rk3399 supports PCIe 2.x link speeds marginally at best, and on some
boards, the link won't train at 5 GT/s at all. Rather than sacrifice 500
ms waiting for training that will never happen, let's support a device
tree quirk flag to disable generation 2 speeds entirely.
Signed-off-by: Brian Norris <briannorris@xxxxxxxxxxxx>
---
.../devicetree/bindings/pci/rockchip-pcie.txt | 2 +
drivers/pci/host/pcie-rockchip.c | 57 +++++++++++++---------
2 files changed, 37 insertions(+), 22 deletions(-)
diff --git a/Documentation/devicetree/bindings/pci/rockchip-pcie.txt b/Documentation/devicetree/bindings/pci/rockchip-pcie.txt
index ba67b39939c1..e769726fd093 100644
--- a/Documentation/devicetree/bindings/pci/rockchip-pcie.txt
+++ b/Documentation/devicetree/bindings/pci/rockchip-pcie.txt
@@ -42,6 +42,8 @@ Required properties:
Optional Property:
- ep-gpios: contain the entry for pre-reset gpio
- num-lanes: number of lanes to use
+- rockchip,disable-gen2: present if PCIe generation 2.x (i.e., 5 GT/s link
+ speeds) is not supported.
- vpcie3v3-supply: The phandle to the 3.3v regulator to use for PCIe.
- vpcie1v8-supply: The phandle to the 1.8v regulator to use for PCIe.
- vpcie0v9-supply: The phandle to the 0.9v regulator to use for PCIe.
diff --git a/drivers/pci/host/pcie-rockchip.c b/drivers/pci/host/pcie-rockchip.c
index c3593e633ccd..f047c4a73f69 100644
--- a/drivers/pci/host/pcie-rockchip.c
+++ b/drivers/pci/host/pcie-rockchip.c
@@ -53,6 +53,7 @@
#define PCIE_CLIENT_ARI_ENABLE HIWORD_UPDATE_BIT(0x0008)
#define PCIE_CLIENT_CONF_LANE_NUM(x) HIWORD_UPDATE(0x0030, ENCODE_LANES(x))
#define PCIE_CLIENT_MODE_RC HIWORD_UPDATE_BIT(0x0040)
+#define PCIE_CLIENT_GEN_SEL_1 HIWORD_UPDATE(0x0080, 0)
#define PCIE_CLIENT_GEN_SEL_2 HIWORD_UPDATE_BIT(0x0080)
#define PCIE_CLIENT_BASIC_STATUS1 (PCIE_CLIENT_BASE + 0x48)
#define PCIE_CLIENT_LINK_STATUS_UP 0x00300000
@@ -191,6 +192,7 @@ struct rockchip_pcie {
struct gpio_desc *ep_gpio;
u32 lanes;
u8 root_bus_nr;
+ bool enable_gen2;
struct device *dev;
struct irq_domain *irq_domain;
};
@@ -418,13 +420,19 @@ static int rockchip_pcie_init_port(struct rockchip_pcie *rockchip)
return err;
}
+ if (rockchip->enable_gen2)
+ rockchip_pcie_write(rockchip, PCIE_CLIENT_GEN_SEL_2,
+ PCIE_CLIENT_CONFIG);
+ else
+ rockchip_pcie_write(rockchip, PCIE_CLIENT_GEN_SEL_1,
+ PCIE_CLIENT_CONFIG);
+
rockchip_pcie_write(rockchip,
PCIE_CLIENT_CONF_ENABLE |
PCIE_CLIENT_LINK_TRAIN_ENABLE |
PCIE_CLIENT_ARI_ENABLE |
PCIE_CLIENT_CONF_LANE_NUM(rockchip->lanes) |
- PCIE_CLIENT_MODE_RC |
- PCIE_CLIENT_GEN_SEL_2,
+ PCIE_CLIENT_MODE_RC,
PCIE_CLIENT_CONFIG);
err = phy_power_on(rockchip->phy);
@@ -492,29 +500,31 @@ static int rockchip_pcie_init_port(struct rockchip_pcie *rockchip)
msleep(20);
}
- /*
- * Enable retrain for gen2. This should be configured only after
- * gen1 finished.
- */
- status = rockchip_pcie_read(rockchip, PCIE_RC_CONFIG_LCS);
- status |= PCIE_RC_CONFIG_LCS_RETRAIN_LINK;
- rockchip_pcie_write(rockchip, status, PCIE_RC_CONFIG_LCS);
+ if (rockchip->enable_gen2) {
+ /*
+ * Enable retrain for gen2. This should be configured only after
+ * gen1 finished.
+ */
+ status = rockchip_pcie_read(rockchip, PCIE_RC_CONFIG_LCS);
+ status |= PCIE_RC_CONFIG_LCS_RETRAIN_LINK;
+ rockchip_pcie_write(rockchip, status, PCIE_RC_CONFIG_LCS);
+
+ timeout = jiffies + msecs_to_jiffies(500);
+ for (;;) {
+ status = rockchip_pcie_read(rockchip, PCIE_CORE_CTRL);
+ if ((status & PCIE_CORE_PL_CONF_SPEED_MASK) ==
+ PCIE_CORE_PL_CONF_SPEED_5G) {
+ dev_dbg(dev, "PCIe link training gen2 pass!\n");
+ break;
+ }
- timeout = jiffies + msecs_to_jiffies(500);
- for (;;) {
- status = rockchip_pcie_read(rockchip, PCIE_CORE_CTRL);
- if ((status & PCIE_CORE_PL_CONF_SPEED_MASK) ==
- PCIE_CORE_PL_CONF_SPEED_5G) {
- dev_dbg(dev, "PCIe link training gen2 pass!\n");
- break;
- }
+ if (time_after(jiffies, timeout)) {
+ dev_dbg(dev, "PCIe link training gen2 timeout, fall back to gen1!\n");
+ break;
+ }
- if (time_after(jiffies, timeout)) {
- dev_dbg(dev, "PCIe link training gen2 timeout, fall back to gen1!\n");
- break;
+ msleep(20);
}
-
- msleep(20);
}
/* Check the final link width from negotiated lane counter from MGMT */
@@ -722,6 +732,9 @@ static int rockchip_pcie_parse_dt(struct rockchip_pcie *rockchip)
rockchip->lanes = 1;
}
+ rockchip->enable_gen2 = !of_property_read_bool(node,
+ "rockchip,disable-gen2");
+
rockchip->core_rst = devm_reset_control_get(dev, "core");
if (IS_ERR(rockchip->core_rst)) {
if (PTR_ERR(rockchip->core_rst) != -EPROBE_DEFER)
--
2.8.0.rc3.226.g39d4020
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