On Mon, Nov 05, 2018 at 06:11:36PM +0000, Trent Piepho wrote:
> Eliminate imx6_pcie_link_up() so that the default handler,
> dw_pcie_link_up(), is used instead. The default handler has the correct
> code, which checks for link up and also not still training.
>
> This bug was fixed some time ago, but the fix was lost in the merge
> commit 562df5c8521e ("Merge branch 'pci/host-designware' into next").
>
> This was due to the interaction for two commits on either branch of the
> merge. Commit 4d107d3b5a68 ("PCI: imx6: Move link up check into
> imx6_pcie_wait_for_link()"), changed imx6_pcie_wait_for_link() to poll
> the link status register directly, checking for link up and not
> training, and made imx6_pcie_link_up() only check the link up bit (once,
> not a polling loop).
>
> While commit commit 886bc5ceb5cc ("PCI: designware: Add generic
> dw_pcie_wait_for_link()"), replaced the loop in
> imx6_pcie_wait_for_link() with a call to a new dwc core function, which
> polled imx6_pcie_link_up(), which still checked both link up and not
> training in a loop.
>
> When these two commits were merged, the version of
> imx6_pcie_wait_for_link() from '886 was kept, which eliminated the link
> training check placed there by '4d1. But the version of
> imx6_pcie_link_up() from '4d1 was kept, which eliminated the link
> training check that had been there and was moved to
> imx6_pcie_wait_for_link().
>
> And the result was the link training check got lost for the imx6 driver.
>
> Fixes: 562df5c8521e ("Merge branch 'pci/host-designware' into next")
> Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> Cc: Joao Pinto <Joao.Pinto@xxxxxxxxxxxx>
> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
> Cc: Richard Zhu <hongxing.zhu@xxxxxxx>
> Reviewed-by: Lucas Stach <l.stach@xxxxxxxxxxxxxx>
> Signed-off-by: Trent Piepho <tpiepho@xxxxxxxxxx>
> ---
> drivers/pci/controller/dwc/pci-imx6.c | 10 +---------
> 1 file changed, 1 insertion(+), 9 deletions(-)
I have applied it to pci/controller-fixes for one of the upcoming -rc*.
Thanks,
Lorenzo
> diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
> index 4a9a673b4777..975050a69494 100644
> --- a/drivers/pci/controller/dwc/pci-imx6.c
> +++ b/drivers/pci/controller/dwc/pci-imx6.c
> @@ -80,8 +80,6 @@ struct imx6_pcie {
> #define PCIE_PL_PFLR_FORCE_LINK (1 << 15)
> #define PCIE_PHY_DEBUG_R0 (PL_OFFSET + 0x28)
> #define PCIE_PHY_DEBUG_R1 (PL_OFFSET + 0x2c)
> -#define PCIE_PHY_DEBUG_R1_XMLH_LINK_IN_TRAINING (1 << 29)
> -#define PCIE_PHY_DEBUG_R1_XMLH_LINK_UP (1 << 4)
>
> #define PCIE_PHY_CTRL (PL_OFFSET + 0x114)
> #define PCIE_PHY_CTRL_DATA_LOC 0
> @@ -641,12 +639,6 @@ static int imx6_pcie_host_init(struct pcie_port *pp)
> return 0;
> }
>
> -static int imx6_pcie_link_up(struct dw_pcie *pci)
> -{
> - return dw_pcie_readl_dbi(pci, PCIE_PHY_DEBUG_R1) &
> - PCIE_PHY_DEBUG_R1_XMLH_LINK_UP;
> -}
> -
> static const struct dw_pcie_host_ops imx6_pcie_host_ops = {
> .host_init = imx6_pcie_host_init,
> };
> @@ -679,7 +671,7 @@ static int imx6_add_pcie_port(struct imx6_pcie *imx6_pcie,
> }
>
> static const struct dw_pcie_ops dw_pcie_ops = {
> - .link_up = imx6_pcie_link_up,
> + /* No special ops needed, but pcie-designware still expects this struct */
> };
>
> static int imx6_pcie_probe(struct platform_device *pdev)
> --
> 2.14.4
>
