[PATCH v2] PCI: rockchip: remove the pointer to L1 substate cap

[Bjorn Helgaas]

On Thu, Oct 20, 2016 at 03:53:20PM +0800, Shawn Lin wrote:
> Per the errata of TRM, the RC can't support L1 substate, so we
> need to remove the L1 substate cap as well as operation for
> PCIE_RC_CONFIG_L1_SUBSTATE_CTRL2.
> 
> Signed-off-by: Shawn Lin <shawn.lin at rock-chips.com>
> 
> Tested-by: Brian Norris <briannorris at chromium.org>

Applied to pci/host-rockchip for v4.10, thanks!

> ---
> 
> Changes in v2:
> - Add Brian's tag and remove operation for PCIE_RC_CONFIG_L1_SUBSTATE_CTRL2.
> 
>  drivers/pci/host/pcie-rockchip.c | 17 ++++++++---------
>  1 file changed, 8 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/pci/host/pcie-rockchip.c b/drivers/pci/host/pcie-rockchip.c
> index e0b22da..a23c7f1 100644
> --- a/drivers/pci/host/pcie-rockchip.c
> +++ b/drivers/pci/host/pcie-rockchip.c
> @@ -142,6 +142,8 @@
>  #define   PCIE_RC_CONFIG_LCS_LBMS		BIT(30)
>  #define   PCIE_RC_CONFIG_LCS_LAMS		BIT(31)
>  #define PCIE_RC_CONFIG_L1_SUBSTATE_CTRL2 (PCIE_RC_CONFIG_BASE + 0x90c)
> +#define PCIE_RC_CONFIG_THP_CAP		(PCIE_RC_CONFIG_BASE + 0x274)
> +#define   PCIE_RC_CONFIG_THP_CAP_NEXT_MASK	GENMASK(31, 20)
>  
>  #define PCIE_CORE_AXI_CONF_BASE		0xc00000
>  #define PCIE_CORE_OB_REGION_ADDR0	(PCIE_CORE_AXI_CONF_BASE + 0x0)
> @@ -481,15 +483,6 @@ static int rockchip_pcie_init_port(struct rockchip_pcie *rockchip)
>  		return err;
>  	}
>  
> -	/*
> -	 * We need to read/write PCIE_RC_CONFIG_L1_SUBSTATE_CTRL2 before
> -	 * enabling ASPM.  Otherwise L1PwrOnSc and L1PwrOnVal isn't
> -	 * reliable and enabling ASPM doesn't work.  This is a controller
> -	 * bug we need to work around.
> -	 */
> -	status = rockchip_pcie_read(rockchip, PCIE_RC_CONFIG_L1_SUBSTATE_CTRL2);
> -	rockchip_pcie_write(rockchip, status, PCIE_RC_CONFIG_L1_SUBSTATE_CTRL2);
> -
>  	/* Fix the transmitted FTS count desired to exit from L0s. */
>  	status = rockchip_pcie_read(rockchip, PCIE_CORE_CTRL_PLC1);
>  	status = (status & PCIE_CORE_CTRL_PLC1_FTS_MASK) |
> @@ -558,6 +551,12 @@ static int rockchip_pcie_init_port(struct rockchip_pcie *rockchip)
>  	rockchip_pcie_write(rockchip,
>  			    PCI_CLASS_BRIDGE_PCI << PCIE_RC_CONFIG_SCC_SHIFT,
>  			    PCIE_RC_CONFIG_RID_CCR);
> +
> +	/* Clear THP cap's next cap pointer to remove L1 substate cap */
> +	status = rockchip_pcie_read(rockchip, PCIE_RC_CONFIG_THP_CAP);
> +	status &= ~PCIE_RC_CONFIG_THP_CAP_NEXT_MASK;
> +	rockchip_pcie_write(rockchip, status, PCIE_RC_CONFIG_THP_CAP);
> +
>  	rockchip_pcie_write(rockchip, 0x0, PCIE_RC_BAR_CONF);
>  
>  	rockchip_pcie_write(rockchip,
> -- 
> 2.3.7
> 
> 
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