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/
This archive was generated by hypermail 2b29 : Mon Jul 15 2002 - 22:00:27 EST