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

[Krzysztof Kozlowski <krzk@kernel.org>]

On 17/10/2025 08:55, Taniya Das wrote:
> 
> 
> 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

No, that's not true. cmdline does not matter here at all.

> explicitly load the modules. To meet this dependency we need to load

root= has nothing to do with modules.

> TCSRCC statically and move CONFIG_SM_TCSRCC_8750 from 'm' to 'y.

No.

> This will help the UFS partitions to be identified and then the rootfs
> to be mounted from the partitions.

No, it's completely different problem. Now you are mixing UFS partitions
with root= argument.



Best regards,
Krzysztof