From mboxrd@z Thu Jan 1 00:00:00 1970 Message-Id: <200009211941.VAA05085@piglet.grunz.lu> Date: Thu, 21 Sep 2000 21:40:58 +0200 (CEST) From: Michel Lanners Reply-To: mlan@cpu.lu Subject: Re: CPU Temperature Patch To: trini@kernel.crashing.org cc: ad@mpifr-bonn.mpg.de, linuxppc-dev@lists.linuxppc.org In-Reply-To: <20000920110436.C15401@opus.bloom.county> MIME-Version: 1.0 Content-Type: TEXT/plain; charset=iso-8859-1 Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: Hi all, On 20 Sep, this message from Tom Rini echoed through cyberspace: > > On Wed, Sep 20, 2000 at 05:03:42PM +0200, Albrecht Dreß wrote: >> >> "D.J. Osguthorpe" wrote: >> > Here are two patches that appear to fix the cpu_temp function in setup.c. >> > They have been applied to a number of Ben Herrenschmidt kernels on a 500 MHz >> > Pismo powerbook and print reasonable values when you cat /proc/cpuinfo. >> >> The patch seems to work on my Lombard/333, too... Really great! >> >> > + /* this set for 500 MHz Pismo - how do we get access to clock?? */ >> >> There is, in the same file, around line 319 code to read the clock speed from >> the device tree. However, is it really necessary to include the clock speed at >> this point? What is the drawback if we just assume 500 MHz (or even the max >> value) for every G3 based machine? > > Why assume when we can do it properly? Besides, a friend of mine oc'ed his > B&W to 550, so it's possible to have >500Mhz :) To do it properly on all machines requires a processor frequency calculating routine, that doesn't depend on OF. Note that on all upgraded machines that did not initially have a G3, OF's value is wrong (too low, actually)! On the other hand, Motorola's doc states that setting too large a value doesn't hurt, so I guess we can safely hardcode something like 600 MHz. At the only expense of busy-waiting a bit too long on slower machines... but how often do you look at /proc/cpuinfo? Besides, you could always do the aproximation using the interrupt ;-) Michel ------------------------------------------------------------------------- Michel Lanners | " Read Philosophy. Study Art. 23, Rue Paul Henkes | Ask Questions. Make Mistakes. L-1710 Luxembourg | email mlan@cpu.lu | http://www.cpu.lu/~mlan | Learn Always. " ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/