Commit d6edcdc1 authored by Piyush Mehta's avatar Piyush Mehta Committed by Greg Kroah-Hartman
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usb: dwc3: xilinx: fix usb3 non-wakeup source resume failure 



When USB is in super-speed mode and disabled as a wakeup source,
observed that on the resume path, lanes have not been configured
properly in the phy-zynqmp driver.
As a result, after the resume, USB device detection failed on host.

To resolved the above issue, added phy_init on resume and phy_exit
on suspend path, to configure the GT lanes correctly.
The re-initialization of phy, reset the device and re-enumerate
the USB subsystem.

This use-case is specific to Xilinx ZynqMP SoC.

Signed-off-by: default avatarPiyush Mehta <piyush.mehta@amd.com>
Link: https://lore.kernel.org/r/20220912111017.901321-3-piyush.mehta@amd.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent ec50e114

drivers/usb/dwc3/dwc3-xilinx.c

+21 −9
Original line number Diff line number Diff line
@@ -47,6 +47,7 @@ struct dwc3_xlnx { 
	struct device			*dev;

	void __iomem			*regs;

	int				(*pltfm_init)(struct dwc3_xlnx *data);

	struct phy			*usb3_phy;

};



static void dwc3_xlnx_mask_phy_rst(struct dwc3_xlnx *priv_data, bool mask)
@@ -100,13 +101,12 @@ static int dwc3_xlnx_init_zynqmp(struct dwc3_xlnx *priv_data) 
	struct device		*dev = priv_data->dev;

	struct reset_control	*crst, *hibrst, *apbrst;

	struct gpio_desc	*reset_gpio;

	struct phy		*usb3_phy;

	int			ret = 0;

	u32			reg;



	usb3_phy = devm_phy_optional_get(dev, "usb3-phy");

	if (IS_ERR(usb3_phy)) {

		ret = PTR_ERR(usb3_phy);

	priv_data->usb3_phy = devm_phy_optional_get(dev, "usb3-phy");

	if (IS_ERR(priv_data->usb3_phy)) {

		ret = PTR_ERR(priv_data->usb3_phy);

		dev_err_probe(dev, ret,

			      "failed to get USB3 PHY\n");

		goto err;
@@ -121,7 +121,7 @@ static int dwc3_xlnx_init_zynqmp(struct dwc3_xlnx *priv_data) 
	 * in use but the usb3-phy entry is missing from the device tree.

	 * Therefore, skip these operations in this case.

	 */

	if (!usb3_phy)

	if (!priv_data->usb3_phy)

		goto skip_usb3_phy;



	crst = devm_reset_control_get_exclusive(dev, "usb_crst");
@@ -166,9 +166,9 @@ static int dwc3_xlnx_init_zynqmp(struct dwc3_xlnx *priv_data) 
		goto err;

	}



	ret = phy_init(usb3_phy);

	ret = phy_init(priv_data->usb3_phy);

	if (ret < 0) {

		phy_exit(usb3_phy);

		phy_exit(priv_data->usb3_phy);

		goto err;

	}
@@ -196,9 +196,9 @@ static int dwc3_xlnx_init_zynqmp(struct dwc3_xlnx *priv_data) 
		goto err;

	}



	ret = phy_power_on(usb3_phy);

	ret = phy_power_on(priv_data->usb3_phy);

	if (ret < 0) {

		phy_exit(usb3_phy);

		phy_exit(priv_data->usb3_phy);

		goto err;

	}
@@ -350,6 +350,8 @@ static int __maybe_unused dwc3_xlnx_suspend(struct device *dev) 
{

	struct dwc3_xlnx *priv_data = dev_get_drvdata(dev);



	phy_exit(priv_data->usb3_phy);



	/* Disable the clocks */

	clk_bulk_disable(priv_data->num_clocks, priv_data->clks);
@@ -365,6 +367,16 @@ static int __maybe_unused dwc3_xlnx_resume(struct device *dev) 
	if (ret)

		return ret;



	ret = phy_init(priv_data->usb3_phy);

	if (ret < 0)

		return ret;



	ret = phy_power_on(priv_data->usb3_phy);

	if (ret < 0) {

		phy_exit(priv_data->usb3_phy);

		return ret;

	}



	return 0;

}