From mboxrd@z Thu Jan 1 00:00:00 1970 From: Markus =?iso-8859-1?Q?Klotzb=FCcher?= Date: Sat, 20 Jan 2007 18:03:44 +0100 Subject: [U-Boot-Users] U-Boot wrong cpu frequency calculation when setting PLPRCR directly In-Reply-To: (Antonio Di Bacco's message of "Sat, 20 Jan 2007 09:45:00 +0100") References: Message-ID: <873b65eikv.fsf@denx.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Dear Antonio, Antonio Di Bacco writes: > I setup the cpu frequency of a Freescale MPC880 directly providing a value > for the PLPRCR register. When the u-boot (1.2.0 and previous) starts, in > file speed.c it makes a calculation to display the CPU frequency based on > fields in PLPRCR. Working with integers it makes an approximation that > leads to a wrong cpu frequency in my case 130 Mhz instead of 132 Mhz). As a > consequence my clock was wrong gaining 20 minutes per day. It is easy to > patch the problem. If someone is interested I'll give him the patch. Please post the patch so at least it can be found in the archives later. Regards Markus Klotzbuecher