Hi Marek,
On Wed, Nov 08, 2017 at 10:28:04AM +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: Simon Horman <horms+renesas@xxxxxxxxxxxx>
> Cc: Wolfram Sang <wsa@xxxxxxxxxxxxx>
> Cc: linux-renesas-soc@xxxxxxxxxxxxxxx
For patch-sets (with more than one patch) please provide a cover-letter.
The --cover-letter option to git format-patch can help.
> ---
> drivers/pci/host/pcie-rcar.c | 31 ++++++++++++++++++++++++++++---
> 1 file changed, 28 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/pci/host/pcie-rcar.c b/drivers/pci/host/pcie-rcar.c
> index 889603783f01..aa588a7d4811 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 (1 << 3)
Can you use the BIT() macro here?
> #define CFINIT 1
> #define PCIETSTR 0x02004
> #define DATA_LINK_ACTIVE 1
> @@ -529,7 +530,7 @@ static void phy_write_reg(struct rcar_pcie *pcie,
> phy_wait_for_ack(pcie);
> }
>
> -static int rcar_pcie_wait_for_dl(struct rcar_pcie *pcie)
> +static int rcar_pcie_wait_for_dl(struct rcar_pcie *pcie, int atomic)
As Sergei mentioned bool seems like a more appropriate type for atomic.
> {
> unsigned int timeout = 10;
>
> @@ -537,7 +538,10 @@ static int rcar_pcie_wait_for_dl(struct rcar_pcie *pcie)
> if ((rcar_pci_read_reg(pcie, PCIETSTR) & DATA_LINK_ACTIVE))
> return 0;
>
> - msleep(5);
> + if (atomic)
> + mdelay(5);
> + else
> + msleep(5);
If we must delay, then I suppose this is reasonable.
> }
>
> return -ETIMEDOUT;
> @@ -595,7 +599,7 @@ static int rcar_pcie_hw_init(struct rcar_pcie *pcie)
> rcar_pci_write_reg(pcie, CFINIT, PCIETCTLR);
>
> /* This will timeout if we don't have a link. */
> - err = rcar_pcie_wait_for_dl(pcie);
> + err = rcar_pcie_wait_for_dl(pcie, 0);
> if (err)
> return err;
>
> @@ -1110,6 +1114,7 @@ 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);
>
> @@ -1173,10 +1178,30 @@ 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);
> + u32 val = rcar_pci_read_reg(pcie, PMSR);
> + int ret = 0;
> +
> + if ((val == 0) || (rcar_pci_read_reg(pcie, PCIETCTLR) & DL_DOWN)) {
Please remove the unnecessary parentheses from the line above.
Also, I would prefer if the function returned early.
Something like (completely untested!):
if (rcar_pci_read_reg(pcie, PMSR) &&
!(rcar_pci_read_reg(pcie, PCIETCTLR) & DL_DOWN))
return 0;
rcar_pci_write_reg(pcie, CFINIT, PCIETCTLR);
return rcar_pcie_wait_for_dl(pcie, 1);
> + /* Re-establish the PCIe link */
> + rcar_pci_write_reg(pcie, CFINIT, PCIETCTLR);
> + ret = rcar_pcie_wait_for_dl(pcie, 1);
> + }
> +
> + return ret;
> +}
> +
> +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
>
