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

[neil.armstrong@linaro.org]

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@linaro.org> # on SM8550-QRD
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8550-HDK
Tested-by: Neil Armstrong <neil.armstrong@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