On Mon, 2025-02-10 at 18:02 +0800, Ziqi Chen wrote:
>
> External email : Please do not click links or open attachments until
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>
> From: Can Guo <quic_cang@xxxxxxxxxxx>
>
> 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 appropriate gear speeds accordingly.
>
> Signed-off-by: Can Guo <quic_cang@xxxxxxxxxxx>
> Co-developed-by: Ziqi Chen <quic_ziqichen@xxxxxxxxxxx>
> Signed-off-by: Ziqi Chen <quic_ziqichen@xxxxxxxxxxx>
> Reviewed-by: Bean Huo <beanhuo@xxxxxxxxxx>
> Reviewed-by: Bart Van Assche <bvanassche@xxxxxxx>
> Tested-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx>
> ---
>
> v1 -> v2:
> Rename the lable "do_pmc" to "config_pwr_mode".
>
> v2 -> v3:
> Use assignment instead memcpy() in function ufshcd_scale_gear().
>
> v3 -> v4:
> Typo fixed for commit message.
> ---
> drivers/ufs/core/ufshcd.c | 51 +++++++++++++++++++++++++++++++------
> --
> 1 file changed, 41 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
> index 8d295cc827cc..ebab897080a6 100644
> --- a/drivers/ufs/core/ufshcd.c
> +++ b/drivers/ufs/core/ufshcd.c
> @@ -1308,16 +1308,26 @@ static int
> ufshcd_wait_for_doorbell_clr(struct ufs_hba *hba,
> /**
> * ufshcd_scale_gear - scale up/down UFS gear
> * @hba: per adapter instance
> + * @target_gear: target gear to scale to
> * @scale_up: True for scaling up gear and false for scaling down
> *
> * Return: 0 for success; -EBUSY if scaling can't happen at this
> time;
> * non-zero for any other errors.
> */
> -static int ufshcd_scale_gear(struct ufs_hba *hba, bool scale_up)
> +static int ufshcd_scale_gear(struct ufs_hba *hba, u32 target_gear,
> bool scale_up)
> {
> int ret = 0;
> struct ufs_pa_layer_attr new_pwr_info;
>
> + if (target_gear) {
> + new_pwr_info = hba->pwr_info;
> + new_pwr_info.gear_tx = target_gear;
> + new_pwr_info.gear_rx = target_gear;
> +
> + goto config_pwr_mode;
> + }
> +
> + /* Legacy gear scaling, in case vops_freq_to_gear_speed() is
> not implemented */
> if (scale_up) {
> memcpy(&new_pwr_info, &hba-
> >clk_scaling.saved_pwr_info,
> sizeof(struct ufs_pa_layer_attr));
> @@ -1338,6 +1348,7 @@ static int ufshcd_scale_gear(struct ufs_hba
> *hba, bool scale_up)
> }
> }
>
> +config_pwr_mode:
> /* check if the power mode needs to be changed or not? */
> ret = ufshcd_config_pwr_mode(hba, &new_pwr_info);
> if (ret)
> @@ -1408,15 +1419,26 @@ static void
> ufshcd_clock_scaling_unprepare(struct ufs_hba *hba, int err, bool sc
> static int ufshcd_devfreq_scale(struct ufs_hba *hba, unsigned long
> freq,
> bool scale_up)
> {
> + u32 old_gear = hba->pwr_info.gear_rx;
> + int new_gear = 0;
> int ret = 0;
>
> + new_gear = ufshcd_vops_freq_to_gear_speed(hba, freq);
> + if (new_gear < 0)
> + /*
> + * return negative value means that the
> vops_freq_to_gear_speed() is not
> + * implemented or didn't find matched gear speed,
> assign '0' to new_gear
> + * to switch to legacy gear scaling sequence in
> ufshcd_scale_gear().
> + */
> + new_gear = 0;
> +
>
Hi Ziqi,
I think remove help function is better.
No need change new_gear type when use.
The readability is higher, and no need add that large amount comments.
u32_new_gear = 0;
if (hba->vops && hba->vops->freq_to_gear_speed)
new_gear = hba->vops->freq_to_gear_speed(hba, freq);
Thanks.
Peter
> ret = ufshcd_clock_scaling_prepare(hba, 1 * USEC_PER_SEC);
> if (ret)
> return ret;
>
> /* scale down the gear before scaling down clocks */
> if (!scale_up) {
> - ret = ufshcd_scale_gear(hba, false);
> + ret = ufshcd_scale_gear(hba, (u32)new_gear, false);
> if (ret)
> goto out_unprepare;
> }
> @@ -1424,13 +1446,13 @@ static int ufshcd_devfreq_scale(struct
> ufs_hba *hba, unsigned long freq,
> ret = ufshcd_scale_clks(hba, freq, scale_up);
> if (ret) {
> if (!scale_up)
> - ufshcd_scale_gear(hba, true);
> + ufshcd_scale_gear(hba, old_gear, true);
> goto out_unprepare;
> }
>
> /* scale up the gear after scaling up clocks */
> if (scale_up) {
> - ret = ufshcd_scale_gear(hba, true);
> + ret = ufshcd_scale_gear(hba, (u32)new_gear, true);
> if (ret) {
> ufshcd_scale_clks(hba, hba->devfreq-
> >previous_freq,
> false);
> @@ -1723,6 +1745,8 @@ static ssize_t
> ufshcd_clkscale_enable_store(struct device *dev,
> struct device_attribute *attr, const char *buf,
> size_t count)
> {
> struct ufs_hba *hba = dev_get_drvdata(dev);
> + struct ufs_clk_info *clki;
> + unsigned long freq;
> u32 value;
> int err = 0;
>
> @@ -1746,14 +1770,21 @@ static ssize_t
> ufshcd_clkscale_enable_store(struct device *dev,
>
> if (value) {
> ufshcd_resume_clkscaling(hba);
> - } else {
> - ufshcd_suspend_clkscaling(hba);
> - err = ufshcd_devfreq_scale(hba, ULONG_MAX, true);
> - if (err)
> - dev_err(hba->dev, "%s: failed to scale clocks
> up %d\n",
> - __func__, err);
> + goto out_rel;
> }
>
> + clki = list_first_entry(&hba->clk_list_head, struct
> ufs_clk_info, list);
> + freq = clki->max_freq;
> +
> + ufshcd_suspend_clkscaling(hba);
> + err = ufshcd_devfreq_scale(hba, freq, true);
> + if (err)
> + dev_err(hba->dev, "%s: failed to scale clocks up
> %d\n",
> + __func__, err);
> + else
> + hba->clk_scaling.target_freq = freq;
> +
> +out_rel:
> ufshcd_release(hba);
> ufshcd_rpm_put_sync(hba);
> out:
> --
> 2.34.1
>
