Re: [PATCH] phy: qcom: phy-qcom-m31: Update IPQ5332 M31 USB phy initialization sequence

[Kathiravan Thirumoorthy <kathiravan.thirumoorthy@oss.qualcomm.com>]

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