On Fri, Jun 4, 2010 at 10:41 AM, Stefan Reinauer <[email protected]> wrote: > On 6/4/10 6:36 PM, Myles Watson wrote: >> if (!(res->flags & IORESOURCE_FIXED)) >> continue; >> ... >> >> /* Is it already outside the limits? */ >> - if (((res->base + res->size -1) < lim->base) || (res->base > >> lim->limit)) >> + if (((res->base + res->size -1) < lim->base) || (res->base > >> lim->limit)) { >> + printk(BIOS_ERR, "%s: Resources not available.\n", >> dev_path(dev)); >> continue; >> + } >> >> This code only is executed for fixed resources. If they are outside >> of the limits it's a good thing. I don't think there should be an >> error message. >> > Why is that good? (can we add that explanation to the code as a comment?) Sure. I guess since I wrote it I'm not a good judge of clarifying comments.
Here's the big picture: You start with a full address space You constrain what the allocator can use by subtracting fixed resources And a completely contrived example: - take I/O 0x0000-0xffff - let's imagine that 0x400-420, 0x40-0x80, and 0xf000-0xf800 are fixed resources (the allocator can't use that space) First pass, the allocator chooses to use 0x420-0xffff (larger than 0x0-0x400) Second pass, the allocator does nothing because 0x40-0x80 is already outside the limits Third pass, the allocator chooses to use 0x420-0xf800 (larger than 0xf800-0xffff. I'd love it if you'd add some clarifying comments. Thanks, Myles -- coreboot mailing list: [email protected] http://www.coreboot.org/mailman/listinfo/coreboot
