Re: ipr boot failure caused by MSI (2.6.30-rc1+)

[Brian King <brking@linux.vnet.ibm.com>]

James Bottomley wrote:
> On Thu, 2009-05-21 at 14:51 -0500, James Bottomley wrote:
>> On Thu, 2009-05-21 at 13:47 -0500, Brian King wrote:
>>> cc'ing linuxppc-dev...
>>>
>>> -Brian
>>>
>>>
>>> James Bottomley wrote:
>>>> Kernels after 2.6.30-rc1 stopped booting on my powerstation.  The ipr
>>>> just times out and refuses to probe devices.  If I let it drop into the
>>>> initramfs system, this is what the interrupts shows:
>>>>
>>>> (initramfs) cat /proc/interrupts 
>>>>            CPU0       CPU1       CPU2       CPU3       
>>>>  16:         20         10         13         11   MPIC      Level     pata_amd
>>>>  20:          0          0          0          0   MPIC      Level     ohci_hcd:usb1, ohci_hcd:usb2
>>>>  21:          0          0          0          0  MPIC-U3MSI Edge      ipr
>>>>  68:         37         37         48         37   MPIC      Edge      serial
>>>> 251:         10         71         69         72   MPIC      Edge      ipi call function
>>>> 252:       1555       1779       1372       1155   MPIC      Edge      ipi reschedule
>>>> 253:          0          0          0          0   MPIC      Edge      ipi call function single
>>>> 254:          0          0          0          0   MPIC      Edge      ipi debugger
>>>> BAD:        416
>>>>
>>>> So you see the IPR is the only device not receiving them.
>>>>
>>>> I can fix the boot hang by reverting
>>>>
>>>> commit 5a9ef25b14d39b8413364df12cb8d9bb7a673a32
>>>> Author: Wayne Boyer <wayneb@linux.vnet.ibm.com>
>>>> Date:   Fri Jan 23 09:17:35 2009 -0800
>>>>
>>>>     [SCSI] ipr: add MSI support
>>>>
>>>> The system in question is:
>>>>
>>>> SYSTEM INFORMATION
>>>>  Processor  = PowerPC,970MP @ 2500 MHz
>>>>  I/O Bridge = U4 (4.4)
>>>>  SMP Size   = 4 (#0 #1 #2 #3)
>>>>  Boot-Date  = 2009-04-21 17:13:36
>>>>  Memory     = 2 GB of RAM @ 666 MHz
>>>>  Board Type = Bimini (7047191/0000000/1)
>>>>  MFG Date   = 1608
>>>>  Part No.   = 10N8748     
>>>>  FRU No.    = 10N7182     
>>>>  FRU Serial = YL30W8106038
>>>>  UUID       = 00000000000000000000000000000000
>>>>  Flashside  = 1 (temporary)
>>>>  Version    = HEAD
>>>>  Build Date = 12-04-2008 16:13
>> OK, so as an update, I booted to the initrd and inserted the network
>> modules, which are also MSI enabled and this is what I get:
>>
>> (initramfs) cat /proc/interrupts 
>>            CPU0       CPU1       CPU2       CPU3       
>>  16:         14         11         11         18   MPIC      Level     pata_amd
>>  20:          0          0          0          0   MPIC      Level     ohci_hcd:usb1, ohci_hcd:usb2
>>  21:          0          0          0          0  MPIC-U3MSI Edge      ipr
>>  22:          1          0          1          0  MPIC-U3MSI Edge      eth0
>>  23:          0          2          1          0  MPIC-U3MSI Edge      eth1
>>  68:        193        166        113        177   MPIC      Edge      serial
>> 251:         16         65         71         70   MPIC      Edge      ipi call function
>> 252:       1574       1804       1346       1289   MPIC      Edge      ipi reschedule
>> 253:          0          0          0          0   MPIC      Edge      ipi call function single
>> 254:          0          0          0          0   MPIC      Edge      ipi debugger
>> BAD:       1866
>>
>> So clearly the MSI interrupts to the network cards are working and it
>> looks like just a local problem with the ipr rather than a platform
>> problem with MSI.
> 
> I saw the quirk fix for this go by:
> 
> http://ozlabs.org/pipermail/linuxppc-dev/2009-May/072436.html
> 
> Is there an easy way to trigger an interrupt on this device?  Preferably
> in ipr_probe_ioa() so we can at least print out if the interrupts are
> misrouted and fall back from MSI to normal using the PCI infrastructure?

I just talked with one of the adapter firmware developers and it sounds like
this might be possible. I'll work with Wayne on coding something up to try.

-Brian

-- 
Brian King
Linux on Power Virtualization
IBM Linux Technology Center