Enable opportunistic UpdateFC and ACK to allow data link layer send pending ACKs and UpdateFC packets when link is idle instead of waiting for timers to expire. This improves the PCIe performance due to better utilization of PCIe bandwidth. Signed-off-by: Manikanta Maddireddy <mmaddireddy@xxxxxxxxxx> Acked-by: Thierry Reding <treding@xxxxxxxxxx> --- V3: No change V2: No change drivers/pci/controller/pci-tegra.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/pci/controller/pci-tegra.c b/drivers/pci/controller/pci-tegra.c index 76d913ef5bf4..b1e2e398b4e8 100644 --- a/drivers/pci/controller/pci-tegra.c +++ b/drivers/pci/controller/pci-tegra.c @@ -204,7 +204,9 @@ #define RP_ECTL_6_R2_RX_EQ_CTRL_H_1C_MASK 0xffffffff #define RP_VEND_XP 0x00000f00 -#define RP_VEND_XP_DL_UP (1 << 30) +#define RP_VEND_XP_DL_UP (1 << 30) +#define RP_VEND_XP_OPPORTUNISTIC_ACK (1 << 27) +#define RP_VEND_XP_OPPORTUNISTIC_UPDATEFC (1 << 28) #define RP_VEND_CTL1 0x00000f48 #define RP_VEND_CTL1_ERPT (1 << 13) @@ -529,6 +531,12 @@ static void tegra_pcie_enable_rp_features(struct tegra_pcie_port *port) value = readl(port->base + RP_VEND_CTL1); value |= RP_VEND_CTL1_ERPT; writel(value, port->base + RP_VEND_CTL1); + + /* Optimal settings to enhance bandwidth */ + value = readl(port->base + RP_VEND_XP); + value |= RP_VEND_XP_OPPORTUNISTIC_ACK; + value |= RP_VEND_XP_OPPORTUNISTIC_UPDATEFC; + writel(value, port->base + RP_VEND_XP); } static void tegra_pcie_program_ectl_settings(struct tegra_pcie_port *port) -- 2.17.1
