Commit 202ad1aa authored by Russell King (Oracle)'s avatar Russell King (Oracle) Committed by Greg Kroah-Hartman
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usb: gadget: tegra-xudc: fix PM use count underflow 



Upon resume from system suspend, the PM runtime core issues the
following warning:

tegra-xudc 3550000.usb: Runtime PM usage count underflow!

This is because tegra_xudc_resume() unconditionally calls
schedule_work(&xudc->usb_role_sw_work) whether or not anything has
changed, which causes tegra_xudc_device_mode_off() to be called
even when we're already in that mode.

Keep track of the current state of "device_mode", and only schedule
this work if it has changed from the hardware state on resume.

Signed-off-by: default avatar"Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>
Link: https://lore.kernel.org/r/E1uhtkH-007KDZ-JT@rmk-PC.armlinux.org.uk


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent e664036c

drivers/usb/gadget/udc/tegra-xudc.c

+7 −2
Original line number Diff line number Diff line
@@ -502,6 +502,7 @@ struct tegra_xudc { 
	struct clk_bulk_data *clks;



	bool device_mode;

	bool current_device_mode;

	struct work_struct usb_role_sw_work;



	struct phy **usb3_phy;
@@ -715,6 +716,8 @@ static void tegra_xudc_device_mode_on(struct tegra_xudc *xudc) 


	phy_set_mode_ext(xudc->curr_utmi_phy, PHY_MODE_USB_OTG,

			 USB_ROLE_DEVICE);



	xudc->current_device_mode = true;

}



static void tegra_xudc_device_mode_off(struct tegra_xudc *xudc)
@@ -725,6 +728,8 @@ static void tegra_xudc_device_mode_off(struct tegra_xudc *xudc) 


	dev_dbg(xudc->dev, "device mode off\n");



	xudc->current_device_mode = false;



	connected = !!(xudc_readl(xudc, PORTSC) & PORTSC_CCS);



	reinit_completion(&xudc->disconnect_complete);
@@ -4044,9 +4049,9 @@ static int __maybe_unused tegra_xudc_resume(struct device *dev) 


	spin_lock_irqsave(&xudc->lock, flags);

	xudc->suspended = false;

	spin_unlock_irqrestore(&xudc->lock, flags);



	if (xudc->device_mode != xudc->current_device_mode)

		schedule_work(&xudc->usb_role_sw_work);

	spin_unlock_irqrestore(&xudc->lock, flags);



	pm_runtime_enable(dev);