[LinuxBIOS] [patch 4/4] AMD Geode GX/LX: CS5536 Southbridge

Corey Osgood corey_osgood at verizon.net
Wed May 2 02:57:28 CEST 2007


Uwe Hermann wrote:
> On Tue, May 01, 2007 at 04:48:31PM -0600, Marc Jones wrote:
>> Index: LinuxBIOSv2/src/southbridge/amd/cs5536/cs5536_smbus2.h
>> ===================================================================
>> --- LinuxBIOSv2.orig/src/southbridge/amd/cs5536/cs5536_smbus2.h	2007-04-30 15:14:24.000000000 -0600
>> +++ LinuxBIOSv2/src/southbridge/amd/cs5536/cs5536_smbus2.h	2007-04-30 15:14:24.000000000 -0600
> [...]
>>  static void smbus_delay(void)
>>  {
>> -	outb(0x80, 0x80);
>> +	inb(0x80);
>>  }
> 
> Why? Please document this in the code (what, how, why). Did you perform
> measurements? Why did the outb() not work?

There may be other reasons, but outb and inb both provide enough of a
delay for smbus use. By using inb, you don't clear a potentially helpful
post code.

>> Index: LinuxBIOSv2/src/mainboard/amd/norwich/auto.c
>> ===================================================================
>> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
>> +++ LinuxBIOSv2/src/mainboard/amd/norwich/auto.c	2007-05-01
01:32:02.000000000 -0600
> [...]
>> +#define POST_CODE(x) outb(x, 0x80)
>
> Why this? We have a post_code() function in src/console/console.c.
>

Isn't src/console/console.c for post ram init?

-Corey




More information about the coreboot mailing list