Commit f3d47885 authored by Yinbo Zhu's avatar Yinbo Zhu Committed by Greg Kroah-Hartman
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usb: ohci-platform: fix usb disconnect issue after s4 



The ohci retaining bogus hardware states cause usb disconnect devices
connected before hibernation(s4), this issue occur when ohci-platform
driver build as a module and the built-in ohci-platform driver will
re probe and re enumerate the devices, so there will be no such problem.

Avoid retaining bogus hardware states during resume-from-hibernation.
Previously we had reset the hardware as part of preparing to reinstate
the snapshot image. But we can do better now with the new PM framework,
since we know exactly which resume operations are from hibernation.

According to the commit 'cd1965db ("USB: ohci: move ohci_pci_{
suspend,resume} to ohci-hcd.c")' and commit '6ec4beb5 ("USB: new
flag for resume-from-hibernation")', the flag "hibernated" is for
resume-from-hibernation and it should be true when usb resume from disk.

When this flag "hibernated" is set, the drivers will reset the hardware
to get rid of any existing state and make sure resume from hibernation
re-enumerates everything for ohci.

Acked-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarYinbo Zhu <zhuyinbo@loongson.cn>
Link: https://lore.kernel.org/r/20220902063639.17875-1-zhuyinbo@loongson.cn


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent a956f912

drivers/usb/host/ohci-platform.c

+24 −4
Original line number Diff line number Diff line
@@ -289,7 +289,7 @@ static int ohci_platform_suspend(struct device *dev) 
	return ret;

}



static int ohci_platform_resume(struct device *dev)

static int ohci_platform_resume_common(struct device *dev, bool hibernated)

{

	struct usb_hcd *hcd = dev_get_drvdata(dev);

	struct usb_ohci_pdata *pdata = dev_get_platdata(dev);
@@ -301,7 +301,7 @@ static int ohci_platform_resume(struct device *dev) 
			return err;

	}



	ohci_resume(hcd, false);

	ohci_resume(hcd, hibernated);



	pm_runtime_disable(dev);

	pm_runtime_set_active(dev);
@@ -309,6 +309,16 @@ static int ohci_platform_resume(struct device *dev) 


	return 0;

}



static int ohci_platform_resume(struct device *dev)

{

	return ohci_platform_resume_common(dev, false);

}



static int ohci_platform_restore(struct device *dev)

{

	return ohci_platform_resume_common(dev, true);

}

#endif /* CONFIG_PM_SLEEP */



static const struct of_device_id ohci_platform_ids[] = {
@@ -325,8 +335,16 @@ static const struct platform_device_id ohci_platform_table[] = { 
};

MODULE_DEVICE_TABLE(platform, ohci_platform_table);



static SIMPLE_DEV_PM_OPS(ohci_platform_pm_ops, ohci_platform_suspend,

	ohci_platform_resume);

#ifdef CONFIG_PM_SLEEP

static const struct dev_pm_ops ohci_platform_pm_ops = {

	.suspend = ohci_platform_suspend,

	.resume = ohci_platform_resume,

	.freeze = ohci_platform_suspend,

	.thaw = ohci_platform_resume,

	.poweroff = ohci_platform_suspend,

	.restore = ohci_platform_restore,

};

#endif



static struct platform_driver ohci_platform_driver = {

	.id_table	= ohci_platform_table,
@@ -335,7 +353,9 @@ static struct platform_driver ohci_platform_driver = { 
	.shutdown	= usb_hcd_platform_shutdown,

	.driver		= {

		.name	= "ohci-platform",

#ifdef CONFIG_PM_SLEEP

		.pm	= &ohci_platform_pm_ops,

#endif

		.of_match_table = ohci_platform_ids,

		.probe_type = PROBE_PREFER_ASYNCHRONOUS,

	}