Re: [BUG] 2.6.23-rc3-mm1 Kernel panic - not syncing: DMA: Memory would be corrupted

[Jeremy Higdon <jeremy@sgi.com>]

On Wed, Aug 22, 2007 at 05:05:54PM -0700, Luck, Tony wrote:
> > Hmm.  Must be something else going on then.  It should be less than 1MB
> > per ioc plus whatever is used for streaming I/O.
> >
> > | mptbase: Initiating ioc2 bringup                              | GSI 16 (level, low) -> CPU 2 (0xc418) vector 50
> > | ioc2: LSI53C1030 C0: Capabilities={Initiator}                 | ACPI: PCI Interrupt 0000:00:1d.0[A] -> GSI 16 (level, low) ->
> > | DMA: Out of SW-IOMMU space for 263200 bytes at device ?       | uhci_hcd 0000:00:1d.0: UHCI Host Controller
> > | Kernel panic - not syncing: DMA: Memory would be corrupted    | uhci_hcd 0000:00:1d.0: new USB bus registered, assigned bus n
> 
> I traced the pci_alloc_consistent calls from PrimeIocFifos on my
> system.  There are two calls for each ioc.  The first is for
> 266368 bytes, the second for 16320 bytes.
> 
> I wonder why Kamalesh's system wants the slightly different
> amount (263200 bytes) from what my system asks for?
> 
> It also looks to be a little unfriendly to swiotlb to ask for
> more than 256K at a time (see IO_TLB_SEGSIZE) in swiotlb.c
> 
> -Tony

I believe those would vary a bit based on the exact firmware
rev and perhaps nvram settings.  Also driver settings, but
those are presumably the same.

jeremy