[arch-general] [radeonhd] [PATCH] PM patches: logic fix, feature, cleaning, memory downclocking

David C. Rankin, J.D.,P.E. drankinatty at suddenlinkmail.com
Fri May 29 01:26:45 EDT 2009

On or about Friday 29 May 2009 at approximately 00:01:26 Rafał Miłecki 
> 2009/5/29 David C. Rankin, J.D.,P.E. <drankinatty at suddenlinkmail.com>:
> > Rafał,
> >
> >        That's what I needed to know. I'm am not familiar with 'git' and
> > the
> >
> > git checkout -t -b downclocking origin/master
> > git am ~/archlinux/radeonhd/patches/*patch
> >
> > parts were the parts I knew nothing about. I'll pull the patches, apply
> > and report back. Something really has to give here. The heat is
> > unbearable. To get the actual temp data, I have a digital multimeter with
> > a great surface temperature probe on it ( Craftsman Model No. 82400 ) and
> > I took the temperature readings on the left palm rest and left fan
> > discharge of my laptop with the radeonhd driver active. The results:
> >
> > Left Palm Rest Temp: 96 Deg. F
> >
> > Left Fan Discharge: 147 Deg. F
> >
> >        The inside of this box is cooking.... That's with:
> >
> >  Option       "ForceLowPowerMode"
> >  Option       "LowPowerModeEngineClock" "140000"
> >
> >        I'll keep my fingers crossed and report back.
> Nice, tests with your multimeter would be absolutely great. You may
> also try to reduce EngineClock later. For example change it from
> 140000 to 120000. If it doesn't cause any corruptions you can still
> try decreasing that. Don't worry about values you may use 139999,
> 139998, 139997, end so on.AtomBIOS will round it to something
> acceptable.
> --
> Rafał Miłecki

Rafał, (also cc'ed to archlinux list for those interested)
	Here is a quick Summary of what I did:

23:54 alchemy:~/archlinux/apps/radeonhd> git checkout -t -b downclocking 
Branch downclocking set up to track remote branch master from origin.
Switched to a new branch 'downclocking'
23:55 alchemy:~/archlinux/apps/radeonhd> git am patches/*patch
Applying: PM: fix broken engine clock setting logic
/home/david/archlinux/apps/radeonhd/.git/rebase-apply/patch:30: trailing 
                           "calculated engine clock at %ldHz\n",
warning: 1 line adds whitespace errors.
Applying: PM: add RHDGetDefaultMemoryClock
Applying: PM: get rid of EnableForced field
Applying: PM: add memory downclocking. Commented out for now.
/home/david/archlinux/apps/radeonhd/.git/rebase-apply/patch:28: trailing 
                        "calculated memory clock at %ldHz\n",
warning: 1 line adds whitespace errors.

23:56 alchemy:~/archlinux/apps/radeonhd> find . -name 'rhd_pm.c'
23:57 alchemy:~/archlinux/apps/radeonhd> vi src/rhd_pm.c

        #if 1
        unsigned long defaultMemory = RHDGetDefaultMemoryClock(rhdPtr);
        if (defaultMemory) {
            Pm->ForcedMemoryClock = defaultMemory / 2;
            xf86DrvMsg(rhdPtr->scrnIndex, X_INFO, "ForceLowPowerMode: "
                        "calculated memory clock at %ldHz\n",

Reboot & check /var/log/Xorg.0.log
(II) RADEONHD: version 1.2.5, built from git branch downclocking, commit 
0de8b484 + changes

	The current log file is at:

	I haven't pulled any additional temperatures for comparison because there 
wouldn't be that much difference, it's still HOT. Looking through the log 
file, it is quite a coincidence that the downclocking chose 140000 as the 
memory clock downclock because that was exactly what I had been setting with 
	  Option       "LowPowerModeEngineClock" "140000"

	At least we know that the patch applies OK and that it has the desired effect 
on the memory clock. Now if we can just figure out what else we need to power 
down to get the temps under control, we will be home free!
	Thank you for your patch. As I said before, I have the perfect box for 
testing, so let me know when you have the next one ready and I'll be happy to 
test it.

David C. Rankin, J.D.,P.E.
Rankin Law Firm, PLLC
510 Ochiltree Street
Nacogdoches, Texas 75961
Telephone: (936) 715-9333
Facsimile: (936) 715-9339

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