[coreboot] Problem with the RTC

[Chris Lingard]

coreboot-v2 has been giving the following error:

PCI: 00:01.0 init
set power on after power fail
RTC Init
Invalid CMOS LB checksum
PNP: 002e.1 init

I have put some debugging in rtc_checksum_valid of mc146818rtc.c to 
output the variables, and got

PU model AMD Athlon(tm) 64 X2 Dual Core Processor 6000+
Setting up local apic... apic_id: 0x01 done.
CPU #1 Initialized
All AP CPUs stopped
PCI: 00:18.0 init
PCI: 00:01.0 init
set power on after power fail
RTC Init
Sum f31c
Old Sum f31c
Sum cfe1
Old Sum 2225
Invalid CMOS LB checksum
PNP: 002e.1 init

This persists on reboot, and on cold start. I have no idea why the 
second call to this procedure results in this, but think it is a timing 
problem.

This procedure is called twice from rtc_init, and I think that the 
second call is wrong; so I changed the second one:

         /* See if there is a LB CMOS checksum error */
         /*  checksum_invalid = !rtc_checksum_valid(LB_CKS_RANGE_START,
                         LB_CKS_RANGE_END,LB_CKS_LOC);  */
         if(checksum_invalid)
                 printk_debug("Invalid CMOS LB checksum\n");
                 {
                 /* Make certain we have a valid checksum */
                 rtc_set_checksum(PC_CKS_RANGE_START,
                         PC_CKS_RANGE_END,PC_CKS_LOC);
                 }

checksum_invalid is already set, so the second call to 
rtc_checksum_valid is commented out

The check sum was being written back every time, right or wrong, so I 
have put rtc_set_checksum within the failure bit.

Chris Lingard