• Status Closed
  • Percent Complete
  • Task Type Patches
  • Category Operating System/Drivers
  • Assigned To No-one
  • Operating System Another
  • Severity Low
  • Priority Very Low
  • Reported Version Daily build (which?)
  • Due in Version Undecided
  • Due Date Undecided
  • Votes
  • Private
Attached to Project: Rockbox
Opened by prof_wolfff - 2012-01-08
Last edited by saratoga - 2012-04-11

FS#12521 - iPod Classic/6G: cpu freq scaling

This patch implements HAVE_ADJUSTABLE_CPU_FREQ capability, CPU and bus frequency is divided by 2 and core voltage is decreased from 1.2 to 1.1V when unboosted.

Tthe previous ipod6g_holdswitch_poll patch must be applied before, otherwise the system is very unstable.

The task depends upon
ID Project Summary Priority Severity Assigned To Progress
12520 Rockbox  FS#12520 - iPod Classic/6G: holdswitch PMU polling crashes  Very Low Low
Closed by  saratoga
2012-04-11 01:59
Reason for closing:  Accepted
nls commented on 2012-01-09 19:47

Tested this together with  FS#12520  and it seems to be working fine on my 120GB classic

I am testing a more aggressive configuration: CPU: 54MHz, bus: 108MHz, Vcore: 1.050 V., it seems stable but need to test it a bit more, i will try to post it as soon as possible.

Works very well for me too, I’ve been using it for weeks on two Classics (80GB and 120GB). In addition to #12520, I have applied also #12523 and I get noticeably longer battery life while the player is very stable. Good job!

Thanks! v1 patch seems very stable, the new v2 patch i am posting sets CPU=54MHz, buses=54/54MHz (not sure, it could be 108/54) and Vcore=1.050V, it increases battery life about 15-20% (vs cpu-freq-v1 patch).

Battery life could be similar to OF when using this patch in conjunction with lcd_sleep-v2 patch (#12523), one tester reported battery bench lasted for 36h45m on a new 160Gb iPod, OF reached about 38 hours under similar conditions: one continuous run, autorepeat folder (70min. mp3@320), headphones inserted, volumen=-35dB, no EQ/effects, holdswitch on. I wonder if CPU voltage could be decreased one or two more steps…

pjdc commented on 2012-02-29 06:50

I’ve been running v2 of this patch (plus charger v1 and holdswitch-poll v1) for a day or so on my skinny 160GB, and the results are excellent so far.


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