Re: [PATCH v2 3/4] usb: ehci: Add new EHCI driver for Broadcom STB SoC's

Andy Shevchenko
2020-03-28T20:18:50Z

On Fri, Mar 27, 2020 at 04:47:10PM -0400, Al Cooper wrote:
> Add a new EHCI driver for Broadcom STB SoC's. A new EHCI driver
> was created instead of adding support to the existing ehci platform
> driver because of the code required to workaround bugs in the EHCI
> controller.

I'm not sure this has been tested. See below.

...

> +#include <linux/acpi.h>
> +#include <linux/of.h>

I didn;t find evidence these are needed.

...

> + res = readl_relaxed_poll_timeout(&ehci->regs->frame_index, val,
> + (val != frame_idx), 1, 130);

Too many parentheses.

> + if (res)
> + dev_err(ehci_to_hcd(ehci)->self.controller,
> + "Error waiting for SOF\n");

...

> +static int ehci_brcm_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct resource *res_mem;
> + struct brcm_priv *priv;
> + struct usb_hcd *hcd;
> + int irq;
> + int err;
> +
> + if (usb_disabled())
> + return -ENODEV;
> +
> + err = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
> + if (err)
> + return err;
> +

> + irq = platform_get_irq(pdev, 0);
> + return irq;

I'm not sure it was an intention to leave a lot of dead code below.

> + /* Hook the hub control routine to work around a bug */

> + if (org_hub_control == NULL)

if (!org_hub_control) ?

> + org_hub_control = ehci_brcm_hc_driver.hub_control;
> + ehci_brcm_hc_driver.hub_control = ehci_brcm_hub_control;

> + device_wakeup_enable(hcd->self.controller);
> + device_enable_async_suspend(hcd->self.controller);
> + platform_set_drvdata(pdev, hcd);
> +

> + return err;

return 0; ?

> +err_clk:
> + clk_disable_unprepare(priv->clk);
> +err_hcd:
> + usb_put_hcd(hcd);
> +
> + return err;
> +}

...

> +#ifdef CONFIG_PM_SLEEP

You also can use __maybe_unused annotations.

> +static int ehci_brcm_suspend(struct device *dev)
> +{
> + int ret;
> + struct usb_hcd *hcd = dev_get_drvdata(dev);
> + struct brcm_priv *priv = hcd_to_ehci_priv(hcd);
> + bool do_wakeup = device_may_wakeup(dev);
> +

> + ret = ehci_suspend(hcd, do_wakeup);
> + clk_disable_unprepare(priv->clk);
> + return ret;

So, if you fail to suspend the device, clocks will become unusable, how to recover from such case?

> +}

> +#endif /* CONFIG_PM_SLEEP */

...

> +MODULE_DESCRIPTION(BRCM_DRIVER_DESC);

Better to have it explicit.

--
With Best Regards,
Andy Shevchenko