On 08/15/2017 03:03 AM, Bao Xiaowei wrote:
> For some special reset times for longer pcie devices, in this case, 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. So add the link up status judgement mechanisms.
>
Xiaowei,
Let me try to rephrase your commit message. Correct me if I get it
wrong. I think you mean
Determine PCIe link status by checking L0 state. If L0 state is detected
within 100ms, link status is reported as up.
> Signed-off-by: Bao Xiaowei <xiaowei....@nxp.com>
> ---
For future patches, please add change log here and revision number in
the subject.
> drivers/pci/pcie_layerscape.c | 25 +++++++++++++++++++++----
> drivers/pci/pcie_layerscape.h | 3 +++
> 2 files changed, 24 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/pci/pcie_layerscape.c b/drivers/pci/pcie_layerscape.c
> index 78cde21..4db95c5 100644
> --- a/drivers/pci/pcie_layerscape.c
> +++ b/drivers/pci/pcie_layerscape.c
> @@ -69,13 +69,30 @@ static int ls_pcie_ltssm(struct ls_pcie *pcie)
>
> static int ls_pcie_link_up(struct ls_pcie *pcie)
> {
> - int ltssm;
> + int ltssm, i;
>
> ltssm = ls_pcie_ltssm(pcie);
> - if (ltssm < LTSSM_PCIE_L0)
> - return 0;
>
> - return 1;
> + /*
> + * For some special reset times for longer pcie devices,
> + * the pcie device may on polling compliance state,
> + * on this state, if the device can restored to the L0 state
> + * within 100ms considers the pcie device is link up
> + */
> + if (ltssm == LTSSM_PCIE_DETECT_QUIET ||
> + ltssm == LTSSM_PCIE_DETECT_ACTIVE) {
Please explain the above two lines with comment.
> + return 0;
> + } else if (ltssm == LTSSM_PCIE_L0) {
> + return 1;
> + } else {
How about this comment?
/*
* For some devices requiring longer reset time, check if L0
* state can be reached within 100ms.
*/
> + for (i = 0; i < 100; i++) {
> + udelay(1000);
> + ltssm = ls_pcie_ltssm(pcie);
> + if (ltssm == LTSSM_PCIE_L0)
> + return 1;
> + }
> + return 0;
> + }
> }
>
> static void ls_pcie_cfg0_set_busdev(struct ls_pcie *pcie, u32 busdev)
> diff --git a/drivers/pci/pcie_layerscape.h b/drivers/pci/pcie_layerscape.h
> index 782e3ab..4313e85 100644
> --- a/drivers/pci/pcie_layerscape.h
> +++ b/drivers/pci/pcie_layerscape.h
> @@ -70,6 +70,9 @@
>
> #define LTSSM_STATE_MASK 0x3f
> #define LTSSM_PCIE_L0 0x11 /* L0 state */
> +#define LTSSM_PCIE_DETECT_QUIET 0x00 /* L0 state */
> +#define LTSSM_PCIE_DETECT_ACTIVE 0x01 /* L0 state */
> +#define LTSSM_PCIE_L0 0x11 /* L0 state */
>
> #define PCIE_DBI_SIZE 0x100000 /* 1M */
>
>
York
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