Re: [PATCH] arm64: defconfig: Enable Qualcomm UFS and QMP UFS PHY drivers as built-in

[Krzysztof Kozlowski <krzk@kernel.org>]

On 17/04/2026 12:37, Shawn Guo wrote:
> On Fri, Apr 17, 2026 at 10:44:20AM +0200, Krzysztof Kozlowski wrote:
>> On 17/04/2026 10:37, Shawn Guo wrote:
>>> On Fri, Apr 17, 2026 at 10:14:23AM +0200, Krzysztof Kozlowski wrote:
>>>> On 17/04/2026 05:55, Shawn Guo wrote:
>>>>> UFS is the primary storage for Linux rootfs across the breadth of
>>>>> Qualcomm development boards - Mobile, Automotive and IoT.  With
>>>>> Qualcomm UFS host controller driver (SCSI_UFS_QCOM) and the UFS PHY
>>>>> driver (PHY_QCOM_QMP_UFS) as modules, developers need an initramfs
>>>>
>>>> Yes, you always need initramfs and every developer has it.
>>>>
>>>>> to boot from UFS, which adds friction to daily development workflows.
>>>>
>>>> No friction, it's both standard, easy and all of Qualcomm and Linaro
>>>> developers have it solved long time ago.
>>>
>>> I'm looking at a kernel regression by running git bisect, where kernel
>>> version string varies for every single boot.  How do you usually deal
>>> with it by using initramfs?
>>
>> No difference from every other build and boot? I build kernel and the
>> same step I have initramfs with modules. Whether I bisect or build
>> kernel for normal boot is exactly the same.
>>
>> The only difference is `git bisect good`.
> 
> So we have to rebuild initramfs for every single bisect.  But isn't
> built-in make it easier and faster for the whole bisect process?

You rebuild initramfs anyway always but itself it is fast command. Your
change does not matter here - changed nothing. You anyway have to
rebuild it so the modules will be placed there.

> 
> It's especially useful for tasks where we do not even need to make modules,
> like debugging built-in drivers.

Nothing stops you from make it built-in, if you prefer. For me it is one
argument ("-S qcom") for my build script. Other has other ways (scripts
have even helper for that).

Best regards,
Krzysztof