Re: [PATCH] arm64: defconfig: Change CONFIG_SM_TCSRCC_8750 from m to y

[Taniya Das <taniya.das@oss.qualcomm.com>]

On 10/17/2025 11:26 AM, Krzysztof Kozlowski wrote:
> On 17/10/2025 07:49, Taniya Das wrote:
>>
>>
>> On 10/17/2025 10:51 AM, Krzysztof Kozlowski wrote:
>>> On 17/10/2025 07:16, Taniya Das wrote:
>>>>
>>>>
>>>> On 10/17/2025 10:00 AM, Krzysztof Kozlowski wrote:
>>>>> On 16/10/2025 20:53, Taniya Das wrote:
>>>>>> The TCSR clock controller is required  during boot to provide the ref
>>>>>> clocks to the UFS controller. Setting CONFIG_SM_TCSRCC_8750 to y ensures
>>>>>> the UFS driver successfully probe and initialize the device.
>>>>>>
>>>>>> Without this change, the UFS subsystem fails to mount as a usable file
>>>>>> system during boot.
>>>>>
>>>>>
>>>>> That's not what I observed. UFS works fine, especially that it is a
>>>>> module, so no, this is not a desired change and explanation is not only
>>>>> insufficient but actually incorrect.
>>>>>
>>>>
>>>> Krzysztof, on Pakala MTP we are observing the below issue and it
>>>> requires the module of tscrcc to be loaded explicitly. This patch also
>>>> aligns to how it is on all other targets.
>>>>
>>>> /soc@0/phy@1d80000: Failed to get clk index: 2 ret: -517
>>>> [   10.496570] ufshcd-qcom 1d84000.ufs: freq-table-hz property not specified
>>>> [   10.503660] ufshcd-qcom 1d84000.ufs: ufshcd_populate_vreg: Unable to
>>>> find vdd-hba-supply regulator, assuming enabled
>>>> [   10.514548] ufshcd-qcom 1d84000.ufs: ufshcd_populate_vreg: Unable to
>>>> find vccq2-supply regulator, assuming enabled
>>>> [   10.565955] platform 1d80000.phy: deferred probe pending: (reason
>>>> unknown)
>>>> [   10.573078] platform 1d84000.ufs: deferred probe pending:
>>>> ufshcd-qcom: ufshcd_pltfrm_init() failed
>>>>
>>>
>>>
>>> I don't and I am testing regularly, so I assume you have incorrect
>>> config. Maybe I have incorrect one (which works), but then commit msg is
>>> incomplete - you must explain the bug and provide proof that this is the
>>> correct fix for it.
>>>
>>
>> We have tried booting up recently and and that is what we observed. The
>> patch from 'm' to 'y' helps the UFS probe is successful and the rootfs
>> is picked from ufs partitions. I will add these fail & success log
>> snippets in the commit text.
> 
> That's not enough. You need to explain why UFS fails. After explaining
> this, I guess bug in UFS would be exposed thus that one should be fixed.
> You just provided band-aid without fixing the real problem.
> 

When the kernel commandline uses is 'root=PARTLABEL=system', the  is a
dependency of the UFS driver on the TCSRCC clockref during bootup and
the TCSRCC made as a module will not provide the clocks unless we
explicitly load the modules. To meet this dependency we need to load
TCSRCC statically and move CONFIG_SM_TCSRCC_8750 from 'm' to 'y.
This will help the UFS partitions to be identified and then the rootfs
to be mounted from the partitions.

> NAK
> 
>>
>> [    0.000000] Machine model: Qualcomm Technologies, Inc. SM8750 MTP
>> ....
>> [    3.133373] ufshcd-qcom 1d84000.ufs: freq-table-hz property not specified
>> [    3.144480] ufshcd-qcom 1d84000.ufs: ufshcd_populate_vreg: Unable to
>> find vdd-hba-supply regulator, assuming enabled
>> [    3.144585] ufshcd-qcom 1d84000.ufs: ufshcd_populate_vreg: Unable to
>> find vccq2-supply regulator, assuming enabled
>> [    3.227770] ufshcd-qcom 1d84000.ufs: Resource ufs_mem not provided
>> [    3.238319] ufshcd-qcom 1d84000.ufs: MCQ mode is disabled, err=-19
> 
> 
> 
> Best regards,
> Krzysztof

-- 
Thanks,
Taniya Das