CPU Scaling Fixes - Improve Battery Life Significantly - Page 3

mauro1 · 09:24 PM

@number1pete
I'm looking a bit into powersave_bias and I believe based on this post that what you're seeing is designed behavior resulting from not getting an even divisor between the available frequencies.

I'm going to test out these settings for a while and see how I make out.

Quote:

root@castle:/sys/devices/system/cpu/cpu0/cpufreq# grep . * ondemand/*
affected_cpus:0
cpuinfo_cur_freq:250000
cpuinfo_max_freq:600000
cpuinfo_min_freq:125000
scaling_available_frequencies:600000 550000 500000 250000 125000
scaling_available_governors:ondemand userspace
scaling_cur_freq:250000
scaling_driver:omap
scaling_governor:ondemand
scaling_max_freq:550000
scaling_min_freq:250000
ondemand/ignore_nice_load:0
ondemand/powersave_bias:50
ondemand/sampling_rate:1000000
ondemand/sampling_rate_max:100000000
ondemand/sampling_rate_min:100000
ondemand/up_threshold:11

So far I've played the built-in "have fun" video without any artifacts. This is based on about 15 minutes worth of testing while USB-attached (so I can see output through novacom). We'll see how it behaves with battery power. <crosses fingers>

Well *THAT* didn't work. I just found my phone "offline" after having been idle for 2 hours. The performance while I was using it was just fine. I fear I may have put the phone into too deep of a coma that it did not have enough juice to keep in sync with the Sprint tower by having increased the bias to 12%. WiFi works just fine in this status but the device just becomes the Palm PreTouch at this point, which is not entirely desirable.

Pulled the battery and the phone was restored (wonders of NOT putting experimental things in startup scripts).

number1pete · 08/02/2009, 09:29 AM

that powersave bias post you found is awesome thanks!

yeah i finaly got my first freeze. It happened to my phone while on the touchstone overnight and scaling b/t 125mhz and 550mhz.

also i did notice your code did not make since. acording to me your powersave bias should have been 500 not 50 to get it too 250mhz. You were probably sampling bugging.

I have found all the high higher frequencies (550 and 600mhz) to be fast but unreliable. Not sure why.

Will continue to test. at this point i am trying to find a stable scaling from 250mhz-500mhz for all those people who freeze at 125mhz.

number1pete · 08/02/2009, 09:39 AM

WOW, okay some dude was able to get some good info out of a palm rep. Apparently they saw our work here in the precentral forums and are rolling out official Palm supported cpu scaling. Nice work guys getting Palm off their booties and writing some good code to save our batteries.

Also if you care video recording will be available too. This major update is supposed to be rolled out in 40 days. I am just going to use my option #1 script till then because if palm wrote their own governor then no reason i need to be waisting my time.

scizzy · 08/02/2009, 10:31 AM

Quote:

Originally Posted by number1pete

WOW, okay some dude was able to get some good info out of a palm rep. Apparently they saw our work here in the precentral forums and are rolling out official Palm supported cpu scaling. Nice work guys getting Palm off their booties and writing some good code to save our batteries.

Also if you care video recording will be available too. This major update is supposed to be rolled out in 40 days. I am just going to use my option #1 script till then because if palm wrote their own governor then no reason i need to be waisting my time.

If youre right, I guess we'll see if whatever they do fixes my damn evdo problem... just out of curiosity, how did you get this info petey!?

number1pete · 08/02/2009, 12:59 PM

forgot to post the link.

palm leak

there are several threads now on precentral talking about it. But most people are just excited about video recording so look for posts for that.

Peteman100 · 08/02/2009, 07:25 PM

Wow if that is true, and Palm is going to natively support CPU scaling, that will be HUGE! Then again, its something they should have supported from the get-go, since the capability was always there.

number1pete · 08/03/2009, 07:16 AM

Oh the leak also talked about the 1500mAh battery palm is going to release. Forgot to mention that.

DNic · 08/03/2009, 08:12 AM

Quote:

Originally Posted by number1pete

Oh the leak also talked about the 1500mAh battery palm is going to release. Forgot to mention that.

Maybe Ill wait for that before getting the 1350/1400

Peteman100 · 08/03/2009, 07:06 PM

Quote:

Originally Posted by number1pete

Oh the leak also talked about the 1500mAh battery palm is going to release. Forgot to mention that.

Will it fit underneath the stock battery cover? Probably not, I am assuming...

VitViper · 08/04/2009, 10:00 AM

Quote:

Originally Posted by Peteman100

Will it fit underneath the stock battery cover? Probably not, I am assuming...

If Palm is releasing it, I'm sure it will.

number1pete · 08/04/2009, 10:01 AM

my guess is yes. Otherwise it would be a huge extended battery like 2600mAh.

lamboh · 08/07/2009, 02:48 AM

Quote:

Originally Posted by number1pete

my guess is yes. Otherwise it would be a huge extended battery like 2600mAh.

so you mind as well get the huge 3800 amzer...lol

number1pete · 08/07/2009, 08:26 AM

Okay it looks like my theory about the low frequency state receiving lower voltage is true.

I have been visiting with the guru's over at XDA forums and they confirmed that when using ondemand scaling when the frequency is lowered so is the voltage to the chip. This maybe why some of you freeze up at 125mhz because you have a bad chip and its not getting enough voltage to operate properly.

If we could get a fact sheet from TI for the OMAP then we would know the corresponding voltage decreases. Anyway this is probably why we see such improvements to battery life when scaling because the frequency is lowered as well as the voltage to the CPU.

here is the thread with our conversation.

on another note it looks bad for the rumor of the Pre having native support for scaling. If there are phones that lock up at 125mhz or 250mhz then there is nothing they can do for that with ondemand scaling since the cpu is what chooses the voltages not the software. But they may not utilize the ondemand governor. They may figure out a good way to use smart reflex or something. I will remain hopeful but now im scared.

Peteman100 · 08/07/2009, 12:08 PM

Quote:

Originally Posted by number1pete

on another note it looks bad for the rumor of the Pre having native support for scaling. If there are phones that lock up at 125mhz or 250mhz then there is nothing they can do for that with ondemand scaling since the cpu is what chooses the voltages not the software. But they may not utilize the ondemand governor. They may figure out a good way to use smart reflex or something. I will remain hopeful but now im scared.

Although I don't really know much about how scaling works, I can't imagine this is true. Why would TI build-in a hardware scaling scheme that their chips couldn't support? That would be ridiculously bad design, I can't imagine their engineers are that foolish. There must be something else to it.

number1pete · 08/13/2009, 02:07 PM

Quote:

Originally Posted by Peteman100

Although I don't really know much about how scaling works, I can't imagine this is true. Why would TI build-in a hardware scaling scheme that their chips couldn't support? That would be ridiculously bad design, I can't imagine their engineers are that foolish. There must be something else to it.

word on the street is that palm selected TI rejects to save money on the Pre. I dont beleive that however. I think the webos kernel and omap are not getting along for some reason. Palm will iorn this out.

Peteman100 · 08/13/2009, 02:52 PM

Quote:

Originally Posted by number1pete

word on the street is that palm selected TI rejects to save money on the Pre. I dont beleive that however. I think the webos kernel and omap are not getting along for some reason. Palm will iorn this out.

This thought crossed my mind but I can't believe it to be true. Both Palm and TI have too much reputation at stake for them to buy/sell (respectively) sub-functioning chips.

xcomputerman · 08:56 AM

Quote:

Originally Posted by number1pete

word on the street is that palm selected TI rejects to save money on the Pre. I dont beleive that however. I think the webos kernel and omap are not getting along for some reason. Palm will iorn this out.

As an embedded MCU production engineer, I have to say this is the most hilarious rumor I've ever seen on this board.

LOL.

number1pete · 08/21/2009, 08:59 AM

Quote:

Originally Posted by xcomputerman

As an embedded MCU production engineer, I have to say this is the most hilarious rumor I've ever seen on this board.

LOL.

Please explain why it is halrious. We do not know much about the chip fabrication process or the price of chips based on quality. I know server chips are cherry picked and cost more but that is about it. Please explain your case. Also what is MCU stand for?

08/02/2009, 09:29 AM	#42 (permalink)
number1pete Developer Join Date: Jul 2009 Location: Katy, Texas Posts: 584 Likes Received: 7 Thanks: 52 Thanked 287 Times in 93 Posts	that powersave bias post you found is awesome thanks! yeah i finaly got my first freeze. It happened to my phone while on the touchstone overnight and scaling b/t 125mhz and 550mhz. also i did notice your code did not make since. acording to me your powersave bias should have been 500 not 50 to get it too 250mhz. You were probably sampling bugging. I have found all the high higher frequencies (550 and 600mhz) to be fast but unreliable. Not sure why. Will continue to test. at this point i am trying to find a stable scaling from 250mhz-500mhz for all those people who freeze at 125mhz.
	Liked by

08/02/2009, 09:39 AM	#43 (permalink)
number1pete Developer Join Date: Jul 2009 Location: Katy, Texas Posts: 584 Likes Received: 7 Thanks: 52 Thanked 287 Times in 93 Posts	WOW, okay some dude was able to get some good info out of a palm rep. Apparently they saw our work here in the precentral forums and are rolling out official Palm supported cpu scaling. Nice work guys getting Palm off their booties and writing some good code to save our batteries. Also if you care video recording will be available too. This major update is supposed to be rolled out in 40 days. I am just going to use my option #1 script till then because if palm wrote their own governor then no reason i need to be waisting my time.
	Liked by

08/02/2009, 12:59 PM	#45 (permalink)
number1pete Developer Join Date: Jul 2009 Location: Katy, Texas Posts: 584 Likes Received: 7 Thanks: 52 Thanked 287 Times in 93 Posts	forgot to post the link. palm leak there are several threads now on precentral talking about it. But most people are just excited about video recording so look for posts for that.
	Liked by

08/02/2009, 07:25 PM	#46 (permalink)
Peteman100 Member Join Date: May 2009 Posts: 136 Likes Received: 0 Thanks: 6 Thanked 14 Times in 6 Posts	Wow if that is true, and Palm is going to natively support CPU scaling, that will be HUGE! Then again, its something they should have supported from the get-go, since the capability was always there.
	Liked by

08/03/2009, 07:16 AM	#47 (permalink)
number1pete Developer Join Date: Jul 2009 Location: Katy, Texas Posts: 584 Likes Received: 7 Thanks: 52 Thanked 287 Times in 93 Posts	Oh the leak also talked about the 1500mAh battery palm is going to release. Forgot to mention that.
	Liked by

08/04/2009, 10:01 AM	#51 (permalink)
number1pete Developer Join Date: Jul 2009 Location: Katy, Texas Posts: 584 Likes Received: 7 Thanks: 52 Thanked 287 Times in 93 Posts	my guess is yes. Otherwise it would be a huge extended battery like 2600mAh.
	Liked by

08/07/2009, 08:26 AM	#53 (permalink)
number1pete Developer Join Date: Jul 2009 Location: Katy, Texas Posts: 584 Likes Received: 7 Thanks: 52 Thanked 287 Times in 93 Posts	Okay it looks like my theory about the low frequency state receiving lower voltage is true. I have been visiting with the guru's over at XDA forums and they confirmed that when using ondemand scaling when the frequency is lowered so is the voltage to the chip. This maybe why some of you freeze up at 125mhz because you have a bad chip and its not getting enough voltage to operate properly. If we could get a fact sheet from TI for the OMAP then we would know the corresponding voltage decreases. Anyway this is probably why we see such improvements to battery life when scaling because the frequency is lowered as well as the voltage to the CPU. here is the thread with our conversation. on another note it looks bad for the rumor of the Pre having native support for scaling. If there are phones that lock up at 125mhz or 250mhz then there is nothing they can do for that with ondemand scaling since the cpu is what chooses the voltages not the software. But they may not utilize the ondemand governor. They may figure out a good way to use smart reflex or something. I will remain hopeful but now im scared.
	Liked by

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