On Thu, Aug 25, 2016 at 04:03:34PM +0800, Shawn Lin wrote:
> This is a bug of controller found recently which makes the
> default values of L1PwrOnSc and L1PwrOnVal unreliable when
> enabling ASPM. We could work around this by reading L1 substate
> control 2 register and then write back the value again.
> 
> Signed-off-by: Shawn Lin <[email protected]>

My pci/host-rockchip branch hasn't been merged anywhere, so I just folded
both these patches into the original commits.

> ---
> 
>  drivers/pci/host/pcie-rockchip.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/drivers/pci/host/pcie-rockchip.c 
> b/drivers/pci/host/pcie-rockchip.c
> index 1671d02..ed782b51 100644
> --- a/drivers/pci/host/pcie-rockchip.c
> +++ b/drivers/pci/host/pcie-rockchip.c
> @@ -40,6 +40,7 @@
>  #define PCIE_CLIENT_BASE                     0x0
>  #define PCIE_RC_CONFIG_NORMAL_BASE           0x800000
>  #define PCIE_RC_CONFIG_BASE                  0xa00000
> +#define PCIE_RC_CONFIG_L1_SUBSTATE_CTRL2     0x90c
>  #define PCIE_RC_CONFIG_LCSR                  0xd0
>  #define  PCIE_RC_CONFIG_LCSR_LBMIE           BIT(10)
>  #define  PCIE_RC_CONFIG_LCSR_LABIE           BIT(11)
> @@ -477,6 +478,18 @@ static int rockchip_pcie_init_port(struct 
> rockchip_pcie_port *port)
>               return err;
>       }
>  
> +     /*
> +      * We need to read/write PCIE_RC_CONFIG_L1_SUBSTATE_CTRL2
> +      * before enabling ASPM. Otherwise L1PwrOnSc and L1PwrOnVal isn't
> +      * reliable which makes the controller in broken state when
> +      * enabling ASPM. This is a controller's bug we need to work
> +      * around.
> +      */
> +     status = pcie_read(port,  PCIE_RC_CONFIG_BASE +
> +                               PCIE_RC_CONFIG_L1_SUBSTATE_CTRL2);
> +     pcie_write(port, status,  PCIE_RC_CONFIG_BASE +
> +                               PCIE_RC_CONFIG_L1_SUBSTATE_CTRL2);
> +
>       /* Enable Gen1 training */
>       pcie_write(port,
>                  HIWORD_UPDATE(PCIE_CLIENT_LINK_TRAIN_ENABLE,
> -- 
> 2.3.7
> 
> 

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