[PATCH V8 1/8] PM / devfreq: Add cpu based scaling support to passive_governor

[andrew-sh.cheng]

On Wed, 2021-05-26 at 12:08 +0900, Chanwoo Choi wrote:
> Hi,
> On 5/26/21 11:22 AM, andrew-sh.cheng wrote:
> > On Thu, 2021-04-08 at 11:47 +0900, Chanwoo Choi wrote:
> >> On 4/1/21 9:16 AM, Chanwoo Choi wrote:
> >>> On 3/31/21 10:03 PM, andrew-sh.cheng wrote:
> >>>> On Wed, 2021-03-31 at 17:35 +0900, Chanwoo Choi wrote:
> >>>>> On 3/31/21 5:27 PM, Chanwoo Choi wrote:
> >>>>>> Hi,
> >>>>>>
> >>>>>> On 3/31/21 5:03 PM, andrew-sh.cheng wrote:
> >>>>>>> On Thu, 2021-03-25 at 17:14 +0900, Chanwoo Choi wrote:
> >>>>>>>> Hi,
> >>>>>>>>
> >>>>>>>> You are missing to add these patches to linux-pm mailing list.
> >>>>>>>> Need to send them to linu-pm ML.
> >>>>>>>>
> >>>>>>>> Also, before received this series, I tried to clean-up these patches
> >>>>>>>> on testing branch[1]. So that I add my comment with my clean-up case.
> >>>>>>>> [1] https://urldefense.com/v3/__https://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/linux.git/log/?h=devfreq-testing-passive-gov__;!!CTRNKA9wMg0ARbw!zIrzeDp9vPnm1_SDzVPuzqdHn3zWie9DnfBXaA-j9-CSrVc6aR9_rJQQiw81_CgAPh9XRRs$ 
> >>>>>>>>
> >>>>>>>> And 'Saravana Kannan <skannan at codeaurora.org>' is wrong email address.
> >>>>>>>> Please update the email or drop this email.
> >>>>>>>
> >>>>>>> Hi Chanwoo,
> >>>>>>>
> >>>>>>> Thank you for the advices.
> >>>>>>> I will resend patch v9 (add to linux-pm ML), remove this patch, and note
> >>>>>>> that my patch set base on
> >>>>>>> https://urldefense.com/v3/__https://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/linux.git/log/?h=devfreq-testing-passive-gov__;!!CTRNKA9wMg0ARbw!yUlsuxrL5PcbF7o6A9DlCfvoA6w8V8VXKjYIybYyiJg3D0HM-lI2xRuxLUV6b3UJ8WFhg_g$ 
> >>>>>>
> >>>>>> I has not yet test this patch[1] on devfreq-testing-passive-gov branch.
> >>>>>> So that if possible, I'd like you to test your patches with this patch[1] 
> >>>>>> and then if there is no problem, could you send the next patches with patch[1]?
> >>>>>>
> >>>>>> [1]https://urldefense.com/v3/__https://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/linux.git/commit/?h=devfreq-testing-passive-gov&id=39c80d11a8f42dd63ecea1e0df595a0ceb83b454__;!!CTRNKA9wMg0ARbw!yUlsuxrL5PcbF7o6A9DlCfvoA6w8V8VXKjYIybYyiJg3D0HM-lI2xRuxLUV6b3UJR2cQqZs$ 
> >>>>>
> >>>>>
> >>>>> Sorry for the confusion. I make the devfreq-testing-passive-gov[1]
> >>>>> branch based on latest devfreq-next branch.
> >>>>> [1] https://urldefense.com/v3/__https://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/linux.git/log/?h=devfreq-testing-passive-gov__;!!CTRNKA9wMg0ARbw!yUlsuxrL5PcbF7o6A9DlCfvoA6w8V8VXKjYIybYyiJg3D0HM-lI2xRuxLUV6b3UJ8WFhg_g$ 
> >>>>>
> >>>>> First of all, if possible, I want to test them[1] with your patches in this series.
> >>>>> And then if there are no any problem, please let me know. After confirmed from you,
> >>>>> I'll send the patches of devfreq-testing-passive-gov[1] branch.
> >>>>> How about that?
> >>>>>
> >>>> Hi Chanwoo~
> >>>>
> >>>> We will use this on Google Chrome project.
> >>>> Google Hsin-Yi has test your patch + my patch set v8 [2~8]
> >>>>
> >>>>     make sure cci devfreqs runs with cpufreq.
> >>>>     suspend resume
> >>>>     speedometer2 benchmark
> >>>> It is okay.
> >>>>
> >>>> Please send the patches of devfreq-testing-passive-gov[1] branch.
> >>>>
> >>>> I will send patch v9 base on yours latter.
> >>>
> >>> Thanks for your test. I'll send the patches today.
> >>
> >> I'm sorry for delay because when I tested the patches
> >> for devfreq parent type on Odroid-xu3, there are some problem
> >> related to lazy linking of OPP. So I'm trying to analyze them.
> >> Unfortunately, we need to postpone these patches to next linux
> >> version.
> >>
> > Hi Chanwoo Choi~
> > 
> > It is said that you are busy on another task recently.
> > May I know your plan on this patch?
> > Thank you.
> 
> Sorry for late work. I have a question.
> When I tested exynos-bus.c with adding the 'required-opp' property
> on odroid-xu3 board. I got some fail about 
> 
> When calling _set_required_opps(), always _set_required_opp() returns
> -EBUSY error because of following lazy linking case[1].
> 
> [1] https://urldefense.com/v3/__https://elixir.bootlin.com/linux/v5.13-rc3/source/drivers/opp/core.c*L896__;Iw!!CTRNKA9wMg0ARbw!3eNxwDZRy-Ev5BHGxT-BxCz4qrNy0NZohQuBGW36krkwOkl_WX8yBmxlqSk9hxp_kxspMJI$ 
> 
> /* required-opps not fully initialized yet */
> if (lazy_linking_pending(opp_table))
> 	return -EBUSY;  
> 
> 
> For calling dev_pm_opp_of_add_table(), lazy_link_required_opp_table() function
> will be called. But, there is constraint[2]. If is_genpd of opp_table is false,
> driver/opp/of.c cannot resolve the lazy linking issue.
> 
> [2]  https://urldefense.com/v3/__https://elixir.bootlin.com/linux/v5.13-rc3/source/drivers/opp/of.c*L386__;Iw!!CTRNKA9wMg0ARbw!3eNxwDZRy-Ev5BHGxT-BxCz4qrNy0NZohQuBGW36krkwOkl_WX8yBmxlqSk9hxp_QFUVY9E$ 
> 
> /* Link required OPPs for all OPPs of the newly added OPP table */
> static void lazy_link_required_opp_table(struct opp_table *new_table)
> {
> 	struct opp_table *opp_table, *temp, **required_opp_tables;
> 	struct device_node *required_np, *opp_np, *required_table_np;
> 	struct dev_pm_opp *opp;
> 	int i, ret;
> 
> 	/*
> 	 * We only support genpd's OPPs in the "required-opps" for now,
> 	 * as we don't know much about other cases.
> 	 */
> 	if (!new_table->is_genpd)
> 		return;
> 
> Even if this case, there are no problem on your test case?
> 

Hi Chanwoo~
Sorry for late reply.
Yes, we meet similar issue.
Google member Hsin-Yi had helped deal with this issue on Chrome project.

Patch segment:
@ /drivers/opp/of.c

/* Link required OPPs for all OPPs of the newly added OPP table */
static void lazy_link_required_opp_table(struct opp_table *new_table)
{
	struct opp_table *opp_table, *temp, **required_opp_tables;
	struct device_node *required_np, *opp_np, *required_table_np;
	struct dev_pm_opp *opp;
	int i, ret;

+	/*
+	 * We only support genpd's OPPs in the "required-opps" for now,
+	 * as we don't know much about other cases.
+	 */
+	if (!new_table->is_genpd)
+		return;


Hsin-Yi replied this issue in the discussion list in the original lazy
link thread:
https://patchwork.kernel.org/project/linux-pm/patch/20190717222340.137578-4-saravanak@google.com/#23932203

Loop Hsin-YI here.
You can discuss with her if needing more detail.

Thank you both.