Re: [PATCH v3 3/3] pci: dra7xx: use pdata callbacks to perform reset

From: Tony Lindgren
Date: Wed Jan 27 2016 - 12:31:17 EST


* Kishon Vijay Abraham I <kishon@xxxxxx> [160114 06:12]:
> Use assert/deassert callbacks populated in the platform data to
> to perform reset of PCIe.
>
> Use these callbacks until a reset controller driver is
> is available in the kernel to reset PCIe.
...

> --- a/drivers/pci/host/pci-dra7xx.c
> +++ b/drivers/pci/host/pci-dra7xx.c
> @@ -347,6 +404,10 @@ static int __init dra7xx_pcie_probe(struct platform_device *pdev)
> enum of_gpio_flags flags;
> unsigned long gpio_flags;
>
> + ret = dra7xx_pcie_reset(pdev);
> + if (ret)
> + return ret;
> +
> dra7xx = devm_kzalloc(dev, sizeof(*dra7xx), GFP_KERNEL);
> if (!dra7xx)
> return -ENOMEM;

With the hwmod data properly configured the reset already happens
for the device by the bus driver, the hwmod code in this case?

> @@ -457,6 +518,7 @@ static int __exit dra7xx_pcie_remove(struct platform_device *pdev)
> struct pcie_port *pp = &dra7xx->pp;
> struct device *dev = &pdev->dev;
> int count = dra7xx->phy_count;
> + int ret;
>
> if (pp->irq_domain)
> irq_domain_remove(pp->irq_domain);
> @@ -467,6 +529,10 @@ static int __exit dra7xx_pcie_remove(struct platform_device *pdev)
> phy_exit(dra7xx->phy[count]);
> }
>
> + ret = dra7xx_pcie_assert_reset(pdev);
> + if (ret < 0)
> + return ret;
> +
> return 0;
> }

Why do you need another reset here? Can't you just implement PM runtime
in the driver and do the usual pm_runtime_put_sync followed by
pm_runtime_disable?

Basically I'm wondering how come we need these platform data callbacks
at all.

Regards,

Tony