[U-Boot] [PATCH 3/3] Powerpc: pcie: Make pcie link state judgement more specific

[Joakim Tjernlund]

On Fri, 2017-10-20 at 18:16 +0800, Bao Xiaowei wrote:
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> 
> 
> For some special reset times for longer pcie devices, the pcie device
> may on polling compliance state, the RC considers the pcie device is
> link up, but the pcie device is not link up, only the L0 state is link
> up state.
> 
> Signed-off-by: Bao Xiaowei <xiaowei.bao at nxp.com>
> ---
>  arch/powerpc/include/asm/fsl_pci.h |  2 ++
>  drivers/pci/fsl_pci_init.c         | 10 ++++++----
>  2 files changed, 8 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/fsl_pci.h b/arch/powerpc/include/asm/fsl_pci.h
> index 70a5461..323b182 100644
> --- a/arch/powerpc/include/asm/fsl_pci.h
> +++ b/arch/powerpc/include/asm/fsl_pci.h
> @@ -25,6 +25,8 @@
>  #define PCI_LTSSM      0x404   /* PCIe Link Training, Status State Machine */
>  #define PCI_LTSSM_L0   0x16    /* L0 state */
>  #define PCI_LTSSM_L0_PEX_REV3  0x11    /* L0 state for pex rev3*/
> +#define LTSSM_PCIE_DETECT_QUIET                0x00    /* Detect state */
> +#define LTSSM_PCIE_DETECT_ACTIVE       0x01    /* Detect state */
> 
>  int fsl_setup_hose(struct pci_controller *hose, unsigned long addr);
>  int fsl_is_pci_agent(struct pci_controller *hose);
> diff --git a/drivers/pci/fsl_pci_init.c b/drivers/pci/fsl_pci_init.c
> index be57e53..9b5f386 100644
> --- a/drivers/pci/fsl_pci_init.c
> +++ b/drivers/pci/fsl_pci_init.c
> @@ -335,15 +335,17 @@ static int fsl_pci_link_up(struct pci_controller *hose,
>                 pci_ltssm_l0 = PCI_LTSSM_L0;
> 
>         ltssm = fsl_get_ltssm(hose, pci_info);
> -
> -       if (ltssm == pci_ltssm_l0) {
> +       if (ltssm == LTSSM_PCIE_DETECT_QUIET ||
> +               ltssm == LTSSM_PCIE_DETECT_ACTIVE) {
> +               enabled = 0;
> +       } else if (ltssm == pci_ltssm_l0) {
>                 enabled = 1;
>         } else {
> -               for (i = 0; i < 100 && ltssm < pci_ltssm_l0; i++) {
> +               for (i = 0; i < 100 && ltssm != pci_ltssm_l0; i++) {
>                         ltssm = fsl_get_ltssm(hose, pci_info);
>                         udelay(1000);
Do you really need this long loop here ? It causes a long delay in case the PCIe device
is in permanent polling
state. Our device is in polling state until clocks is configured
and that will be done from user space in Linux

>                 }
> -               enabled = ltssm >= pci_ltssm_l0;
> +               enabled = (ltssm == pci_ltssm_l0) ? 1 : 0;
>         }
> 
>         return enabled;
> --
> 2.7.4
> 
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