Re: [PATCH v2 10/10] usb: chipidea: tegra: Add USB_TEGRA_PHY module to driver's dependencies

From: Peter Chen
Date: Thu Dec 19 2019 - 22:56:59 EST


On 19-12-20 04:52:38, Dmitry Osipenko wrote:
> Now, when ci_hdrc_tegra kernel module is loaded, the phy_tegra_usb module
> is loaded too regardless of kernel's configuration. Previously this
> problem was masked because Tegra's EHCI driver is usually enabled in
> kernel's config and thus PHY driver was getting loaded because of it, but
> now I was making some more thorough testing and noticed that PHY's module
> isn't getting auto-loaded without the host driver.
>
> Note that ChipIdea's driver doesn't use any of the exported functions of
> phy_tegra_usb module and thus the module needs to be requested explicitly.
>
> Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
> ---
> drivers/usb/chipidea/Kconfig | 1 +
> drivers/usb/chipidea/ci_hdrc_tegra.c | 6 ++++++
> 2 files changed, 7 insertions(+)
>
> diff --git a/drivers/usb/chipidea/Kconfig b/drivers/usb/chipidea/Kconfig
> index ae850b3fddf2..d53db520e209 100644
> --- a/drivers/usb/chipidea/Kconfig
> +++ b/drivers/usb/chipidea/Kconfig
> @@ -7,6 +7,7 @@ config USB_CHIPIDEA
> select RESET_CONTROLLER
> select USB_ULPI_BUS
> select USB_ROLE_SWITCH
> + select USB_TEGRA_PHY if ARCH_TEGRA
> help
> Say Y here if your system has a dual role high speed USB
> controller based on ChipIdea silicon IP. It supports:
> diff --git a/drivers/usb/chipidea/ci_hdrc_tegra.c b/drivers/usb/chipidea/ci_hdrc_tegra.c
> index 7455df0ede49..8bc11100245d 100644
> --- a/drivers/usb/chipidea/ci_hdrc_tegra.c
> +++ b/drivers/usb/chipidea/ci_hdrc_tegra.c
> @@ -53,6 +53,12 @@ static int tegra_udc_probe(struct platform_device *pdev)
> struct tegra_udc *udc;
> int err;
>
> + if (IS_MODULE(CONFIG_USB_TEGRA_PHY)) {
> + err = request_module("phy_tegra_usb");
> + if (err)
> + return err;
> + }
> +

Why you do this dependency, if this controller driver can't
get USB PHY, it should return error. What's the return value
after calling below:

udc->phy = devm_usb_get_phy_by_phandle(&pdev->dev, "nvidia,phy", 0);

Peter
> udc = devm_kzalloc(&pdev->dev, sizeof(*udc), GFP_KERNEL);
> if (!udc)
> return -ENOMEM;
> --
> 2.24.0
>

--

Thanks,
Peter Chen