[PATCH v2] powerpc/powernv/pci-ioda: fix kdump with non-power-of-2 crashkernel=

Michael Ellerman mpe at ellerman.id.au
Mon Sep 7 19:19:09 AEST 2015

On Fri, 2015-09-04 at 11:22 -0700, Nishanth Aravamudan wrote:
> The 32-bit TCE table initialization relies on the DMA window having a
> size equal to a power of 2 (and checks for it explicitly). But
> crashkernel= has no constraint that requires a power-of-2 be specified.
> This causes the kdump kernel to fail to boot as none of the PCI devices
> (including the disk controller) are successfully initialized.
> After this change, the PCI devices successfully set up the 32-bit TCE
> table and kdump succeeds.
> Fixes: aca6913f5551 ("powerpc/powernv/ioda2: Introduce helpers to allocate TCE pages")
> Signed-off-by: Nishanth Aravamudan <nacc at linux.vnet.ibm.com>
> Cc: stable at vger.kernel.org # 4.2
> Michael, I kept this as a follow-on patch to my previous one. If you'd
> rather I made a v3 of that patch with the two fixes combined, I can
> resend.

No that's fine. I guess they could have been a single fix, but it's not a big deal.

> Also, I fixed up the context on my end to be u64, but not sure
> if that will match your tree (next doesn't have my prior patch applied
> yet, that I can see).

next isn't open yet, because we're still in the merge window, ie. rc1 hasn't
come out yet.

This is a fix so it'll go to my fixes branch. Whether I send that to Linus
before or after rc1 depends on how urgent the fixes people send me are. Sounds
like you'd like these two to go in asap?


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