd_dme_change_power_mode(hba, pwr_mode);
+
+	if (!ret)
+		ufshcd_vops_pwr_change_notify(hba, POST_CHANGE, pwr_mode);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(ufshcd_change_power_mode);
+
 /**
  * ufshcd_config_pwr_mode - configure a new power mode
  * @hba: per-adapter instance
@@ -4760,19 +4804,17 @@ int ufshcd_config_pwr_mode(struct ufs_hba *hba,
 	struct ufs_pa_layer_attr final_params = { 0 };
 	int ret;
 
-	ret = ufshcd_vops_pwr_change_notify(hba, PRE_CHANGE,
-					desired_pwr_mode, &final_params);
+	ret = ufshcd_vops_negotiate_pwr_mode(hba, desired_pwr_mode,
+					     &final_params);
+	if (ret) {
+		if (ret != -ENOTSUPP)
+			dev_err(hba->dev, "Failed to negotiate power mode: %d, use desired as is\n",
+				ret);
 
-	if (ret)
 		memcpy(&final_params, desired_pwr_mode, sizeof(final_params));
+	}
 
-	ret = ufshcd_change_power_mode(hba, &final_params);
-
-	if (!ret)
-		ufshcd_vops_pwr_change_notify(hba, POST_CHANGE, NULL,
-					&final_params);
-
-	return ret;
+	return ufshcd_change_power_mode(hba, &final_params);
 }
 EXPORT_SYMBOL_GPL(ufshcd_config_pwr_mode);
 
diff --git a/drivers/ufs/host/ufs-amd-versal2.c b/drivers/ufs/host/ufs-amd-versal2.c
index 40543db621a1..52031b7256fd 100644
--- a/drivers/ufs/host/ufs-amd-versal2.c
+++ b/drivers/ufs/host/ufs-amd-versal2.c
@@ -443,7 +443,6 @@ static int ufs_versal2_phy_ratesel(struct ufs_hba *hba, u32 activelanes, u32 rx_
 }
 
 static int ufs_versal2_pwr_change_notify(struct ufs_hba *hba, enum ufs_notify_change_status status,
-					 const struct ufs_pa_layer_attr *dev_max_params,
 					 struct ufs_pa_layer_attr *dev_req_params)
 {
 	struct ufs_versal2_host *host = ufshcd_get_variant(hba);
@@ -451,8 +450,6 @@ static int ufs_versal2_pwr_change_notify(struct ufs_hba *hba, enum ufs_notify_ch
 	int ret = 0;
 
 	if (status == PRE_CHANGE) {
-		memcpy(dev_req_params, dev_max_params, sizeof(struct ufs_pa_layer_attr));
-
 		/* If it is not a calibrated part, switch PWRMODE to SLOW_MODE */
 		if (!host->attcompval0 && !host->attcompval1 && !host->ctlecompval0 &&
 		    !host->ctlecompval1) {
diff --git a/drivers/ufs/host/ufs-exynos.c b/drivers/ufs/host/ufs-exynos.c
index 76fee3a79c77..77a6c8e44485 100644
--- a/drivers/ufs/host/ufs-exynos.c
+++ b/drivers/ufs/host/ufs-exynos.c
@@ -818,12 +818,10 @@ static u32 exynos_ufs_get_hs_gear(struct ufs_hba *hba)
 }
 
 static int exynos_ufs_pre_pwr_mode(struct ufs_hba *hba,
-				const struct ufs_pa_layer_attr *dev_max_params,
 				struct ufs_pa_layer_attr *dev_req_params)
 {
 	struct exynos_ufs *ufs = ufshcd_get_variant(hba);
 	struct phy *generic_phy = ufs->phy;
-	struct ufs_host_params host_params;
 	int ret;
 
 	if (!dev_req_params) {
@@ -832,18 +830,6 @@ static int exynos_ufs_pre_pwr_mode(struct ufs_hba *hba,
 		goto out;
 	}
 
-	ufshcd_init_host_params(&host_params);
-
-	/* This driver only support symmetric gear setting e.g. hs_tx_gear == hs_rx_gear */
-	host_params.hs_tx_gear = exynos_ufs_get_hs_gear(hba);
-	host_params.hs_rx_gear = exynos_ufs_get_hs_gear(hba);
-
-	ret = ufshcd_negotiate_pwr_params(&host_params, dev_max_params, dev_req_params);
-	if (ret) {
-		pr_err("%s: failed to determine capabilities\n", __func__);
-		goto out;
-	}
-
 	if (ufs->drv_data->pre_pwr_change)
 		ufs->drv_data->pre_pwr_change(ufs, dev_req_params);
 
@@ -1677,17 +1663,30 @@ static int exynos_ufs_link_startup_notify(struct ufs_hba *hba,
 	return ret;
 }
 
+static int exynos_ufs_negotiate_pwr_mode(struct ufs_hba *hba,
+					 const struct ufs_pa_layer_attr *dev_max_params,
+					 struct ufs_pa_layer_attr *dev_req_params)
+{
+	struct ufs_host_params host_params;
+
+	ufshcd_init_host_params(&host_params);
+
+	/* This driver only support symmetric gear setting e.g. hs_tx_gear == hs_rx_gear */
+	host_params.hs_tx_gear = exynos_ufs_get_hs_gear(hba);
+	host_params.hs_rx_gear = exynos_ufs_get_hs_gear(hba);
+
+	return ufshcd_negotiate_pwr_params(&host_params, dev_max_params, dev_req_params);
+}
+
 static int exynos_ufs_pwr_change_notify(struct ufs_hba *hba,
 				enum ufs_notify_change_status status,
-				const struct ufs_pa_layer_attr *dev_max_params,
 				struct ufs_pa_layer_attr *dev_req_params)
 {
 	int ret = 0;
 
 	switch (status) {
 	case PRE_CHANGE:
-		ret = exynos_ufs_pre_pwr_mode(hba, dev_max_params,
-					      dev_req_params);
+		ret = exynos_ufs_pre_pwr_mode(hba, dev_req_params);
 		break;
 	case POST_CHANGE:
 		ret = exynos_ufs_post_pwr_mode(hba, dev_req_params);
@@ -2015,6 +2014,7 @@ static const struct ufs_hba_variant_ops ufs_hba_exynos_ops = {
 	.exit				= exynos_ufs_exit,
 	.hce_enable_notify		= exynos_ufs_hce_enable_notify,
 	.link_startup_notify		= exynos_ufs_link_startup_notify,
+	.negotiate_pwr_mode		= exynos_ufs_negotiate_pwr_mode,
 	.pwr_change_notify		= exynos_ufs_pwr_change_notify,
 	.setup_clocks			= exynos_ufs_setup_clocks,
 	.setup_xfer_req			= exynos_ufs_specify_nexus_t_xfer_req,
diff --git a/drivers/ufs/host/ufs-hisi.c b/drivers/ufs/host/ufs-hisi.c
index 6f2e6bf31225..993e20ac211d 100644
--- a/drivers/ufs/host/ufs-hisi.c
+++ b/drivers/ufs/host/ufs-hisi.c
@@ -298,6 +298,17 @@ static void ufs_hisi_set_dev_cap(struct ufs_host_params *host_params)
 	ufshcd_init_host_params(host_params);
 }
 
+static int ufs_hisi_negotiate_pwr_mode(struct ufs_hba *hba,
+				       const struct ufs_pa_layer_attr *dev_max_params,
+				       struct ufs_pa_layer_attr *dev_req_params)
+{
+	struct ufs_host_params host_params;
+
+	ufs_hisi_set_dev_cap(&host_params);
+
+	return ufshcd_negotiate_pwr_params(&host_params, dev_max_params, dev_req_params);
+}
+
 static void ufs_hisi_pwr_change_pre_change(struct ufs_hba *hba)
 {
 	struct ufs_hisi_host *host = ufshcd_get_variant(hba);
@@ -362,10 +373,8 @@ static void ufs_hisi_pwr_change_pre_change(struct ufs_hba *hba)
 
 static int ufs_hisi_pwr_change_notify(struct ufs_hba *hba,
 				enum ufs_notify_change_status status,
-				const struct ufs_pa_layer_attr *dev_max_params,
 				struct ufs_pa_layer_attr *dev_req_params)
 {
-	struct ufs_host_params host_params;
 	int ret = 0;
 
 	if (!dev_req_params) {
@@ -377,14 +386,6 @@ static int ufs_hisi_pwr_change_notify(struct ufs_hba *hba,
 
 	switch (status) {
 	case PRE_CHANGE:
-		ufs_hisi_set_dev_cap(&host_params);
-		ret = ufshcd_negotiate_pwr_params(&host_params, dev_max_params, dev_req_params);
-		if (ret) {
-			dev_err(hba->dev,
-			    "%s: failed to determine capabilities\n", __func__);
-			goto out;
-		}
-
 		ufs_hisi_pwr_change_pre_change(hba);
 		break;
 	case POST_CHANGE:
@@ -543,6 +544,7 @@ static const struct ufs_hba_variant_ops ufs_hba_hi3660_vops = {
 	.name = "hi3660",
 	.init = ufs_hi3660_init,
 	.link_startup_notify = ufs_hisi_link_startup_notify,
+	.negotiate_pwr_mode = ufs_hisi_negotiate_pwr_mode,
 	.pwr_change_notify = ufs_hisi_pwr_change_notify,
 	.suspend = ufs_hisi_suspend,
 	.resume = ufs_hisi_resume,
@@ -552,6 +554,7 @@ static const struct ufs_hba_variant_ops ufs_hba_hi3670_vops = {
 	.name = "hi3670",
 	.init = ufs_hi3670_init,
 	.link_startup_notify = ufs_hisi_link_startup_notify,
+	.negotiate_pwr_mode = ufs_hisi_negotiate_pwr_mode,
 	.pwr_change_notify = ufs_hisi_pwr_change_notify,
 	.suspend = ufs_hisi_suspend,
 	.resume = ufs_hisi_resume,
diff --git a/drivers/ufs/host/ufs-mediatek.c b/drivers/ufs/host/ufs-mediatek.c
index 05892b9ac528..7b45cf0428af 100644
--- a/drivers/ufs/host/ufs-mediatek.c
+++ b/drivers/ufs/host/ufs-mediatek.c
@@ -1317,6 +1317,23 @@ static int ufs_mtk_init(struct ufs_hba *hba)
 	return err;
 }
 
+static int ufs_mtk_negotiate_pwr_mode(struct ufs_hba *hba,
+				      const struct ufs_pa_layer_attr *dev_max_params,
+				      struct ufs_pa_layer_attr *dev_req_params)
+{
+	struct ufs_host_params host_params;
+
+	ufshcd_init_host_params(&host_params);
+	host_params.hs_rx_gear = UFS_HS_G5;
+	host_params.hs_tx_gear = UFS_HS_G5;
+
+	if (dev_max_params->pwr_rx == SLOW_MODE ||
+	    dev_max_params->pwr_tx == SLOW_MODE)
+		host_params.desired_working_mode = UFS_PWM_MODE;
+
+	return ufshcd_negotiate_pwr_params(&host_params, dev_max_params, dev_req_params);
+}
+
 static bool ufs_mtk_pmc_via_fastauto(struct ufs_hba *hba,
 				     struct ufs_pa_layer_attr *dev_req_params)
 {
@@ -1372,26 +1389,10 @@ static void ufs_mtk_adjust_sync_length(struct ufs_hba *hba)
 }
 
 static int ufs_mtk_pre_pwr_change(struct ufs_hba *hba,
-				const struct ufs_pa_layer_attr *dev_max_params,
 				struct ufs_pa_layer_attr *dev_req_params)
 {
 	struct ufs_mtk_host *host = ufshcd_get_variant(hba);
-	struct ufs_host_params host_params;
-	int ret;
-
-	ufshcd_init_host_params(&host_params);
-	host_params.hs_rx_gear = UFS_HS_G5;
-	host_params.hs_tx_gear = UFS_HS_G5;
-
-	if (dev_max_params->pwr_rx == SLOW_MODE ||
-	    dev_max_params->pwr_tx == SLOW_MODE)
-		host_params.desired_working_mode = UFS_PWM_MODE;
-
-	ret = ufshcd_negotiate_pwr_params(&host_params, dev_max_params, dev_req_params);
-	if (ret) {
-		pr_info("%s: failed to determine capabilities\n",
-			__func__);
-	}
+	int ret = 0;
 
 	if (ufs_mtk_pmc_via_fastauto(hba, dev_req_params)) {
 		ufs_mtk_adjust_sync_length(hba);
@@ -1503,7 +1504,6 @@ static int ufs_mtk_auto_hibern8_disable(struct ufs_hba *hba)
 
 static int ufs_mtk_pwr_change_notify(struct ufs_hba *hba,
 				enum ufs_notify_change_status stage,
-				const struct ufs_pa_layer_attr *dev_max_params,
 				struct ufs_pa_layer_attr *dev_req_params)
 {
 	int ret = 0;
@@ -1515,8 +1515,7 @@ static int ufs_mtk_pwr_change_notify(struct ufs_hba *hba,
 			reg = ufshcd_readl(hba, REG_AUTO_HIBERNATE_IDLE_TIMER);
 			ufs_mtk_auto_hibern8_disable(hba);
 		}
-		ret = ufs_mtk_pre_pwr_change(hba, dev_max_params,
-					     dev_req_params);
+		ret = ufs_mtk_pre_pwr_change(hba, dev_req_params);
 		break;
 	case POST_CHANGE:
 		if (ufshcd_is_auto_hibern8_supported(hba))
@@ -2318,6 +2317,7 @@ static const struct ufs_hba_variant_ops ufs_hba_mtk_vops = {
 	.setup_clocks        = ufs_mtk_setup_clocks,
 	.hce_enable_notify   = ufs_mtk_hce_enable_notify,
 	.link_startup_notify = ufs_mtk_link_startup_notify,
+	.negotiate_pwr_mode  = ufs_mtk_negotiate_pwr_mode,
 	.pwr_change_notify   = ufs_mtk_pwr_change_notify,
 	.apply_dev_quirks    = ufs_mtk_apply_dev_quirks,
 	.fixup_dev_quirks    = ufs_mtk_fixup_dev_quirks,
diff --git a/drivers/ufs/host/ufs-qcom.c b/drivers/ufs/host/ufs-qcom.c
index 375fd24ba458..cdc769886e82 100644
--- a/drivers/ufs/host/ufs-qcom.c
+++ b/drivers/ufs/host/ufs-qcom.c
@@ -966,13 +966,21 @@ static void ufs_qcom_set_tx_hs_equalizer(struct ufs_hba *hba, u32 gear, u32 tx_l
 	}
 }
 
-static int ufs_qcom_pwr_change_notify(struct ufs_hba *hba,
-				enum ufs_notify_change_status status,
-				const struct ufs_pa_layer_attr *dev_max_params,
-				struct ufs_pa_layer_attr *dev_req_params)
+static int ufs_qcom_negotiate_pwr_mode(struct ufs_hba *hba,
+				       const struct ufs_pa_layer_attr *dev_max_params,
+				       struct ufs_pa_layer_attr *dev_req_params)
 {
 	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
 	struct ufs_host_params *host_params = &host->host_params;
+
+	return ufshcd_negotiate_pwr_params(host_params, dev_max_params, dev_req_params);
+}
+
+static int ufs_qcom_pwr_change_notify(struct ufs_hba *hba,
+				      enum ufs_notify_change_status status,
+				      struct ufs_pa_layer_attr *dev_req_params)
+{
+	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
 	int ret = 0;
 
 	if (!dev_req_params) {
@@ -982,13 +990,6 @@ static int ufs_qcom_pwr_change_notify(struct ufs_hba *hba,
 
 	switch (status) {
 	case PRE_CHANGE:
-		ret = ufshcd_negotiate_pwr_params(host_params, dev_max_params, dev_req_params);
-		if (ret) {
-			dev_err(hba->dev, "%s: failed to determine capabilities\n",
-					__func__);
-			return ret;
-		}
-
 		/*
 		 * During UFS driver probe, always update the PHY gear to match the negotiated
 		 * gear, so that, if quirk UFSHCD_QUIRK_REINIT_AFTER_MAX_GEAR_SWITCH is enabled,
@@ -2341,6 +2342,7 @@ static const struct ufs_hba_variant_ops ufs_hba_qcom_vops = {
 	.setup_clocks           = ufs_qcom_setup_clocks,
 	.hce_enable_notify      = ufs_qcom_hce_enable_notify,
 	.link_startup_notify    = ufs_qcom_link_startup_notify,
+	.negotiate_pwr_mode	= ufs_qcom_negotiate_pwr_mode,
 	.pwr_change_notify	= ufs_qcom_pwr_change_notify,
 	.apply_dev_quirks	= ufs_qcom_apply_dev_quirks,
 	.fixup_dev_quirks       = ufs_qcom_fixup_dev_quirks,
diff --git a/drivers/ufs/host/ufs-sprd.c b/drivers/ufs/host/ufs-sprd.c
index 65bd8fb96b99..a5e8c591bead 100644
--- a/drivers/ufs/host/ufs-sprd.c
+++ b/drivers/ufs/host/ufs-sprd.c
@@ -161,14 +161,11 @@ static int ufs_sprd_common_init(struct ufs_hba *hba)
 
 static int sprd_ufs_pwr_change_notify(struct ufs_hba *hba,
 				enum ufs_notify_change_status status,
-				const struct ufs_pa_layer_attr *dev_max_params,
 				struct ufs_pa_layer_attr *dev_req_params)
 {
 	struct ufs_sprd_host *host = ufshcd_get_variant(hba);
 
 	if (status == PRE_CHANGE) {
-		memcpy(dev_req_params, dev_max_params,
-			sizeof(struct ufs_pa_layer_attr));
 		if (host->unipro_ver >= UFS_UNIPRO_VER_1_8)
 			ufshcd_dme_configure_adapt(hba, dev_req_params->gear_tx,
 						   PA_INITIAL_ADAPT);
diff --git a/drivers/ufs/host/ufshcd-pci.c b/drivers/ufs/host/ufshcd-pci.c
index 5f65dfad1a71..8a4f2381a32e 100644
--- a/drivers/ufs/host/ufshcd-pci.c
+++ b/drivers/ufs/host/ufshcd-pci.c
@@ -145,7 +145,7 @@ static int ufs_intel_set_lanes(struct ufs_hba *hba, u32 lanes)
 
 	pwr_info.lane_rx = lanes;
 	pwr_info.lane_tx = lanes;
-	ret = ufshcd_config_pwr_mode(hba, &pwr_info);
+	ret = ufshcd_change_power_mode(hba, &pwr_info);
 	if (ret)
 		dev_err(hba->dev, "%s: Setting %u lanes, err = %d\n",
 			__func__, lanes, ret);
@@ -154,17 +154,15 @@ static int ufs_intel_set_lanes(struct ufs_hba *hba, u32 lanes)
 
 static int ufs_intel_lkf_pwr_change_notify(struct ufs_hba *hba,
 				enum ufs_notify_change_status status,
-				const struct ufs_pa_layer_attr *dev_max_params,
 				struct ufs_pa_layer_attr *dev_req_params)
 {
 	int err = 0;
 
 	switch (status) {
 	case PRE_CHANGE:
-		if (ufshcd_is_hs_mode(dev_max_params) &&
+		if (ufshcd_is_hs_mode(dev_req_params) &&
 		    (hba->pwr_info.lane_rx != 2 || hba->pwr_info.lane_tx != 2))
 			ufs_intel_set_lanes(hba, 2);
-		memcpy(dev_req_params, dev_max_params, sizeof(*dev_req_params));
 		break;
 	case POST_CHANGE:
 		if (ufshcd_is_hs_mode(dev_req_params)) {
diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h
index 8563b6648976..51c2555bea73 100644
--- a/include/ufs/ufshcd.h
+++ b/include/ufs/ufshcd.h
@@ -302,11 +302,10 @@ struct ufs_pwr_mode_info {
  *                     variant specific Uni-Pro initialization.
  * @link_startup_notify: called before and after Link startup is carried out
  *                       to allow variant specific Uni-Pro initialization.
+ * @negotiate_pwr_mode: called to negotiate power mode.
  * @pwr_change_notify: called before and after a power mode change
  *			is carried out to allow vendor spesific capabilities
- *			to be set. PRE_CHANGE can modify final_params based
- *			on desired_pwr_mode, but POST_CHANGE must not alter
- *			the final_params parameter
+ *			to be set.
  * @setup_xfer_req: called before any transfer request is issued
  *                  to set some things
  * @setup_task_mgmt: called before any task management request is issued
@@ -347,10 +346,12 @@ struct ufs_hba_variant_ops {
 				     enum ufs_notify_change_status);
 	int	(*link_startup_notify)(struct ufs_hba *,
 				       enum ufs_notify_change_status);
-	int	(*pwr_change_notify)(struct ufs_hba *,
-			enum ufs_notify_change_status status,
-			const struct ufs_pa_layer_attr *desired_pwr_mode,
-			struct ufs_pa_layer_attr *final_params);
+	int	(*negotiate_pwr_mode)(struct ufs_hba *hba,
+				      const struct ufs_pa_layer_attr *desired_pwr_mode,
+				      struct ufs_pa_layer_attr *final_params);
+	int	(*pwr_change_notify)(struct ufs_hba *hba,
+				     enum ufs_notify_change_status status,
+				     struct ufs_pa_layer_attr *final_params);
 	void	(*setup_xfer_req)(struct ufs_hba *hba, int tag,
 				  bool is_scsi_cmd);
 	void	(*setup_task_mgmt)(struct ufs_hba *, int, u8);
@@ -1361,6 +1362,8 @@ extern int ufshcd_dme_set_attr(struct ufs_hba *hba, u32 attr_sel,
 			       u8 attr_set, u32 mib_val, u8 peer);
 extern int ufshcd_dme_get_attr(struct ufs_hba *hba, u32 attr_sel,
 			       u32 *mib_val, u8 peer);
+extern int ufshcd_change_power_mode(struct ufs_hba *hba,
+				    struct ufs_pa_layer_attr *pwr_mode);
 extern int ufshcd_config_pwr_mode(struct ufs_hba *hba,
 			struct ufs_pa_layer_attr *desired_pwr_mode);
 extern int ufshcd_uic_change_pwr_mode(struct ufs_hba *hba, u8 mode);
-- 
2.34.1

Re: [PATCH v5 00/12] scsi: ufs: Add TX Equalization support for UFS 5.0

[Peter Wang (王信友)]

On Wed, 2026-03-25 at 08:21 -0700, Can Guo wrote:
> Hi,
> 
> The UFS v5.0 and UFSHCI v5.0 standards have published, introducing
> support
> for HS-G6 (46.6 Gbps per lane) through the new UniPro V3.0
> interconnect
> layer and M-PHY V6.0 physical layer specifications. To achieve
> reliable
> operation at these higher speeds, UniPro V3.0 introduces TX
> Equalization
> and Pre-Coding mechanisms that are essential for signal integrity.
> 
> This patch series implements TX Equalization support in the UFS core
> driver as specified in UFSHCI v5.0, along with the necessary vendor
> operations and a reference implementation for Qualcomm UFS host
> controllers.
> 

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

Re: [PATCH v5 00/12] scsi: ufs: Add TX Equalization support for UFS 5.0

[Martin K. Petersen]

Can,

> The UFS v5.0 and UFSHCI v5.0 standards have published, introducing
> support for HS-G6 (46.6 Gbps per lane) through the new UniPro V3.0
> interconnect layer and M-PHY V6.0 physical layer specifications. To
> achieve reliable operation at these higher speeds, UniPro V3.0
> introduces TX Equalization and Pre-Coding mechanisms that are
> essential for signal integrity.

Applied to 7.1/scsi-staging, thanks!

-- 
Martin K. Petersen

Re: [PATCH v5 00/12] scsi: ufs: Add TX Equalization support for UFS 5.0

[Martin K. Petersen]

On Wed, 25 Mar 2026 08:21:42 -0700, Can Guo wrote:

> The UFS v5.0 and UFSHCI v5.0 standards have published, introducing support
> for HS-G6 (46.6 Gbps per lane) through the new UniPro V3.0 interconnect
> layer and M-PHY V6.0 physical layer specifications. To achieve reliable
> operation at these higher speeds, UniPro V3.0 introduces TX Equalization
> and Pre-Coding mechanisms that are essential for signal integrity.
> 
> This patch series implements TX Equalization support in the UFS core
> driver as specified in UFSHCI v5.0, along with the necessary vendor
> operations and a reference implementation for Qualcomm UFS host
> controllers.
> 
> [...]

Applied to 7.1/scsi-queue, thanks!

[01/12] scsi: ufs: core: Introduce a new ufshcd vops negotiate_pwr_mode()
        https://git.kernel.org/mkp/scsi/c/d3eba21c7170
[02/12] scsi: ufs: core: Pass force_pmc to ufshcd_config_pwr_mode() as a parameter
        https://git.kernel.org/mkp/scsi/c/c91c83671642
[03/12] scsi: ufs: core: Add UFS_HS_G6 and UFS_HS_GEAR_MAX to enum ufs_hs_gear_tag
        https://git.kernel.org/mkp/scsi/c/6669ab18c223
[04/12] scsi: ufs: core: Add support for TX Equalization
        https://git.kernel.org/mkp/scsi/c/03e5d38e2f98
[05/12] scsi: ufs: core: Add debugfs entries for TX Equalization params
        https://git.kernel.org/mkp/scsi/c/10c40143f369
[06/12] scsi: ufs: core: Add helpers to pause and resume command processing
        https://git.kernel.org/mkp/scsi/c/dc5dcac53278
[07/12] scsi: ufs: core: Add support to retrain TX Equalization via debugfs
        https://git.kernel.org/mkp/scsi/c/adbabdcf0db0
[08/12] scsi: ufs: ufs-qcom: Fixup PAM-4 TX L0_L1_L2_L3 adaptation pattern length
        https://git.kernel.org/mkp/scsi/c/53c94067efa2
[09/12] scsi: ufs: ufs-qcom: Implement vops tx_eqtr_notify()
        https://git.kernel.org/mkp/scsi/c/385b95893e79
[10/12] scsi: ufs: ufs-qcom: Implement vops get_rx_fom()
        https://git.kernel.org/mkp/scsi/c/26605db7604d
[11/12] scsi: ufs: ufs-qcom: Implement vops apply_tx_eqtr_settings()
        https://git.kernel.org/mkp/scsi/c/16cbdc830877
[12/12] scsi: ufs: ufs-qcom: Enable TX Equalization
        https://git.kernel.org/mkp/scsi/c/57b7943fd87f

-- 
Martin K. Petersen