openwrt/target/linux/mediatek/patches-6.6/710-pci-pcie-mediatek-add-support-for-coherent-DMA.patch
Rany Hany 8607372b41 mediatek: fix broken PCIe caused by update to 6.6.30
The patch "710-pci-pcie-mediatek-add-support-for-coherent-DMA.patch"
makes use of "syscon_regmap_lookup_by_phandle" which requires that
"syscon" be in the compatible list.

Without this patch, PCIe probe will fail with the following error:

[    1.287467] mtk-pcie 1a143000.pcie: host bridge /pcie@1a143000 ranges:
[    1.294019] mtk-pcie 1a143000.pcie: Parsing ranges property...
[    1.299901] mtk-pcie 1a143000.pcie:      MEM 0x0020000000..0x0027ffffff -> 0x0020000000
[    1.307954] mtk-pcie 1a143000.pcie: missing hifsys node
[    1.313185] mtk-pcie: probe of 1a143000.pcie failed with error -22

Fixes: 4c6e9a9943 ("kernel: bump 6.6 to 6.6.30")
Signed-off-by: Rany Hany <rany_hany@riseup.net>
2024-05-06 11:05:03 +02:00

92 lines
2.5 KiB
Diff

From: Felix Fietkau <nbd@nbd.name>
Date: Fri, 4 Sep 2020 18:42:42 +0200
Subject: [PATCH] pci: pcie-mediatek: add support for coherent DMA
It improves performance by eliminating the need for a cache flush for DMA on
attached devices
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
--- a/arch/arm64/boot/dts/mediatek/mt7622.dtsi
+++ b/arch/arm64/boot/dts/mediatek/mt7622.dtsi
@@ -832,6 +832,9 @@
bus-range = <0x00 0xff>;
ranges = <0x82000000 0 0x20000000 0x0 0x20000000 0 0x8000000>;
status = "disabled";
+ dma-coherent;
+ mediatek,hifsys = <&hifsys>;
+ mediatek,cci-control = <&cci_control2>;
#interrupt-cells = <1>;
interrupt-map-mask = <0 0 0 7>;
@@ -876,6 +879,9 @@
bus-range = <0x00 0xff>;
ranges = <0x82000000 0 0x28000000 0x0 0x28000000 0 0x8000000>;
status = "disabled";
+ dma-coherent;
+ mediatek,hifsys = <&hifsys>;
+ mediatek,cci-control = <&cci_control2>;
#interrupt-cells = <1>;
interrupt-map-mask = <0 0 0 7>;
@@ -937,7 +943,7 @@
};
hifsys: clock-controller@1af00000 {
- compatible = "mediatek,mt7622-hifsys";
+ compatible = "mediatek,mt7622-hifsys", "syscon";
reg = <0 0x1af00000 0 0x70>;
#clock-cells = <1>;
};
--- a/drivers/pci/controller/pcie-mediatek.c
+++ b/drivers/pci/controller/pcie-mediatek.c
@@ -20,6 +20,7 @@
#include <linux/of_address.h>
#include <linux/of_pci.h>
#include <linux/of_platform.h>
+#include <linux/of_address.h>
#include <linux/pci.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
@@ -139,6 +140,11 @@
#define PCIE_LINK_STATUS_V2 0x804
#define PCIE_PORT_LINKUP_V2 BIT(10)
+/* DMA channel mapping */
+#define HIFSYS_DMA_AG_MAP 0x008
+#define HIFSYS_DMA_AG_MAP_PCIE0 BIT(0)
+#define HIFSYS_DMA_AG_MAP_PCIE1 BIT(1)
+
struct mtk_pcie_port;
/**
@@ -1060,6 +1066,27 @@ static int mtk_pcie_setup(struct mtk_pci
struct mtk_pcie_port *port, *tmp;
int err, slot;
+ if (of_dma_is_coherent(node)) {
+ struct regmap *con;
+ u32 mask;
+
+ con = syscon_regmap_lookup_by_phandle(node,
+ "mediatek,cci-control");
+ /* enable CPU/bus coherency */
+ if (!IS_ERR(con))
+ regmap_write(con, 0, 3);
+
+ con = syscon_regmap_lookup_by_phandle(node,
+ "mediatek,hifsys");
+ if (IS_ERR(con)) {
+ dev_err(dev, "missing hifsys node\n");
+ return PTR_ERR(con);
+ }
+
+ mask = HIFSYS_DMA_AG_MAP_PCIE0 | HIFSYS_DMA_AG_MAP_PCIE1;
+ regmap_update_bits(con, HIFSYS_DMA_AG_MAP, mask, mask);
+ }
+
slot = of_get_pci_domain_nr(dev->of_node);
if (slot < 0) {
for_each_available_child_of_node(node, child) {