The current configuration used for the IPQ5332 M31 USB PHY fails the
Near End High Speed Signal Quality compliance test. To resolve this,
update the initialization sequence as specified in the Hardware Design
Document.

Fixes: 08e49af50701 ("phy: qcom: Introduce M31 USB PHY driver")
Cc: stable@kernel.org
Signed-off-by: Kathiravan Thirumoorthy <kathiravan.thirumoorthy@oss.qualcomm.com>
---
 drivers/phy/qualcomm/phy-qcom-m31.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/phy/qualcomm/phy-qcom-m31.c b/drivers/phy/qualcomm/phy-qcom-m31.c
index 7caeea1b109e922c0cd12e985bc8868d5bce8b4f..1a8a0f1262cd95bc00dfbf7397a1c48d88d52327 100644
--- a/drivers/phy/qualcomm/phy-qcom-m31.c
+++ b/drivers/phy/qualcomm/phy-qcom-m31.c
@@ -58,12 +58,14 @@
  #define USB2_0_TX_ENABLE		BIT(2)
 
 #define USB2PHY_USB_PHY_M31_XCFGI_4	0xc8
- #define HSTX_SLEW_RATE_565PS		GENMASK(1, 0)
+ #define HSTX_SLEW_RATE_400PS		GENMASK(2, 0)
  #define PLL_CHARGING_PUMP_CURRENT_35UA	GENMASK(4, 3)
  #define ODT_VALUE_38_02_OHM		GENMASK(7, 6)
 
+#define USB2PHY_USB_PHY_M31_XCFGI_9	0xDC
+#define HSTX_CURRENT_17_1MA_385MV	BIT(1)
+
 #define USB2PHY_USB_PHY_M31_XCFGI_5	0xcc
- #define ODT_VALUE_45_02_OHM		BIT(2)
  #define HSTX_PRE_EMPHASIS_LEVEL_0_55MA	BIT(0)
 
 #define USB2PHY_USB_PHY_M31_XCFGI_11	0xe4
@@ -164,7 +166,7 @@ static struct m31_phy_regs m31_ipq5332_regs[] = {
 	},
 	{
 		USB2PHY_USB_PHY_M31_XCFGI_4,
-		HSTX_SLEW_RATE_565PS | PLL_CHARGING_PUMP_CURRENT_35UA | ODT_VALUE_38_02_OHM,
+		HSTX_SLEW_RATE_400PS | PLL_CHARGING_PUMP_CURRENT_35UA | ODT_VALUE_38_02_OHM,
 		0
 	},
 	{
@@ -174,9 +176,13 @@ static struct m31_phy_regs m31_ipq5332_regs[] = {
 	},
 	{
 		USB2PHY_USB_PHY_M31_XCFGI_5,
-		ODT_VALUE_45_02_OHM | HSTX_PRE_EMPHASIS_LEVEL_0_55MA,
+		HSTX_PRE_EMPHASIS_LEVEL_0_55MA,
 		4
 	},
+	{
+		USB2PHY_USB_PHY_M31_XCFGI_9,
+		HSTX_CURRENT_17_1MA_385MV,
+	},
 	{
 		USB_PHY_UTMI_CTRL5,
 		0x0,

---
base-commit: 2ae2aaafb21454f4781c30734959cf223ab486ef
change-id: 20250625-ipq5332_hsphy_complaince-c45be2e7224a

Best regards,
-- 
Kathiravan Thirumoorthy <kathiravan.thirumoorthy@oss.qualcomm.com>

On 6/25/25 9:00 AM, Kathiravan Thirumoorthy wrote:
> The current configuration used for the IPQ5332 M31 USB PHY fails the
> Near End High Speed Signal Quality compliance test. To resolve this,
> update the initialization sequence as specified in the Hardware Design
> Document.
> 
> Fixes: 08e49af50701 ("phy: qcom: Introduce M31 USB PHY driver")
> Cc: stable@kernel.org
> Signed-off-by: Kathiravan Thirumoorthy <kathiravan.thirumoorthy@oss.qualcomm.com>
> ---
>  drivers/phy/qualcomm/phy-qcom-m31.c | 14 ++++++++++----
>  1 file changed, 10 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/phy/qualcomm/phy-qcom-m31.c b/drivers/phy/qualcomm/phy-qcom-m31.c
> index 7caeea1b109e922c0cd12e985bc8868d5bce8b4f..1a8a0f1262cd95bc00dfbf7397a1c48d88d52327 100644
> --- a/drivers/phy/qualcomm/phy-qcom-m31.c
> +++ b/drivers/phy/qualcomm/phy-qcom-m31.c
> @@ -58,12 +58,14 @@
>   #define USB2_0_TX_ENABLE		BIT(2)
>  
>  #define USB2PHY_USB_PHY_M31_XCFGI_4	0xc8
> - #define HSTX_SLEW_RATE_565PS		GENMASK(1, 0)
> + #define HSTX_SLEW_RATE_400PS		GENMASK(2, 0)
>   #define PLL_CHARGING_PUMP_CURRENT_35UA	GENMASK(4, 3)
>   #define ODT_VALUE_38_02_OHM		GENMASK(7, 6)
>  
> +#define USB2PHY_USB_PHY_M31_XCFGI_9	0xDC

lowercase hex, please

also, please add it below XCFGI_5, so that it's sorted
both by name and by address

FWIW I can't find anything that would back up these changes, but
I trust what you're saying is true

Konrad

On 6/25/2025 7:28 PM, Konrad Dybcio wrote:
> On 6/25/25 9:00 AM, Kathiravan Thirumoorthy wrote:
>> The current configuration used for the IPQ5332 M31 USB PHY fails the
>> Near End High Speed Signal Quality compliance test. To resolve this,
>> update the initialization sequence as specified in the Hardware Design
>> Document.
>>
>> Fixes: 08e49af50701 ("phy: qcom: Introduce M31 USB PHY driver")
>> Cc: stable@kernel.org
>> Signed-off-by: Kathiravan Thirumoorthy <kathiravan.thirumoorthy@oss.qualcomm.com>
>> ---
>>   drivers/phy/qualcomm/phy-qcom-m31.c | 14 ++++++++++----
>>   1 file changed, 10 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/phy/qualcomm/phy-qcom-m31.c b/drivers/phy/qualcomm/phy-qcom-m31.c
>> index 7caeea1b109e922c0cd12e985bc8868d5bce8b4f..1a8a0f1262cd95bc00dfbf7397a1c48d88d52327 100644
>> --- a/drivers/phy/qualcomm/phy-qcom-m31.c
>> +++ b/drivers/phy/qualcomm/phy-qcom-m31.c
>> @@ -58,12 +58,14 @@
>>    #define USB2_0_TX_ENABLE		BIT(2)
>>   
>>   #define USB2PHY_USB_PHY_M31_XCFGI_4	0xc8
>> - #define HSTX_SLEW_RATE_565PS		GENMASK(1, 0)
>> + #define HSTX_SLEW_RATE_400PS		GENMASK(2, 0)
>>    #define PLL_CHARGING_PUMP_CURRENT_35UA	GENMASK(4, 3)
>>    #define ODT_VALUE_38_02_OHM		GENMASK(7, 6)
>>   
>> +#define USB2PHY_USB_PHY_M31_XCFGI_9	0xDC
> lowercase hex, please
>
> also, please add it below XCFGI_5, so that it's sorted
> both by name and by address

Ack. Will address this in V2.

>
> FWIW I can't find anything that would back up these changes, but
> I trust what you're saying is true

Thank You!. These changes are tested and confirmed by the relevant 
folks. I will try to find the doc and share it offline for reference.

>
> Konrad