Re: Panic in a recent kernel (cardbus/pci related ?)

On Wednesday 30 December 2009 9:28:33 am John Baldwin wrote:
> On Friday 11 December 2009 12:15:27 am Thierry Herbelot wrote:
> > Hello,
> > 
> > I'm seeing a panic in my latest -Current kernel (config file == GENERIC 
> minus 
> > INVARIANTS, WITNESS and SMP). The machine is an older notebook, with a 
> PCMCIA 
> > network card.
> > 
> > The end of the verbose dmesg, showing the panic is following :
> > [SNIP]
> > Device configuration finished.
> > procfs registered
> > Timecounter "TSC" frequency 169163324 Hz quality 800
> > Timecounters tick every 1.000 msec
> > firewire0: fw_sidrcv: ERROR invalid self-id packet
> > firewire0: 1 nodes, maxhop <= 0 Not IRM capable irm(-1)
> > lo0: bpf attached
> > hptrr: no controller detected.
> > ata0: Identifying devices: 00000001
> > ata0: New devices: 00000001
> > usbus0: 12Mbps Full Speed USB v1.0
> > battery0: battery initialization start
> > battery1: battery initialization start
> > acpi_acad0: ugen0.1: <Intel> at usbus0
> > uhub0: <Intel UHCI root HUB, class 9/0, rev 1.00/1.00, addr 1> on usbus0
> > acline initialization start
> > acpi_acad0: On Line
> > acpi_acad0: acline initialization done, tried 1 times
> > ata0-master: pio=PIO4 wdma=WDMA2 udma=UDMA100 cable=80 wire
> > ad0: setting UDMA33
> > ad0: 28615MB <HITACHI DK23DA-30 00J1A0A1> at ata0-master UDMA33
> > ad0: 58605120 sectors [62016C/15H/63S] 16 sectors/interrupt 1 depth queue
> > unknown: Lazy allocation of 0x400 bytes rid 0x14 type 3 at 0x88000000
> > cbb1: Opening memory:
> > cbb1: Normal: 0x88000000-0x88000fff
> > cbb1: Opening memory:
> > cbb1: Normal: 0x88000000-0x88000fff
> >         map[10]: type I/O Port, range 32, base 0, size  8, port disabled
> >         map[14]: type Memory, range 32, base 0, size 10, enabled
> > panic: resource_list_add: resource entry is busy
> > KDB: enter: panic
> > [thread pid 8 tid 100032 ]
> > Stopped at      kdb_enter+0x3a: movl    $0,kdb_why
> > db> where
> > Tracing pid 8 tid 100032 td 0xc256cb40
> > kdb_enter(c0c9240f,c0c9240f,c0c93aaa,c23d4b70,c23d4b70,...) at 
> kdb_enter+0x3a
> > panic(c0c93aaa,3,14,400,ffffffff,...) at panic+0xd1
> > resource_list_add(c26e9004,3,14,0,ffffffff,...) at resource_list_add+0x96
> > pci_add_map(c26e9004,1,0,c23d4c58,14,...) at pci_add_map+0x628
> > pci_add_resources(c256b980,c267a980,1,0,1,...) at pci_add_resources+0x59e
> > cardbus_attach_card(c256b980,c24fd990,c0d23d08,f889cc55,ffebf3e8,...) at 
> > cardbus_attach_card+0x56e
> > cbb_event_thread(c2676000,c23d4d38,4478b00,840fc085,428,...) at 
> > cbb_event_thread+0x395
> > fork_exit(c070db40,c2676000,c23d4d38) at fork_exit+0x90
> > fork_trampoline() at fork_trampoline+0x8
> > --- trap 0, eip = 0, esp = 0xc23d4d70, ebp = 0 ---
> 
> I think I have finally figured this out.  What is happening is that the card 
> stores its CIS in a PCI BAR (this is probably fairly common for cardbus 
> cards).  So, the PCI BAR holding the CIS is being allocated before 
> pci_add_resources() is called hence the confusion.  There is a bit of a 
> chicken and egg problem here in that we need to parse the CIS to determine 
> what special requirements (e.g. prefetch) might be required for other BARs.  
> I'm not sure if the Cardbus spec makes certain guarantees about the properties 
> of a BAR that is used to hold the CIS.  I'm not actually sure how this worked 
> prior to my change as the resource for the CIS BAR should still have been 
> present in this case causing the same error (the old pci_release_resource() 
> would still have left the resource around).  I'll need to talk to Warner about 
> the best way to resolve this.

This is one possible hack.  It instructs the PCI bus to completely remove the
resource for the CIS.  While looking at this I found some other bugs (the code to
disable decoding in the ROM BAR didn't actually work for example) and have come up
with a larger patch.  It does a few things:

1) Fixes bus_generic_rl_(alloc|release)_resource() to not try to fetch a resource
list for a grandchildren.

2) Add full support for device ROM BARs to the PCI bus and remove the device ROM
hacks from the cardbus driver now that PCI manages them.

3) Use a resource_list_unreserve() when purging resources from a cardbus card when
it is removed as this is a bit cleaner.  Arguably the PCI bus driver should have a
'delete all resources' method that does this instead (hotplug PCI would need to
use it).

4) Remove unused pci_release_resource().

The patch is available at http://www.FreeBSD.org/~jhb/patches/cardbus.patch

-- 
John Baldwin