Re: Regression: 2.6.34 boot fails on E5405 system, bisected: de08e2c26

["H. Peter Anvin" <hpa@zytor.com>]

So I suggest the following changes...

On 07/13/2010 07:19 PM, Jesse Barnes wrote:
>>
>> static int fixed_bar_cap(struct pci_bus *bus, unsigned int devfn)
>> {
>> 	int pos;
>> 	u32 pcie_cap = 0, cap_data;
>> 	printk("fixed_bar_cap, bus: %p  devfn: %u\n", bus, devfn);
>> 	pos = PCIE_CAP_OFFSET;
>> 	while (pos) {

while (pos >= PCIE_CAP_OFFSET) {

>> 		printk("Before read..\n");
>> 		if (raw_pci_ext_ops->read(pci_domain_nr(bus), bus->number,
>> 					  devfn, pos, 4, &pcie_cap))
>> 			return 0;
>> 		printk("pcie_cap: %u", pcie_cap);
>> 		
   -		if (pcie_cap == 0xffffffff)
   -			return 0;
		
   +		if (PCI_EXT_CAP_ID(pcie_cap) == 0x0000 ||
   +		    PCI_EXT_CAP_ID(pcie_cap) == 0xffff)
   +			break;
		
>> 		printk("Checking vendor..\n");

>> 		if (PCI_EXT_CAP_ID(pcie_cap) == PCI_EXT_CAP_ID_VNDR) {
>> 			printk("reading domain_nr\n");
>> 			raw_pci_ext_ops->read(pci_domain_nr(bus), bus->number,
>> 					      devfn, pos + 4, 4, &cap_data);
>> 			printk("cap_data: %u\n", cap_data);
>> 			if ((cap_data & 0xffff) == PCIE_VNDR_CAP_ID_FIXED_BAR)
>> 				return pos;
>> 		}
>>
>> 		pos = pcie_cap >> 20;

		pos = (pcie_cap >> 20) & 0xffc;

>> 		printk("pos after shift: %i\n", pos);
>> 	}
>>
>> 	printk("Returning from fixed_bar_cap\n");
>> 	return 0;
>> }
>>
>>
> 
> I thought a related bug was fixed already; the code should be returning
> all zeros for non-existent BAR reads.
>