On 11/10/2017 09:59 AM, Simon Horman wrote:
> Hi Marek,
Hi Simon,
> 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?
Yes, I'll also add a patch to the series to convert all the others to
the BIT() macro, to keep things consistent.
>> #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.
I can actually get rid of this altogether.
>> {
>> 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.
See above
>> }
>>
>> 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!):
This should work.
> 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
>>
--
Best regards,
Marek Vasut
