Re: aic7xxx: aic7892(B): BUG: soft lockup detected on CPU#0!

[thomas schorpp <t.schorpp@gmx.de>]

James Bottomley wrote:
> On Sat, 2007-03-24 at 01:51 +0100, thomas schorpp wrote:
>>> no. so the pci layer reports wrong start:
>> nonsense. it succeeds, confused function return with the error flag:
>>
>> //      u_long  start;
>> //      u_long  start = 0xFFEFF000;
>>         u_long  start = 0x30000000;
>>         int     error;
>>
>>         struct resource* ret1;
>>         error = 0;
>> //      start = pci_resource_start(ahc->dev_softc, 1);
>>         if (start != 0) {
>>                 *bus_addr = start;
>>                 if ((ret1 = request_mem_region(start, 0x1000, "aic7xxx")) == 0)
> 
> You can't do this.  The pci_resource_start is getting the address of
> something called a Bus Address Register (BAR) it says in physical
> address space where the card is responding ... you can't simply set that
> to a random value.
> 
> The problem you seem to have is that your system is reporting a BAR
> beyond 32 bits (4GB) which the card physically can't use.  This could be
> because of a BIOS misconfiguration or because there's a bug in the PCI
> subsystem somewhere.
> 
> James

understood. waiting for LKML answers... meanwhile i found harder reason for 
a possible bounds problem with the driver code on x86_64:

if i do:

static int
ahc_linux_pci_reserve_mem_region(struct ahc_softc *ahc,
                                 u_long *bus_addr,
                                 uint8_t __iomem **maddr)
{
//      u_long  start;
        uint32_t start;

i get no free warning of "*nonexistant* resource" (it cant be nonexistant, 
cause it was definitely something mapped):

tom1:/usr/src/linux# dmesg |grep -i free
Freeing unused kernel memory: 208k freed

with u_long type start i get it:
Mar 24 03:41:47 localhost kernel: Trying to free nonexistent resource 
<00000000fffff000-00000000ffffffff>

investigating further...