On Fri, Nov 10, 2017 at 10:58:41PM +0100, Marek Vasut wrote:
> From: Kazufumi Ikeda <kaz-ikeda@xxxxxxxxxxxxx>
>
> Reestablish the PCIe link very early in the resume process in case it
> went down to prevent PCI accesses from hanging the bus. Such accesses
> can happen early in the PCI resume process, in the resume_noirq, thus
> the link must be reestablished in the resume_noirq callback of the
> driver.
>
> Signed-off-by: Kazufumi Ikeda <kaz-ikeda@xxxxxxxxxxxxx>
> Signed-off-by: Gaku Inami <gaku.inami.xw@xxxxxxxxxxxxxx>
> Signed-off-by: Marek Vasut <marek.vasut+renesas@xxxxxxxxx>
> Cc: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> Cc: Phil Edworthy <phil.edworthy@xxxxxxxxxxx>
> Cc: Simon Horman <horms+renesas@xxxxxxxxxxxx>
> Cc: Wolfram Sang <wsa@xxxxxxxxxxxxx>
> Cc: linux-renesas-soc@xxxxxxxxxxxxxxx
Acked-by: Simon Horman <horms+renesas@xxxxxxxxxxxx>
> ---
> V2: - Use BIT() macro for (1 << n)
> - Since polling in rcar_pcie_wait_for_dl() uses udelay(), do not
> add extra changes to this function anymore
> - Make resume_noirq return early and clean up parenthesis therein
> ---
> drivers/pci/host/pcie-rcar.c | 20 ++++++++++++++++++++
> 1 file changed, 20 insertions(+)
>
> diff --git a/drivers/pci/host/pcie-rcar.c b/drivers/pci/host/pcie-rcar.c
> index 811e8194ef74..ab61829db389 100644
> --- a/drivers/pci/host/pcie-rcar.c
> +++ b/drivers/pci/host/pcie-rcar.c
> @@ -43,6 +43,7 @@
>
> /* Transfer control */
> #define PCIETCTLR 0x02000
> +#define DL_DOWN BIT(3)
> #define CFINIT 1
> #define PCIETSTR 0x02004
> #define DATA_LINK_ACTIVE 1
> @@ -1107,6 +1108,7 @@ static int rcar_pcie_probe(struct platform_device *pdev)
> pcie = pci_host_bridge_priv(bridge);
>
> pcie->dev = dev;
> + platform_set_drvdata(pdev, pcie);
>
> INIT_LIST_HEAD(&pcie->resources);
>
> @@ -1167,10 +1169,28 @@ static int rcar_pcie_probe(struct platform_device *pdev)
> return err;
> }
>
> +static int rcar_pcie_resume_noirq(struct device *dev)
> +{
> + struct rcar_pcie *pcie = dev_get_drvdata(dev);
> +
> + if (rcar_pci_read_reg(pcie, PMSR) &&
> + !(rcar_pci_read_reg(pcie, PCIETCTLR) & DL_DOWN))
> + return 0;
> +
> + /* Re-establish the PCIe link */
> + rcar_pci_write_reg(pcie, CFINIT, PCIETCTLR);
> + return rcar_pcie_wait_for_dl(pcie);
> +}
> +
> +static const struct dev_pm_ops rcar_pcie_pm_ops = {
> + .resume_noirq = rcar_pcie_resume_noirq,
> +};
> +
> static struct platform_driver rcar_pcie_driver = {
> .driver = {
> .name = "rcar-pcie",
> .of_match_table = rcar_pcie_of_match,
> + .pm = &rcar_pcie_pm_ops,
> .suppress_bind_attrs = true,
> },
> .probe = rcar_pcie_probe,
> --
> 2.11.0
>
