[U-Boot-Users] U-Boot wrong cpu frequency calculation when setting PLPRCR directly

[U-Boot-Users] U-Boot wrong cpu frequency calculation when setting PLPRCR directly

[Antonio Di Bacco]

Hi all,

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.

Bye,
Antonio.

[U-Boot-Users] U-Boot wrong cpu frequency calculation when setting PLPRCR directly

[Markus Klotzbücher]

Dear Antonio,

Antonio Di Bacco <dibacco@libero.it> 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