Re: cpufreq on TiBook 400 MHz

[Krisztian Mark Szentes <office@lsa.at>]

Hi Ben

Am Sonntag, 15. Juni 2003 15:52 schrieb Benjamin Herrenschmidt:
> On Thu, 2003-06-12 at 16:00, Krisztian Mark Szentes wrote:
> > On Friday 23 May 2003 00:48, Segher Boessenkool wrote:
> > > Krisztian Mark Szentes wrote:
> > > > I  wonder why there is no /proc/cpufreq on my Titanium PowerBook G4
> > > > (400 MHz).
> > > Because no-one filled in the right values yet.
> > ...
> > > I seem to remember the PowerBook3,2 @ 400 has a low speed of
> > > 300MHz, but I'm not fully sure about that -- better check it
> > > yourself (apple.com -> developer -> hardware -> all products
> > > or something like that, it's not too hard to find).
> > 
http://developer.apple.com/techpubs/hardware/Developer_Notes/Macintosh_CPUs-G4/PowerBook_G419Dec00/index.html
> > says:
> > "On the PowerBook G4 computer, the slower clock speed is 100 MHz slower 
> > than the rated speed: 300 MHz on a 400-MHz model, 400 MHz on a 500 MHz 
> > model."
> 
> Now, that's strange. I remember we measured 300Mhz for the low speed
> of the 500Mhz model... 

Am Freitag, 23. Mai 2003 11:19 schrieben Sie:

> I'm not sure that will work. On the other hand, I'm pretty sure the freq.
> switching is _NOT_ supported on this model...

finally I edited the sources (a version of 2.4.20 lying around here):
..
#define DEBUG_FREQ
..


       /* Else check for TiPb 500 */
        else if (machine_is_compatible("PowerBook3,2")) {
                /* Mark:and 400 MHz */
                if (cur_freq < 350000 || cur_freq > 550000)
                        goto out;
                hi_freq = cur_freq;
                low_freq = 300000;
                has_freq_ctl = 1;
                cpufreq_uses_pmu = 1;


recompiled and fired it up:
# cat /proc/cpuinfo
cpu             : 7410, altivec supported
temperature     : 17-21 C (uncalibrated)
clock           : 400MHz
revision        : 17.3 (pvr 800c 1103)
bogomips        : 797.90
machine         : PowerBook3,2
motherboard     : PowerBook3,2 MacRISC2 MacRISC Power Macintosh
detected as     : 71 (PowerBook Titanium)
pmac flags      : 0000000b
L2 cache        : 1024K unified
memory          : 512MB
pmac-generation : NewWorld
# cat /proc/sys/cpu/0/speed-min > /proc/sys/cpu/0/speed
# cat /proc/cpuinfo
cpu             : 7410, altivec supported
temperature     : 17-21 C (uncalibrated)
clock           : 300MHz
revision        : 17.3 (pvr 800c 1103)
bogomips        : 598.42
machine         : PowerBook3,2
motherboard     : PowerBook3,2 MacRISC2 MacRISC Power Macintosh
detected as     : 71 (PowerBook Titanium)
pmac flags      : 0000000b
L2 cache        : 1024K unified
memory          : 512MB
pmac-generation : NewWorld
# dmesg | tail -3
HID1, before: a0000000
HID1, after: 80000000
Calibrating delay loop... 598.01 BogoMIPS
# cat /proc/sys/cpu/0/speed-max > /proc/sys/cpu/0/speed
# cat /proc/cpuinfo
cpu             : 7410, altivec supported
temperature     : 18-22 C (uncalibrated)
clock           : 400MHz
revision        : 17.3 (pvr 800c 1103)
bogomips        : 797.90
machine         : PowerBook3,2
motherboard     : PowerBook3,2 MacRISC2 MacRISC Power Macintosh
detected as     : 71 (PowerBook Titanium)
pmac flags      : 0000000b
L2 cache        : 1024K unified
memory          : 512MB
pmac-generation : NewWorld
# dmesg | tail -3
HID1, before: 80000000
HID1, after: a0000000
Calibrating delay loop... 797.90 BogoMIPS


BTW, the power consumption as displayed by xpmumon changes only by approx. 
0,5 Watt. I also do not understand why the bogomips numbers are not 
exactly the same (598.01 versus 598.42).

Has it convinced you to include the Titanium 400 MHz into the future 
cpufreq supported models?

Thank you for your work!

Salut

Mark