[PATCH v4 1/2] dt-bindings: ufs: Document static TX Equalization settings properties

[PATCH v4 1/2] dt-bindings: ufs: Document static TX Equalization settings properties

[Can Guo]

UFS v5.0/UFSHCI v5.0 add HS-G6 support (46.6 Gbps/lane) via UniPro v3.0
and M-PHY v6.0. In these specs, TX Equalization is defined for all High
Speed Gears (not only HS-G6) to compensate channel loss and improve signal
integrity at high speed operation.

For HS-G6, M-PHY uses PAM4 1b1b line coding, Pre-Coding may also be
required depending on channel characteristics.

Add vendor-neutral DT properties:

- patternProperties for txeq-preshoot-g[1-6] and txeq-deemphasis-g[1-6]
- fixed property tx-precode-enable-g6

Each property is a uint32 array of per-lane tuples:
<Host_Lane0 Device_Lane0>, [<Host_Lane1 Device_Lane1>]

Accept 2 or 4 values (x1/x2 lane configs). PreShoot and DeEmphasis values
are 0..7. Precode enable values are 0/1 and only applicable to HS-G6.

Acked-by: Manivannan Sadhasivam <mani@kernel.org>
Signed-off-by: Can Guo <can.guo@oss.qualcomm.com>
---
 .../devicetree/bindings/ufs/ufs-common.yaml   | 45 +++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/Documentation/devicetree/bindings/ufs/ufs-common.yaml b/Documentation/devicetree/bindings/ufs/ufs-common.yaml
index ed97f5682509..d90cf25adfa5 100644
--- a/Documentation/devicetree/bindings/ufs/ufs-common.yaml
+++ b/Documentation/devicetree/bindings/ufs/ufs-common.yaml
@@ -105,6 +105,51 @@ properties:
       Restricts the UFS controller to rate-a or rate-b for both TX and
       RX directions.
 
+  tx-precode-enable-g6:
+    $ref: /schemas/types.yaml#/definitions/uint32-array
+    oneOf:
+      - minItems: 2
+        maxItems: 2
+      - minItems: 4
+        maxItems: 4
+    items:
+      enum: [0, 1]
+    description: |
+      Static TX Precode enable values for HS-G6 only.
+      Values are specified as per-lane tuples:
+      <Host_Lane0 Device_Lane0>, [<Host_Lane1 Device_Lane1>].
+
+patternProperties:
+  "^txeq-preshoot-g[1-6]$":
+    $ref: /schemas/types.yaml#/definitions/uint32-array
+    oneOf:
+      - minItems: 2
+        maxItems: 2
+      - minItems: 4
+        maxItems: 4
+    items:
+      minimum: 0
+      maximum: 7
+    description: |
+      Static TX Equalization PreShoot values for High Speed Gears.
+      Values are specified as per-lane tuples:
+      <Host_Lane0 Device_Lane0>, [<Host_Lane1 Device_Lane1>].
+
+  "^txeq-deemphasis-g[1-6]$":
+    $ref: /schemas/types.yaml#/definitions/uint32-array
+    oneOf:
+      - minItems: 2
+        maxItems: 2
+      - minItems: 4
+        maxItems: 4
+    items:
+      minimum: 0
+      maximum: 7
+    description: |
+      Static TX Equalization DeEmphasis values for High Speed Gears.
+      Values are specified as per-lane tuples:
+      <Host_Lane0 Device_Lane0>, [<Host_Lane1 Device_Lane1>].
+
 dependencies:
   freq-table-hz: [ clocks ]
   operating-points-v2: [ clocks, clock-names ]
-- 
2.34.1

[PATCH v4 2/2] scsi: ufs: core: Add support for static TX Equalization settings

[Can Guo]

Static TX Equalization settings and TX Precode enable indication from DT
properties txeq-preshoot-g[1-6], txeq-deemphasis-g[1-6], and
tx-precode-enable-g6 are board-specific baseline values. Values are
provided as per-lane tuples:

<Host_Lane0 Device_Lane0>, [<Host_Lane1 Device_Lane1>]

Parse DT u32 properties with explicit range checks by using
of_property_count_u32_elems()/of_property_read_u32_array().

When adaptive TX Equalization is used, these static settings are not final:

- If valid settings are retrieved from qTxEQGnSettings/wTxEQGnSettingsExt,
  those retrieved settings override static DT settings.
- If retrieval is not available/valid, TX EQTR runs and trained settings
  override static DT settings.

So static DT settings are a fallback and are intended for cases where
adaptive TX Equalization is not enabled/used. Adaptive TX Equalization
remains the primary path when enabled.

No behavior changes for platforms that do not provide these properties.

Signed-off-by: Can Guo <can.guo@oss.qualcomm.com>
---
 drivers/ufs/core/ufs-txeq.c      |  10 ++-
 drivers/ufs/host/ufshcd-pltfrm.c | 126 +++++++++++++++++++++++++++++++
 include/ufs/ufshcd.h             |   2 +
 3 files changed, 137 insertions(+), 1 deletion(-)

diff --git a/drivers/ufs/core/ufs-txeq.c b/drivers/ufs/core/ufs-txeq.c
index 4b264adfdf49..b645fe5f6d95 100644
--- a/drivers/ufs/core/ufs-txeq.c
+++ b/drivers/ufs/core/ufs-txeq.c
@@ -1297,7 +1297,13 @@ int ufshcd_config_tx_eq_settings(struct ufs_hba *hba,
 	}
 
 	params = &hba->tx_eq_params[gear - 1];
-	if (!params->is_valid || force_tx_eqtr) {
+	/*
+	 * TX EQTR must run for the following cases:
+	 * 1. TX EQ settings are invalid.
+	 * 2. TX EQ settings are valid but static, i.e., populated from DT.
+	 * 3. TX EQTR procedure is forced.
+	 */
+	if (!params->is_valid || params->is_static || force_tx_eqtr) {
 		int ret;
 
 		ret = ufshcd_tx_eqtr(hba, params, pwr_mode);
@@ -1310,6 +1316,7 @@ 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_static = false;
 		params->is_applied = false;
 	}
 
@@ -1495,6 +1502,7 @@ static void ufshcd_extract_tx_eq_settings_attrs(struct ufs_hba *hba, u8 gear)
 	}
 
 	params->is_valid = true;
+	params->is_static = false;
 }
 
 void ufshcd_retrieve_tx_eq_settings(struct ufs_hba *hba)
diff --git a/drivers/ufs/host/ufshcd-pltfrm.c b/drivers/ufs/host/ufshcd-pltfrm.c
index c2dafb583cf5..6fe360efa80a 100644
--- a/drivers/ufs/host/ufshcd-pltfrm.c
+++ b/drivers/ufs/host/ufshcd-pltfrm.c
@@ -210,6 +210,130 @@ static void ufshcd_init_lanes_per_dir(struct ufs_hba *hba)
 	}
 }
 
+static void ufshcd_parse_static_tx_eq_settings(struct ufs_hba *hba)
+{
+	size_t sz = hba->lanes_per_direction * 2;
+	u32 lpd = hba->lanes_per_direction;
+	struct ufshcd_tx_eq_params *params;
+	u32 deemphasis[UFS_MAX_LANES * 2];
+	u32 precode_en[UFS_MAX_LANES * 2];
+	u32 preshoot[UFS_MAX_LANES * 2];
+	struct device *dev = hba->dev;
+	char prop_name[MAX_PROP_SIZE];
+	int i, err, count, gear, lane;
+
+	if (!lpd || lpd > UFS_MAX_LANES)
+		return;
+
+	for (gear = UFS_HS_G1; gear <= UFS_HS_GEAR_MAX; gear++) {
+		snprintf(prop_name, MAX_PROP_SIZE, "txeq-preshoot-g%d", gear);
+		count = of_property_count_u32_elems(dev->of_node, prop_name);
+		if (count <= 0)
+			continue;
+
+		if (count != sz) {
+			dev_err(dev, "Property %s has invalid count (%d), expecting %zu\n",
+				prop_name, count, sz);
+			continue;
+		}
+
+		err = of_property_read_u32_array(dev->of_node, prop_name, preshoot, sz);
+		if (err) {
+			dev_err(dev, "Failed to read %s property, %d\n",
+				prop_name, err);
+			continue;
+		}
+
+		for (i = 0; i < count; i++) {
+			if (preshoot[i] >= TX_HS_NUM_PRESHOOT) {
+				dev_err(dev, "An invalid TX EQ PreShoot (%d) provided in %s property\n",
+					preshoot[i], prop_name);
+				break;
+			}
+		}
+
+		if (i != count)
+			continue;
+
+		snprintf(prop_name, MAX_PROP_SIZE, "txeq-deemphasis-g%d", gear);
+		count = of_property_count_u32_elems(dev->of_node, prop_name);
+		if (count <= 0) {
+			dev_err(dev, "Missing required %s property\n", prop_name);
+			continue;
+		}
+
+		if (count != sz) {
+			dev_err(dev, "Property %s has invalid count (%d), expecting %zu\n",
+				prop_name, count, sz);
+			continue;
+		}
+
+		err = of_property_read_u32_array(dev->of_node, prop_name, deemphasis, sz);
+		if (err) {
+			dev_err(dev, "Failed to read %s property, %d\n",
+				prop_name, err);
+			continue;
+		}
+
+		for (i = 0; i < count; i++) {
+			if (deemphasis[i] >= TX_HS_NUM_DEEMPHASIS) {
+				dev_err(dev, "An invalid TX EQ DeEmphasis (%d) provided in %s property\n",
+					deemphasis[i], prop_name);
+				break;
+			}
+		}
+
+		if (i != count)
+			continue;
+
+		memset(precode_en, 0, sizeof(precode_en));
+		if (gear == UFS_HS_G6) {
+			snprintf(prop_name, MAX_PROP_SIZE, "tx-precode-enable-g%d", gear);
+			count = of_property_count_u32_elems(dev->of_node, prop_name);
+			if (count > 0) {
+				if (count != sz) {
+					dev_err(dev, "Property %s has invalid count (%d), expecting %zu\n",
+						prop_name, count, sz);
+					continue;
+				}
+
+				err = of_property_read_u32_array(dev->of_node, prop_name,
+								 precode_en, sz);
+				if (err) {
+					dev_err(dev, "Failed to read %s property, %d\n",
+						prop_name, err);
+					continue;
+				}
+
+				for (i = 0; i < count; i++) {
+					if (precode_en[i] > 1) {
+						dev_err(dev, "An invalid PrecodeEn (%d) provided in %s property\n",
+							precode_en[i], prop_name);
+						break;
+					}
+				}
+
+				if (i != count)
+					continue;
+			}
+		}
+
+		params = &hba->tx_eq_params[gear - 1];
+		for (lane = 0; lane < lpd; lane++) {
+			params->host[lane].preshoot = preshoot[lane * 2];
+			params->host[lane].deemphasis = deemphasis[lane * 2];
+			params->host[lane].precode_en = precode_en[lane * 2];
+
+			params->device[lane].preshoot = preshoot[lane * 2 + 1];
+			params->device[lane].deemphasis = deemphasis[lane * 2 + 1];
+			params->device[lane].precode_en = precode_en[lane * 2 + 1];
+		}
+
+		params->is_valid = true;
+		params->is_static = true;
+	}
+}
+
 /**
  * ufshcd_parse_clock_min_max_freq  - Parse MIN and MAX clocks freq
  * @hba: per adapter instance
@@ -528,6 +652,8 @@ int ufshcd_pltfrm_init(struct platform_device *pdev,
 
 	ufshcd_init_lanes_per_dir(hba);
 
+	ufshcd_parse_static_tx_eq_settings(hba);
+
 	err = ufshcd_parse_operating_points(hba);
 	if (err) {
 		dev_err(dev, "%s: OPP parse failed %d\n", __func__, err);
diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h
index f48d6416e299..c01824576472 100644
--- a/include/ufs/ufshcd.h
+++ b/include/ufs/ufshcd.h
@@ -359,6 +359,7 @@ struct ufshcd_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
+ * @is_static: True if settings are static
  */
 struct ufshcd_tx_eq_params {
 	struct ufshcd_tx_eq_settings host[UFS_MAX_LANES];
@@ -367,6 +368,7 @@ struct ufshcd_tx_eq_params {
 	bool is_valid;
 	bool is_applied;
 	bool is_trained;
+	bool is_static;
 };
 
 /**
-- 
2.34.1

Re: [PATCH v4 2/2] scsi: ufs: core: Add support for static TX Equalization settings

[Manivannan Sadhasivam]

On Thu, May 28, 2026 at 03:06:14AM -0700, Can Guo wrote:
> Static TX Equalization settings and TX Precode enable indication from DT
> properties txeq-preshoot-g[1-6], txeq-deemphasis-g[1-6], and
> tx-precode-enable-g6 are board-specific baseline values. Values are
> provided as per-lane tuples:
> 
> <Host_Lane0 Device_Lane0>, [<Host_Lane1 Device_Lane1>]
> 
> Parse DT u32 properties with explicit range checks by using
> of_property_count_u32_elems()/of_property_read_u32_array().
> 
> When adaptive TX Equalization is used, these static settings are not final:
> 
> - If valid settings are retrieved from qTxEQGnSettings/wTxEQGnSettingsExt,
>   those retrieved settings override static DT settings.
> - If retrieval is not available/valid, TX EQTR runs and trained settings
>   override static DT settings.
> 
> So static DT settings are a fallback and are intended for cases where
> adaptive TX Equalization is not enabled/used. Adaptive TX Equalization
> remains the primary path when enabled.
> 
> No behavior changes for platforms that do not provide these properties.
> 
> Signed-off-by: Can Guo <can.guo@oss.qualcomm.com>

Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>

- Mani

> ---
>  drivers/ufs/core/ufs-txeq.c      |  10 ++-
>  drivers/ufs/host/ufshcd-pltfrm.c | 126 +++++++++++++++++++++++++++++++
>  include/ufs/ufshcd.h             |   2 +
>  3 files changed, 137 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/ufs/core/ufs-txeq.c b/drivers/ufs/core/ufs-txeq.c
> index 4b264adfdf49..b645fe5f6d95 100644
> --- a/drivers/ufs/core/ufs-txeq.c
> +++ b/drivers/ufs/core/ufs-txeq.c
> @@ -1297,7 +1297,13 @@ int ufshcd_config_tx_eq_settings(struct ufs_hba *hba,
>  	}
>  
>  	params = &hba->tx_eq_params[gear - 1];
> -	if (!params->is_valid || force_tx_eqtr) {
> +	/*
> +	 * TX EQTR must run for the following cases:
> +	 * 1. TX EQ settings are invalid.
> +	 * 2. TX EQ settings are valid but static, i.e., populated from DT.
> +	 * 3. TX EQTR procedure is forced.
> +	 */
> +	if (!params->is_valid || params->is_static || force_tx_eqtr) {
>  		int ret;
>  
>  		ret = ufshcd_tx_eqtr(hba, params, pwr_mode);
> @@ -1310,6 +1316,7 @@ 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_static = false;
>  		params->is_applied = false;
>  	}
>  
> @@ -1495,6 +1502,7 @@ static void ufshcd_extract_tx_eq_settings_attrs(struct ufs_hba *hba, u8 gear)
>  	}
>  
>  	params->is_valid = true;
> +	params->is_static = false;
>  }
>  
>  void ufshcd_retrieve_tx_eq_settings(struct ufs_hba *hba)
> diff --git a/drivers/ufs/host/ufshcd-pltfrm.c b/drivers/ufs/host/ufshcd-pltfrm.c
> index c2dafb583cf5..6fe360efa80a 100644
> --- a/drivers/ufs/host/ufshcd-pltfrm.c
> +++ b/drivers/ufs/host/ufshcd-pltfrm.c
> @@ -210,6 +210,130 @@ static void ufshcd_init_lanes_per_dir(struct ufs_hba *hba)
>  	}
>  }
>  
> +static void ufshcd_parse_static_tx_eq_settings(struct ufs_hba *hba)
> +{
> +	size_t sz = hba->lanes_per_direction * 2;
> +	u32 lpd = hba->lanes_per_direction;
> +	struct ufshcd_tx_eq_params *params;
> +	u32 deemphasis[UFS_MAX_LANES * 2];
> +	u32 precode_en[UFS_MAX_LANES * 2];
> +	u32 preshoot[UFS_MAX_LANES * 2];
> +	struct device *dev = hba->dev;
> +	char prop_name[MAX_PROP_SIZE];
> +	int i, err, count, gear, lane;
> +
> +	if (!lpd || lpd > UFS_MAX_LANES)
> +		return;
> +
> +	for (gear = UFS_HS_G1; gear <= UFS_HS_GEAR_MAX; gear++) {
> +		snprintf(prop_name, MAX_PROP_SIZE, "txeq-preshoot-g%d", gear);
> +		count = of_property_count_u32_elems(dev->of_node, prop_name);
> +		if (count <= 0)
> +			continue;
> +
> +		if (count != sz) {
> +			dev_err(dev, "Property %s has invalid count (%d), expecting %zu\n",
> +				prop_name, count, sz);
> +			continue;
> +		}
> +
> +		err = of_property_read_u32_array(dev->of_node, prop_name, preshoot, sz);
> +		if (err) {
> +			dev_err(dev, "Failed to read %s property, %d\n",
> +				prop_name, err);
> +			continue;
> +		}
> +
> +		for (i = 0; i < count; i++) {
> +			if (preshoot[i] >= TX_HS_NUM_PRESHOOT) {
> +				dev_err(dev, "An invalid TX EQ PreShoot (%d) provided in %s property\n",
> +					preshoot[i], prop_name);
> +				break;
> +			}
> +		}
> +
> +		if (i != count)
> +			continue;
> +
> +		snprintf(prop_name, MAX_PROP_SIZE, "txeq-deemphasis-g%d", gear);
> +		count = of_property_count_u32_elems(dev->of_node, prop_name);
> +		if (count <= 0) {
> +			dev_err(dev, "Missing required %s property\n", prop_name);
> +			continue;
> +		}
> +
> +		if (count != sz) {
> +			dev_err(dev, "Property %s has invalid count (%d), expecting %zu\n",
> +				prop_name, count, sz);
> +			continue;
> +		}
> +
> +		err = of_property_read_u32_array(dev->of_node, prop_name, deemphasis, sz);
> +		if (err) {
> +			dev_err(dev, "Failed to read %s property, %d\n",
> +				prop_name, err);
> +			continue;
> +		}
> +
> +		for (i = 0; i < count; i++) {
> +			if (deemphasis[i] >= TX_HS_NUM_DEEMPHASIS) {
> +				dev_err(dev, "An invalid TX EQ DeEmphasis (%d) provided in %s property\n",
> +					deemphasis[i], prop_name);
> +				break;
> +			}
> +		}
> +
> +		if (i != count)
> +			continue;
> +
> +		memset(precode_en, 0, sizeof(precode_en));
> +		if (gear == UFS_HS_G6) {
> +			snprintf(prop_name, MAX_PROP_SIZE, "tx-precode-enable-g%d", gear);
> +			count = of_property_count_u32_elems(dev->of_node, prop_name);
> +			if (count > 0) {
> +				if (count != sz) {
> +					dev_err(dev, "Property %s has invalid count (%d), expecting %zu\n",
> +						prop_name, count, sz);
> +					continue;
> +				}
> +
> +				err = of_property_read_u32_array(dev->of_node, prop_name,
> +								 precode_en, sz);
> +				if (err) {
> +					dev_err(dev, "Failed to read %s property, %d\n",
> +						prop_name, err);
> +					continue;
> +				}
> +
> +				for (i = 0; i < count; i++) {
> +					if (precode_en[i] > 1) {
> +						dev_err(dev, "An invalid PrecodeEn (%d) provided in %s property\n",
> +							precode_en[i], prop_name);
> +						break;
> +					}
> +				}
> +
> +				if (i != count)
> +					continue;
> +			}
> +		}
> +
> +		params = &hba->tx_eq_params[gear - 1];
> +		for (lane = 0; lane < lpd; lane++) {
> +			params->host[lane].preshoot = preshoot[lane * 2];
> +			params->host[lane].deemphasis = deemphasis[lane * 2];
> +			params->host[lane].precode_en = precode_en[lane * 2];
> +
> +			params->device[lane].preshoot = preshoot[lane * 2 + 1];
> +			params->device[lane].deemphasis = deemphasis[lane * 2 + 1];
> +			params->device[lane].precode_en = precode_en[lane * 2 + 1];
> +		}
> +
> +		params->is_valid = true;
> +		params->is_static = true;
> +	}
> +}
> +
>  /**
>   * ufshcd_parse_clock_min_max_freq  - Parse MIN and MAX clocks freq
>   * @hba: per adapter instance
> @@ -528,6 +652,8 @@ int ufshcd_pltfrm_init(struct platform_device *pdev,
>  
>  	ufshcd_init_lanes_per_dir(hba);
>  
> +	ufshcd_parse_static_tx_eq_settings(hba);
> +
>  	err = ufshcd_parse_operating_points(hba);
>  	if (err) {
>  		dev_err(dev, "%s: OPP parse failed %d\n", __func__, err);
> diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h
> index f48d6416e299..c01824576472 100644
> --- a/include/ufs/ufshcd.h
> +++ b/include/ufs/ufshcd.h
> @@ -359,6 +359,7 @@ struct ufshcd_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
> + * @is_static: True if settings are static
>   */
>  struct ufshcd_tx_eq_params {
>  	struct ufshcd_tx_eq_settings host[UFS_MAX_LANES];
> @@ -367,6 +368,7 @@ struct ufshcd_tx_eq_params {
>  	bool is_valid;
>  	bool is_applied;
>  	bool is_trained;
> +	bool is_static;
>  };
>  
>  /**
> -- 
> 2.34.1
> 

-- 
மணிவண்ணன் சதாசிவம்

Re: [PATCH v4 1/2] dt-bindings: ufs: Document static TX Equalization settings properties

[Bean Huo]

On Thu, 2026-05-28 at 03:06 -0700, Can Guo wrote:
> UFS v5.0/UFSHCI v5.0 add HS-G6 support (46.6 Gbps/lane) via UniPro v3.0
> and M-PHY v6.0. In these specs, TX Equalization is defined for all High
> Speed Gears (not only HS-G6) to compensate channel loss and improve signal
> integrity at high speed operation.
> 
> For HS-G6, M-PHY uses PAM4 1b1b line coding, Pre-Coding may also be
> required depending on channel characteristics.
> 
> Add vendor-neutral DT properties:
> 
> - patternProperties for txeq-preshoot-g[1-6] and txeq-deemphasis-g[1-6]
> - fixed property tx-precode-enable-g6
> 
> Each property is a uint32 array of per-lane tuples:
> <Host_Lane0 Device_Lane0>, [<Host_Lane1 Device_Lane1>]
> 
> Accept 2 or 4 values (x1/x2 lane configs). PreShoot and DeEmphasis values
> are 0..7. Precode enable values are 0/1 and only applicable to HS-G6.
> 
> Acked-by: Manivannan Sadhasivam <mani@kernel.org>
> Signed-off-by: Can Guo <can.guo@oss.qualcomm.com>

Looks good to me!


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

Re: [PATCH v4 2/2] scsi: ufs: core: Add support for static TX Equalization settings

[Bart Van Assche]

On 5/28/26 3:06 AM, Can Guo wrote:
> +static void ufshcd_parse_static_tx_eq_settings(struct ufs_hba *hba)
> +{
> +	size_t sz = hba->lanes_per_direction * 2;

Please mark constants with "const". Additionally, is "sz" a good name
for this variable? The code below compares "count" and "sz". I haven't
seen it before that a count and a size are compared with each other.

Why "size_t" as data type? u32 should be sufficient, isn't it?

> +	u32 lpd = hba->lanes_per_direction;

Is this another constant?

> +	if (!lpd || lpd > UFS_MAX_LANES)
> +		return;

Should a kernel warning perhaps be issued if lpd > UFS_MAX_LANES?

> +	for (gear = UFS_HS_G1; gear <= UFS_HS_GEAR_MAX; gear++) {
> +		snprintf(prop_name, MAX_PROP_SIZE, "txeq-preshoot-g%d", gear);
> +		count = of_property_count_u32_elems(dev->of_node, prop_name);
> +		if (count <= 0)
> +			continue;

The body of this for-loop is long. Please consider moving the body of
this for-loop into a new function to reduce the indentation level of
the code.

> +		for (i = 0; i < count; i++) {
> +			if (preshoot[i] >= TX_HS_NUM_PRESHOOT) {
> +				dev_err(dev, "An invalid TX EQ PreShoot (%d) provided in %s property\n",
> +					preshoot[i], prop_name);
> +				break;
> +			}
> +		}
> +
> +		if (i != count)
> +			continue;

The traditional way in the Linux kernel for breaking out of a nested
loop is using a "goto" or "return" statement.

Thanks,

Bart.

Re: [PATCH v4 2/2] scsi: ufs: core: Add support for static TX Equalization settings

[Can Guo]

On 5/29/2026 12:02 AM, Bart Van Assche wrote:
> On 5/28/26 3:06 AM, Can Guo wrote:
>> +static void ufshcd_parse_static_tx_eq_settings(struct ufs_hba *hba)
>> +{
>> +    size_t sz = hba->lanes_per_direction * 2;
>
> Please mark constants with "const". Additionally, is "sz" a good name
> for this variable? The code below compares "count" and "sz". I haven't
> seen it before that a count and a size are compared with each other.
>
> Why "size_t" as data type? u32 should be sufficient, isn't it?
>
>> +    u32 lpd = hba->lanes_per_direction;
>
> Is this another constant?
>
>> +    if (!lpd || lpd > UFS_MAX_LANES)
>> +        return;
>
> Should a kernel warning perhaps be issued if lpd > UFS_MAX_LANES?
>
>> +    for (gear = UFS_HS_G1; gear <= UFS_HS_GEAR_MAX; gear++) {
>> +        snprintf(prop_name, MAX_PROP_SIZE, "txeq-preshoot-g%d", gear);
>> +        count = of_property_count_u32_elems(dev->of_node, prop_name);
>> +        if (count <= 0)
>> +            continue;
>
> The body of this for-loop is long. Please consider moving the body of
> this for-loop into a new function to reduce the indentation level of
> the code.
>
>> +        for (i = 0; i < count; i++) {
>> +            if (preshoot[i] >= TX_HS_NUM_PRESHOOT) {
>> +                dev_err(dev, "An invalid TX EQ PreShoot (%d) 
>> provided in %s property\n",
>> +                    preshoot[i], prop_name);
>> +                break;
>> +            }
>> +        }
>> +
>> +        if (i != count)
>> +            continue;
>
> The traditional way in the Linux kernel for breaking out of a nested
> loop is using a "goto" or "return" statement.
Hi Bart,

Thanks for the review, I will address them in next version.

Can Guo.
>
> Thanks,
>
> Bart.