[PATCH v3 0/8] Support Multi-frequency scale for UFS

[Ziqi Chen]

On 2/6/2025 5:53 PM, neil.armstrong at linaro.org wrote:
> On 03/02/2025 09:11, Ziqi Chen wrote:
>> With OPP V2 enabled, devfreq can scale clocks amongst multiple frequency
>> plans. However, the gear speed is only toggled between min and max during
>> clock scaling. Enable multi-level gear scaling by mapping clock 
>> frequencies
>> to gear speeds, so that when devfreq scales clock frequencies we can put
>> the UFS link at the appropraite gear speeds accordingly.
>>
>> This series has been tested on below platforms -
>> sm8550 mtp + UFS3.1
>> SM8650 MTP + UFS3.1
>> SM8750 MTP + UFS4.0
>>
>> v1 -> v2:
>> 1. Withdraw old patch 8/8 "ARM: dts: msm: Use Operation Points V2 for 
>> UFS on SM8650"
>> 2. Add new patch 8/8 "ABI: sysfs-driver-ufs: Add missing UFS sysfs 
>> addributes"
>> 3. Modify commit message for  "scsi: ufs: core: Pass target_freq to 
>> clk_scale_notify() vops" and "scsi: ufs: qcom: Pass target_freq to clk 
>> scale pre and post change"
>> 4. In "scsi: ufs: qcom: Pass target_freq to clk scale pre and post 
>> change", use common Macro HZ_PER_MHZ in function 
>> ufs_qcom_set_core_clk_ctrl()
>> 5. In "scsi: ufs: qcom: Implement the freq_to_gear_speed() vops", 
>> print out freq and gear info as debugging message
>> 6. In "scsi: ufs: core: Enable multi-level gear scaling", rename the 
>> lable "do_pmc" to "config_pwr_mode"
>> 7. In "scsi: ufs: core: Toggle Write Booster during clock", initialize 
>> the local variables "wb_en" as "false"
>>
>> v2 -> v3:
>> 1. Change 'vops' to 'vop' in all commit message
>> 2. keep the indentation consistent for clk_scale_notify() definition.
>> 3. In "scsi: ufs: core: Add a vop to map clock frequency to gear 
>> speed", "scsi: ufs: qcom: Implement the freq_to_gear_speed() vop"
>>     and "scsi: ufs: core: Enable multi-level gear scaling", remove the 
>> parameter 'gear' and use it as return result in function 
>> freq_to_gear_speed()
>> 4. In "scsi: ufs: qcom: Implement the freq_to_gear_speed(), removed 
>> the variable 'ret' in function ufs_qcom_freq_to_gear_speed()
>> 5. In "scsi: ufs: core: Enable multi-level gear scaling", use 
>> assignment instead memcpy() in function ufshcd_scale_gear()
>> 6. Improve the grammar of attributes' descriptions in “ABI: sysfs- 
>> driver-ufs: Add missing UFS sysfs attributes”
>> 7. Typo fixed for some commit messages.
>>
>> Can Guo (6):
>>    scsi: ufs: core: Pass target_freq to clk_scale_notify() vop
>>    scsi: ufs: qcom: Pass target_freq to clk scale pre and post change
>>    scsi: ufs: core: Add a vop to map clock frequency to gear speed
>>    scsi: ufs: qcom: Implement the freq_to_gear_speed() vop
>>    scsi: ufs: core: Enable multi-level gear scaling
>>    scsi: ufs: core: Toggle Write Booster during clock scaling base on
>>      gear speed
>>
>> Ziqi Chen (2):
>>    scsi: ufs: core: Check if scaling up is required when disable clkscale
>>    ABI: sysfs-driver-ufs: Add missing UFS sysfs attributes
>>
>>   Documentation/ABI/testing/sysfs-driver-ufs | 33 ++++++++++
>>   drivers/ufs/core/ufshcd-priv.h             | 15 ++++-
>>   drivers/ufs/core/ufshcd.c                  | 76 +++++++++++++++++-----
>>   drivers/ufs/host/ufs-mediatek.c            |  1 +
>>   drivers/ufs/host/ufs-qcom.c                | 62 ++++++++++++++----
>>   include/ufs/ufshcd.h                       |  9 ++-
>>   6 files changed, 160 insertions(+), 36 deletions(-)
>>
> 
> Tested-by: Neil Armstrong <neil.armstrong at linaro.org> # on SM8550-QRD
> Tested-by: Neil Armstrong <neil.armstrong at linaro.org> # on SM8550-HDK
> Tested-by: Neil Armstrong <neil.armstrong at linaro.org> # on SM8650-HDK
> 
> I added some traces and played with devfreq max_freq while copying data
> from the UFS disk, no issues observed.
> 
> Neil

Thank Neil for your test result.

-Ziqi