Commit 9bd9c802 authored by Mathias Nyman's avatar Mathias Nyman Committed by Greg Kroah-Hartman
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usb: hub: Fix flushing of delayed work used for post resume purposes 



Delayed work that prevents USB3 hubs from runtime-suspending too early
needed to be flushed in hub_quiesce() to resolve issues detected on
QC SC8280XP CRD board during suspend resume testing.

This flushing did however trigger new issues on Raspberry Pi 3B+, which
doesn't have USB3 ports, and doesn't queue any post resume delayed work.

The flushed 'hub->init_work' item is used for several purposes, and
is originally initialized with a 'NULL' work function. The work function
is also changed on the fly, which may contribute to the issue.

Solve this by creating a dedicated delayed work item for post resume work,
and flush that delayed work in hub_quiesce()

Cc: stable <stable@kernel.org>
Fixes: a49e1e2e ("usb: hub: Fix flushing and scheduling of delayed work that tunes runtime pm")
Reported-by: default avatarMark Brown <broonie@kernel.org>
Closes: https://lore.kernel.org/linux-usb/aF5rNp1l0LWITnEB@finisterre.sirena.org.uk


Signed-off-by: default avatarMathias Nyman <mathias.nyman@linux.intel.com>
Tested-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com> # SC8280XP CRD
Tested-by: default avatarMark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20250627164348.3982628-2-mathias.nyman@linux.intel.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent efe3e3ae

drivers/usb/core/hub.c

+8 −13
Original line number Diff line number Diff line
@@ -1074,12 +1074,11 @@ int usb_remove_device(struct usb_device *udev) 


enum hub_activation_type {

	HUB_INIT, HUB_INIT2, HUB_INIT3,		/* INITs must come first */

	HUB_POST_RESET, HUB_RESUME, HUB_RESET_RESUME, HUB_POST_RESUME,

	HUB_POST_RESET, HUB_RESUME, HUB_RESET_RESUME,

};



static void hub_init_func2(struct work_struct *ws);

static void hub_init_func3(struct work_struct *ws);

static void hub_post_resume(struct work_struct *ws);



static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)

{
@@ -1103,12 +1102,6 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type) 
		goto init3;

	}



	if (type == HUB_POST_RESUME) {

		usb_autopm_put_interface_async(to_usb_interface(hub->intfdev));

		hub_put(hub);

		return;

	}



	hub_get(hub);



	/* The superspeed hub except for root hub has to use Hub Depth
@@ -1362,8 +1355,8 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type) 
		usb_autopm_get_interface_no_resume(

			to_usb_interface(hub->intfdev));



		INIT_DELAYED_WORK(&hub->init_work, hub_post_resume);

		queue_delayed_work(system_power_efficient_wq, &hub->init_work,

		queue_delayed_work(system_power_efficient_wq,

				   &hub->post_resume_work,

				   msecs_to_jiffies(USB_SS_PORT_U0_WAKE_TIME));

		return;

	}
@@ -1388,9 +1381,10 @@ static void hub_init_func3(struct work_struct *ws) 


static void hub_post_resume(struct work_struct *ws)

{

	struct usb_hub *hub = container_of(ws, struct usb_hub, init_work.work);

	struct usb_hub *hub = container_of(ws, struct usb_hub, post_resume_work.work);



	hub_activate(hub, HUB_POST_RESUME);

	usb_autopm_put_interface_async(to_usb_interface(hub->intfdev));

	hub_put(hub);

}



enum hub_quiescing_type {
@@ -1418,7 +1412,7 @@ static void hub_quiesce(struct usb_hub *hub, enum hub_quiescing_type type) 


	/* Stop hub_wq and related activity */

	timer_delete_sync(&hub->irq_urb_retry);

	flush_delayed_work(&hub->init_work);

	flush_delayed_work(&hub->post_resume_work);

	usb_kill_urb(hub->urb);

	if (hub->has_indicators)

		cancel_delayed_work_sync(&hub->leds);
@@ -1977,6 +1971,7 @@ static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id) 
	hub->hdev = hdev;

	INIT_DELAYED_WORK(&hub->leds, led_work);

	INIT_DELAYED_WORK(&hub->init_work, NULL);

	INIT_DELAYED_WORK(&hub->post_resume_work, hub_post_resume);

	INIT_WORK(&hub->events, hub_event);

	INIT_LIST_HEAD(&hub->onboard_devs);

	spin_lock_init(&hub->irq_urb_lock);

drivers/usb/core/hub.h

+1 −0
Original line number Diff line number Diff line
@@ -70,6 +70,7 @@ struct usb_hub { 
	u8			indicator[USB_MAXCHILDREN];

	struct delayed_work	leds;

	struct delayed_work	init_work;

	struct delayed_work	post_resume_work;

	struct work_struct      events;

	spinlock_t		irq_urb_lock;

	struct timer_list	irq_urb_retry;