From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johannes von Loewis Subject: Re: PST tables and Sonys Bios Date: Sun, 20 Jul 2003 18:58:09 +0200 Sender: cpufreq-admin@www.linux.org.uk Message-ID: <20030720165809.GA3019@zaphod.loewis.de> References: <3F1650C3.1030903@searchbroker.de> <1058458508.bd23a8ad4d31b@carlthompson.net> Reply-To: johannes@v.loewis.de Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: <1058458508.bd23a8ad4d31b@carlthompson.net> Errors-To: cpufreq-admin@www.linux.org.uk List-Unsubscribe: , List-Id: List-Post: List-Help: List-Subscribe: , List-Archive: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Cpufreq@www.linux.org.uk On Thu, Jul 17, 2003 at 09:15:08AM -0700, Carl Thompson wrote: > Fact 3: that BIOS update supposedly fixes several lockup problems due to > "system conflicts" according to the docs. > > Conclusion: my guess is that Sony purposely bumped up the voltage for _some_ > CPUs because they were having system stability problems related to voltage > scaling with them. It's possible that the PSTs are like this to actually > get your machine to run properly. > > You might want to consider that the PST as it is in the BIOS might be > required to keep your machine from locking up occasionally. Also rememeber My machine (Sony Vaio FX805, Linux 2.4.2[01]+acpi+swsusp+cpufreq) locks up occasionally. The BIOS PST is a "new one" with the voltage of 1.3V for all frequencies. I have not yet found out, what the reason(s) for the lock-ups is/are. Is it a problem with the standard kernel, a problem with one of the patches, or a problem with the softmodem driver hsflinmodem-5.03.whatever? Unfortunately, the BIOS PST is not sufficient to keep the machine from locking up;-) > that with those PSTs CPUFreq will still scale the CPU speed and save you > power, it just won't scale voltage too. Maybe getting the extra few > minutes of battery power that scaling the voltage might give you isn't > worth the hassle? On my laptop the effect of scaling only the frequency is not sufficient to keep the CPU fan from occasionally turning on. I have the hope to get the machine quiet (for low-load situations as text editing or mp3 playing) by scaling the voltage too. Therefore it seems desirable to me to have a means to override the BIOS PST in order to test upto what voltage the machine does not lock up much more often than with 1.3V. Regards Johannes