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

Heiko Stübner
2021-06-10T21:59:09Z

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?

If so, I can provide an
Acked-by: Heiko Stuebner <heiko@sntech.de>

> ---
> arch/arm64/boot/dts/rockchip/rk3399.dtsi | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/arm64/boot/dts/rockchip/rk3399.dtsi b/arch/arm64/boot/dts/rockchip/rk3399.dtsi
> index 634a91af8e83..4b854eb21f72 100644
> --- a/arch/arm64/boot/dts/rockchip/rk3399.dtsi
> +++ b/arch/arm64/boot/dts/rockchip/rk3399.dtsi
> @@ -227,7 +227,7 @@ pcie0: pcie@f8000000 {
> <&pcie_phy 2>, <&pcie_phy 3>;
> phy-names = "pcie-phy-0", "pcie-phy-1",
> "pcie-phy-2", "pcie-phy-3";
> - ranges = <0x83000000 0x0 0xfa000000 0x0 0xfa000000 0x0 0x1e00000>,
> + ranges = <0x82000000 0x0 0xfa000000 0x0 0xfa000000 0x0 0x1e00000>,
> <0x81000000 0x0 0xfbe00000 0x0 0xfbe00000 0x0 0x100000>;
> resets = <&cru SRST_PCIE_CORE>, <&cru SRST_PCIE_MGMT>,
> <&cru SRST_PCIE_MGMT_STICKY>, <&cru SRST_PCIE_PIPE>,