31.12.2019 00:02, Michał Mirosław пишет:

On Tue, Dec 24, 2019 at 07:21:05AM +0300, Dmitry Osipenko wrote:

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24.12.2019 00:32, Michał Mirosław пишет:

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On Fri, Dec 20, 2019 at 07:31:08AM +0300, Dmitry Osipenko wrote:

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20.12.2019 06:56, Peter Chen пишет:

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On 19-12-20 04:52:38, Dmitry Osipenko wrote:

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--- 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);

It returns -EPROBE_DEFER when phy_tegra_usb isn't loaded.

How are other driver modules autoloaded? Isn't there an appropriate
MODALIAS or MODULE_DEVICE_TABLE in there?

Hello Michał,

The phy_tegra_usb module is fine by itself, it's getting autoloaded.

The problem is that ci_hdrc_tegra module depends on the phy_tegra_usb
module and thus the PHY module should be loaded before the CI module,
otherwise CI driver fails with the EPROBE_DEFER.

Why, then, is CI driver not being probed again after PHY driver loads?
EPROBE_DEFER is what should cause driver core to re-probe a device after
other devices appear (PHY in this case).

CI driver is getting re-probed just fine if PHY's driver module is
loaded manually after loading the CI's module. This patch removes this
necessity to manually load PHY's module.

This is just a minor convenience change that brings the CI's driver
loading behaviour on par with the behaviour of loading Tegra's EHCI
driver module.