Read Completion Boundary could be 64 bytes or 128 bytes for rockchip RC. The reset value of RCB is zero which means it doesn't support RCB to be 128 bytes, however it does support that. When setting the RCB to 128 bytes, we see some significant improvment for testing NVMe with libaio. So this patch will set RC's RCB to 128 bytes. Cc: Brian Norris <briannorris@xxxxxxxxxxxx> Cc: Jeffy Chen <jeffy.chen@xxxxxxxxxxxxxx> Signed-off-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx> --- drivers/pci/host/pcie-rockchip.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/pci/host/pcie-rockchip.c b/drivers/pci/host/pcie-rockchip.c index 26ddd35..8bcd417 100644 --- a/drivers/pci/host/pcie-rockchip.c +++ b/drivers/pci/host/pcie-rockchip.c @@ -599,6 +599,11 @@ static int rockchip_pcie_init_port(struct rockchip_pcie *rockchip) status |= PCI_EXP_LNKCTL_CCC; rockchip_pcie_write(rockchip, status, PCIE_RC_CONFIG_LCS); + /* Set RC's RCB to 128 */ + status = rockchip_pcie_read(rockchip, PCIE_RC_CONFIG_LCS); + status |= PCI_EXP_LNKCTL_RCB; + rockchip_pcie_write(rockchip, status, PCIE_RC_CONFIG_LCS); + /* Enable Gen1 training */ rockchip_pcie_write(rockchip, PCIE_CLIENT_LINK_TRAIN_ENABLE, PCIE_CLIENT_CONFIG); -- 1.9.1
