Messages in this thread | | | Subject | Re: Linux 2.4.19-rc1-ac3 | From | Peter Osterlund <> | Date | 14 Jul 2002 17:19:54 +0200 |
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Dominik Brodowski <devel@brodo.de> writes:
> On Sun, Jul 14, 2002 at 03:03:08PM +0200, Alan Cox wrote: > > > 3. The cpu voltage is automatically reduced when the frequency is > > > reduced. > > > > True for some x86 processors, either automatically, or on some > > controlled by us. > > The p4-clockmod driver you seem to using does not scale the voltage. > In case you own a P4-M and a ICH2-M or ICH3-M southbridge: the > speedstep.c driver in the 2.5.-cpufreq patchset (backport to 2.4. > will be available soon) should do the job and adjust the processor > voltage.
I tried speedstep but it didn't work because of this check in speedstep_detect_processor:
/* Intel Pentium 4 Mobile P4-M */ if (c->x86_model != 2) return 0;
if (c->x86_mask != 4) return 0; /* all those seem to support Enhanced SpeedStep */
My cpu has model == 1 and mask == 2. I deleted that code just to see what would happen, but then I tripped over this code in pentium4_get_frequency:
/* Don't trust unseen values yet, except in the MHz field */ if (msr_hi || ((msr_lo & 0x00FFFFFF) != 0x300511)) { printk(KERN_INFO "cpufreq: Due to incomplete documentation, please send a mail to devel@brodo.de\n"); printk(KERN_INFO "with a dmesg of a boot while on ac-power, and one of a boot on battery-power.\n"); printk(KERN_INFO "Thanks in advance.\n"); return 0; }
I removed the return statement, and then got:
apm: BIOS version 1.2 Flags 0x03 (Driver version 1.16) cpufreq: Intel(R) SpeedStep(TM) support $Revision: 1.34 $ model:1 mask:2 cpufreq: chipset 0x3 - processor 0x3 cpufreq: activating SpeedStep (TM) registers cpufreq: read at pmbase 0x1000 + 0x50 returned 0x1 cpufreq: P4 - MSR_EBC_FREQUENCY_ID: 0x8a01fe00 0x0 cpufreq: Due to incomplete documentation, please send a mail to devel@brodo.de with a dmesg of a boot while on ac-power, and one of a boot on battery-power. Thanks in advance. cpufreq: read at pmbase 0x1000 + 0x50 returned 0x1 cpufreq: writing 0x0 to pmbase 0x1000 + 0x50 cpufreq: read at pmbase 0x1000 + 0x50 returned 0x0 cpufreq: change to 0 MHz succeded cpufreq: read at pmbase 0x1000 + 0x50 returned 0x0 cpufreq: P4 - MSR_EBC_FREQUENCY_ID: 0x8a01fe00 0x0 cpufreq: Due to incomplete documentation, please send a mail to devel@brodo.de with a dmesg of a boot while on ac-power, and one of a boot on battery-power. Thanks in advance. cpufreq: read at pmbase 0x1000 + 0x50 returned 0x0 cpufreq: read at pmbase 0x1000 + 0x50 returned 0x0 cpufreq: currently at low speed setting - 13800 MHz CPU clock: 13800.000 MHz (13800.000-13800.000 MHz) Starting kswapd
There was no difference in dmesg output when booting on battery power instead of ac power.
So what can I do to make speedstep work? According to the notebook manual, speedstep is supported on this computer.
-- Peter Osterlund - petero2@telia.com http://w1.894.telia.com/~u89404340 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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