Re: [PATCH v3] [SCSI] mpt2sas, mpt3sas: Abort initialization if no memory I/O resources detected

[Timothy Pearson <tpearson@raptorengineeringinc.com>]

On 07/15/2015 01:28 PM, Yinghai Lu wrote:
> On Wed, Jul 15, 2015 at 6:52 AM, Timothy Pearson
> <tpearson@raptorengineeringinc.com> wrote:
>>> I have just kept the same description provide by Timothy in his
>>> initial patch.
>>>
>>> But I observe that their may be chance of getting "unable to handle
>>> kernel NULL pointer dereference" kernel panic if no Memory Resource
>>> available in the PCI subsystem. So agreed to the Timothy proposal of
>>> aborting the driver initialization if it doesn't detect any Memory
>>> resource instead of whole system get into panic state.
>>>
>> On some systems Linux is unable / unwilling to assign a BAR if the BIOS
>> does not assign one at startup.  I didn't look into the Linux allocator
>> side of things in much detail, but it is quite possible that Linux is
>> unaware the device only has partial resources assigned.
>>
> 
> Would be great if you can post boot log so we can figure about why those
> BARs are not assigned.
> 
> Yinghai

Unfortunately the systems exhibiting the issue were upgraded to a later
BIOS that does not have this problem; it might be possible to set up a
test system in the future but that probably won't happen for some time.

-- 
Timothy Pearson
Raptor Engineering
+1 (415) 727-8645
http://www.raptorengineeringinc.com