[PATCH 1/4] arm: a37xx: pci: Set Max Payload Size and Max Read Request Size to 512 bytes

Pali Rohár
2021-02-05T14:32:28Z

Fix usage of VL805 XHCI PCIe controller when it is connected via PCIe to
Armada 3720 SOC. Without this U-Boot crashes when trying to access
enumerated USB devices connected to this XHCI PCIe controller.

This should be done according to the PCIe Link Initialization sequence, as
defined in Marvell Armada 3720 Functional Specification.

Linux has this code too.

Signed-off-by: Pali Roh?r <pali@kernel.org>
---
drivers/pci/pci-aardvark.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/drivers/pci/pci-aardvark.c b/drivers/pci/pci-aardvark.c
index 8713b88461..b4e1b60240 100644
--- a/drivers/pci/pci-aardvark.c
+++ b/drivers/pci/pci-aardvark.c
@@ -42,6 +42,10 @@
#define PCIE_CORE_DEV_CTRL_STATS_REG 0xc8
#define PCIE_CORE_DEV_CTRL_STATS_RELAX_ORDER_DISABLE (0 << 4)
#define PCIE_CORE_DEV_CTRL_STATS_SNOOP_DISABLE (0 << 11)
+#define PCIE_CORE_DEV_CTRL_STATS_MAX_PAYLOAD_SIZE 0x2
+#define PCIE_CORE_DEV_CTRL_STATS_MAX_PAYLOAD_SIZE_SHIFT 5
+#define PCIE_CORE_DEV_CTRL_STATS_MAX_RD_REQ_SIZE 0x2
+#define PCIE_CORE_DEV_CTRL_STATS_MAX_RD_REQ_SIZE_SHIFT 12
#define PCIE_CORE_LINK_CTRL_STAT_REG 0xd0
#define PCIE_CORE_LINK_TRAINING BIT(5)
#define PCIE_CORE_ERR_CAPCTL_REG 0x118
@@ -534,6 +538,10 @@ static int pcie_advk_setup_hw(struct pcie_advk *pcie)

/* Set PCIe Device Control and Status 1 PF0 register */
reg = PCIE_CORE_DEV_CTRL_STATS_RELAX_ORDER_DISABLE |
+ (PCIE_CORE_DEV_CTRL_STATS_MAX_PAYLOAD_SIZE <<
+ PCIE_CORE_DEV_CTRL_STATS_MAX_PAYLOAD_SIZE_SHIFT) |
+ (PCIE_CORE_DEV_CTRL_STATS_MAX_RD_REQ_SIZE <<
+ PCIE_CORE_DEV_CTRL_STATS_MAX_RD_REQ_SIZE_SHIFT) |
PCIE_CORE_DEV_CTRL_STATS_SNOOP_DISABLE;
advk_writel(pcie, reg, PCIE_CORE_DEV_CTRL_STATS_REG);

--
2.20.1