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From:   Punit Agrawal <punitagrawal@gmail.com>
To:     linux-rockchip@lists.infradead.org, linux-pci@vger.kernel.org
Cc:     Punit Agrawal <punitagrawal@gmail.com>,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        alexandru.elisei@arm.com, wqu@suse.com, robin.murphy@arm.com,
        pgwipeout@gmail.com, ardb@kernel.org, briannorris@chromium.org,
        shawn.lin@rock-chips.com, helgaas@kernel.org, robh+dt@kernel.org,
        Heiko Stuebner <heiko@sntech.de>
Subject: [PATCH 2/2] arm64: dts: rockchip: Update PCI host bridge window to 32-bit address memory
Date:   Fri, 28 May 2021 00:05:42 +0900
Message-Id: <20210527150541.3130505-3-punitagrawal@gmail.com>
In-Reply-To: <20210527150541.3130505-1-punitagrawal@gmail.com>
References: <20210527150541.3130505-1-punitagrawal@gmail.com>
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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>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Rob Herring <robh+dt@kernel.org>
---
 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>,
-- 
2.30.2