| Message ID | 20240627083756.25340-2-quic_rampraka@quicinc.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | Suspend clk scaling when there is no request | expand |
On 6/27/24 1:37 AM, Ram Prakash Gupta wrote: > diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c > index 1b65e6ae4137..9f935e5c60e8 100644 > --- a/drivers/ufs/core/ufshcd.c > +++ b/drivers/ufs/core/ufshcd.c > @@ -1560,7 +1560,8 @@ static int ufshcd_devfreq_target(struct device *dev, > ktime_to_us(ktime_sub(ktime_get(), start)), ret); > > out: > - if (sched_clk_scaling_suspend_work && !scale_up) > + if (sched_clk_scaling_suspend_work && > + (!scale_up || hba->clk_scaling.suspend_on_no_request)) > queue_work(hba->clk_scaling.workq, > &hba->clk_scaling.suspend_work); > > diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h > index bad88bd91995..c14607f2890b 100644 > --- a/include/ufs/ufshcd.h > +++ b/include/ufs/ufshcd.h > @@ -457,6 +457,7 @@ struct ufs_clk_scaling { > bool is_initialized; > bool is_busy_started; > bool is_suspended; > + bool suspend_on_no_request; > }; > > #define UFS_EVENT_HIST_LENGTH 8 Who are the other vendors that support clock scaling? I'm asking because I don't think that the behavior change introduced by this patch should depend on the SoC vendor. Thanks, Bart.
On 6/27/2024 10:05 PM, Bart Van Assche wrote: > On 6/27/24 1:37 AM, Ram Prakash Gupta wrote: >> diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c >> index 1b65e6ae4137..9f935e5c60e8 100644 >> --- a/drivers/ufs/core/ufshcd.c >> +++ b/drivers/ufs/core/ufshcd.c >> @@ -1560,7 +1560,8 @@ static int ufshcd_devfreq_target(struct device >> *dev, >> ktime_to_us(ktime_sub(ktime_get(), start)), ret); >> out: >> - if (sched_clk_scaling_suspend_work && !scale_up) >> + if (sched_clk_scaling_suspend_work && >> + (!scale_up || hba->clk_scaling.suspend_on_no_request)) >> queue_work(hba->clk_scaling.workq, >> &hba->clk_scaling.suspend_work); >> diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h >> index bad88bd91995..c14607f2890b 100644 >> --- a/include/ufs/ufshcd.h >> +++ b/include/ufs/ufshcd.h >> @@ -457,6 +457,7 @@ struct ufs_clk_scaling { >> bool is_initialized; >> bool is_busy_started; >> bool is_suspended; >> + bool suspend_on_no_request; >> }; >> #define UFS_EVENT_HIST_LENGTH 8 > > Who are the other vendors that support clock scaling? I'm asking because > I don't think that the behavior change introduced by this patch should > depend on the SoC vendor. > > Thanks, > > Bart. Hi Bart, I guess, Mediatek is one vendor who is having this feature in use as I see some fixes coming from Peter with respect to clk scaling, where some power regression on mediatek chipsets were addressed. Please check below link for background of this change and reason to keep it vendor specific. https://www.spinics.net/lists/linux-scsi/msg193591.html Thanks, Ram
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c index 1b65e6ae4137..9f935e5c60e8 100644 --- a/drivers/ufs/core/ufshcd.c +++ b/drivers/ufs/core/ufshcd.c @@ -1560,7 +1560,8 @@ static int ufshcd_devfreq_target(struct device *dev, ktime_to_us(ktime_sub(ktime_get(), start)), ret); out: - if (sched_clk_scaling_suspend_work && !scale_up) + if (sched_clk_scaling_suspend_work && + (!scale_up || hba->clk_scaling.suspend_on_no_request)) queue_work(hba->clk_scaling.workq, &hba->clk_scaling.suspend_work); diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h index bad88bd91995..c14607f2890b 100644 --- a/include/ufs/ufshcd.h +++ b/include/ufs/ufshcd.h @@ -457,6 +457,7 @@ struct ufs_clk_scaling { bool is_initialized; bool is_busy_started; bool is_suspended; + bool suspend_on_no_request; }; #define UFS_EVENT_HIST_LENGTH 8
Currently ufs clk scaling is getting suspended only when the clks are scaled down, but next when high load is generated its adding a huge amount of latency in scaling up the clk and complete the request post that. Now if the scaling is suspended in its existing state, and when high load is generated it is helping improve the random performance KPI by 28%. So suspending the scaling when there is no request. And the clk would be put in low scaled state when the actual request load is low. Making this change as optional for other vendor by having the check enabled using vops as for some vendor suspending without bringing the clk in low scaled state might have impact on power consumption on the SoC. Signed-off-by: Ram Prakash Gupta <quic_rampraka@quicinc.com> --- drivers/ufs/core/ufshcd.c | 3 ++- include/ufs/ufshcd.h | 1 + 2 files changed, 3 insertions(+), 1 deletion(-)