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On Sun, Jan 11, 2004 at 12:56:10PM -0500, Mark W. Alexander wrote: > I'm not currently subscribed. Please cc: me on responses. > > I'm running 2.6.0 on an HP Pavilion ze4420 Athlon version (lspci -v below). I > recently flashed the BIOS (hoping against all odds for suspend to ram > capability) and the CPU frequencies discovered by PowerNOW (K7) has changed. > This is obviously caused by the BIOS update, but the stupid question of the day > is "Why?". If the CPU and chipset support both sets of frequencies with > different BIOS, wouldn't the _real_ set of supported frequencies be the union > of the 2? In reality, yes. However BIOS programmers have a different perception of reality to the rest of us. The spec for PST tables allows for up to 256 FID/VID pairs, yet everyone just seems to offer 5-6 as maximum. I guess they figured no-one needed the granularity of the full range. > As startling as it was to come up at 532Mhz the first boot, I can see where > this could provide some dramatic power savings (say, while using vi), > but the now missing 1064, 1463 and 1596 frequencies were more practical > for actually doing something worthwhile (say, using vi while watching a > DVD ;). > Is there anything I can do to persuade PowerNOW/frequency scaling to see the > full range of frequencies that I've seen this box can do? Something that has been planned for quite a while has been a means of overriding the tables using sysfs. I haven't had time to implement this, and no-one else has found the time/motivation to do so either it seems. Something I was tempted to do at one point (due to the number of broken PST's out there) was to offer a 'ignore_pst' module parameter, which exposed the full table to sysfs. The only problem being some VRMs can't handle certain frequencies at certain voltages whilst some can, making it hard to find a set of 'safe' values for each frequency. How to find out which one VRM can handle frequency X at voltage Y ? Through the PST tables. *sigh*, back to the drawing board. Dave - 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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