PCI: rockchip: Configure RC's MPS setting

The default value of MPS for RC is 128 bytes, but actually it could support
256 bytes.  So this patch fixes this issue.

Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

diff --git a/drivers/pci/host/pcie-rockchip.c b/drivers/pci/host/pcie-rockchip.c
index c283633..86413b8 100644 (file)
--- a/drivers/pci/host/pcie-rockchip.c
+++ b/drivers/pci/host/pcie-rockchip.c
@@ -146,6 +146,9 @@
 #define   PCIE_RC_CONFIG_DCR_CSPL_SHIFT                18
 #define   PCIE_RC_CONFIG_DCR_CSPL_LIMIT                0xff
 #define   PCIE_RC_CONFIG_DCR_CPLS_SHIFT                26
+#define PCIE_RC_CONFIG_DCSR            (PCIE_RC_CONFIG_BASE + 0xc8)
+#define   PCIE_RC_CONFIG_DCSR_MPS_MASK         GENMASK(7, 5)
+#define   PCIE_RC_CONFIG_DCSR_MPS_256          (0x1 << 5)
 #define PCIE_RC_CONFIG_LINK_CAP                (PCIE_RC_CONFIG_BASE + 0xcc)
 #define   PCIE_RC_CONFIG_LINK_CAP_L0S          BIT(10)
 #define PCIE_RC_CONFIG_LCS             (PCIE_RC_CONFIG_BASE + 0xd0)
@@ -701,6 +704,11 @@ static int rockchip_pcie_init_port(struct rockchip_pcie *rockchip)
                rockchip_pcie_write(rockchip, status, PCIE_RC_CONFIG_LINK_CAP);
        }
 
+       status = rockchip_pcie_read(rockchip, PCIE_RC_CONFIG_DCSR);
+       status &= ~PCIE_RC_CONFIG_DCSR_MPS_MASK;
+       status |= PCIE_RC_CONFIG_DCSR_MPS_256;
+       rockchip_pcie_write(rockchip, status, PCIE_RC_CONFIG_DCSR);
+
        return 0;
 }