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

Punit Agrawal
2021-06-11T14:39:23Z

Hi Heiko,

Heiko Stübner <heiko@sntech.de> writes:

> 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?

The device tree change is independent of the other patches in the
series. It would be great if you can pick this one - I am waiting on
feedback from Rob before sending an update on the remaining patches.

Thanks,
Punit

> 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>,
>>
>
>
>
>
>
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