Re: Crash while iterating over devices and resource

[Martin <dragonfly@xxxxxxxx>]

Matthew Dillon wrote:
> :Hi all,
> :
> :Since the old ndisulator code (which is in DragonFly) doesn't recognize 
> :my wireless card I've taken a shot at converting the current ndisulator 
> :code of FreeBSD to DragonFly.
> :
> :The code now correctly identifies my wireless card however the 
> :win-driver want to map io space. In the function where ndisulator does 
> :this it recursively iterate over all devices and resources to select the 
> :correct device to map to. The driver crashes in this code.
> :
> :Attached is a minimal example of the code which crashes (it crashes in 
> :the SLIST_FOREACH [macro]call) and a dump of the output just prior to 
> :crashing and after the crash.
> :
> :Since I don't now much about hardware I'm not sure whether it is normal 
> :that pci1 is a child of pci0, and I also would have thought the 
> :resource_list pointer of pci1 (which it crashes on) would be more in 
> :sequentual to the pointer of the resource_list pointers of agp0 and pcib1.
> :
> :Hope one of you can help.
> :
> :Martin
>
>     I think its a bug in pci_get_resource_list().
>
> struct resource_list *
> pci_get_resource_list (device_t dev, device_t child)
> {
>         struct pci_devinfo *    dinfo = device_get_ivars(child);
>         struct resource_list *  rl = &dinfo->resources;
>
>         if (!rl)
>                 return (NULL);
>
>         return (rl);
> }
>
>     That should probably be:
>
> struct resource_list *
> pci_get_resource_list (device_t dev, device_t child)
> {
>         struct pci_devinfo *dinfo = device_get_ivars(child);
>
>         if (dinfo == NULL)
>                 return (NULL);
>         return (&dinfo->resources);
> }
>
>
>     Try that and see what you get.
>
>     The PCI heirarchy is a real mess.  The busses can hang off of each
>     other, e.g. one pci bus can be a device on another pci bus.  It all
>     gets fed into the cpu somehow :-)
>
> 					-Matt

This fixed the issue! However the next one I got stuck on was the orm0. 
I fixed that by changing:

struct resource_list *
bus_generic_get_resource_list(device_t dev, device_t child)
{
	struct resource_list *rl;

	if (dev->parent)
		rl = BUS_GET_RESOURCE_LIST(dev->parent, child);
	else
		rl = NULL;
	return (rl);
}

to the FreeBSD version:

struct resource_list *
bus_generic_get_resource_list(device_t dev, device_t child)
{
	return (NULL);
}

I've no idea whether this correct.

After this one I got stuck on rl0. This one I simple passed by 
physically removing my network card ;) I need to figure out which part 
of the code is crashing in the rl-driver/resources so I can put this 
card back in, but first I want to make some progress with the ndisulator 
code.

Martin