Re: [PATCH v3 4/4] arm64: dts: rockchip: Update PCI host bridge window to 32-bit address memory

Rob Herring
2021-06-15T21:29:27Z

On Thu, Jun 10, 2021 at 3:50 PM Heiko Stübner <heiko@sntech.de> wrote:
>
> Hi,
>
> Am Montag, 7. Juni 2021, 13:28:56 CEST schrieb Punit Agrawal:
> > The PCIe host bridge on RK3399 advertises a single 64-bit memory
> > address range even though it lies entirely below 4GB.
> >
> > Previously the OF PCI range parser treated 64-bit ranges more
> > leniently (i.e., as 32-bit), but since commit 9d57e61bf723 ("of/pci:
> > Add IORESOURCE_MEM_64 to resource flags for 64-bit memory addresses")
> > the code takes a stricter view and treats the ranges as advertised in
> > the device tree (i.e, as 64-bit).
> >
> > The change in behaviour causes failure when allocating bus addresses
> > to devices connected behind a PCI-to-PCI bridge that require
> > non-prefetchable memory ranges. The allocation failure was observed
> > for certain Samsung NVMe drives connected to RockPro64 boards.
> >
> > Update the host bridge window attributes to treat it as 32-bit address
> > memory. This fixes the allocation failure observed since commit
> > 9d57e61bf723.
> >
> > Reported-by: Alexandru Elisei <alexandru.elisei@arm.com>
> > Link: https://lore.kernel.org/r/7a1e2ebc-f7d8-8431-d844-41a9c36a8911@arm.com
> > Suggested-by: Robin Murphy <robin.murphy@arm.com>
> > Signed-off-by: Punit Agrawal <punitagrawal@gmail.com>
> > Tested-by: Alexandru Elisei <alexandru.elisei@arm.com>
> > Cc: Heiko Stuebner <heiko@sntech.de>
> > Cc: Rob Herring <robh+dt@kernel.org>
>
> just for clarity, should I just pick this patch separately for 5.13-rc to
> make it easy for people using current kernel devicetrees, or should
> this wait for the update mentioned in the cover-letter response
> and should go all together through the PCI tree?

This was dropped from v4, but should still be applied IMO.

Acked-by: Rob Herring <robh@kernel.org>