Commit 972e6a99 authored by Alan Stern's avatar Alan Stern Committed by Jiri Kosina
Browse files

HID: usbhid: fix inconsistent reset/resume/reset-resume behavior 



The usbhid driver has inconsistently duplicated code in its post-reset,
resume, and reset-resume pathways.

	reset-resume doesn't check HID_STARTED before trying to
	restart the I/O queues.

	resume fails to clear the HID_SUSPENDED flag if HID_STARTED
	isn't set.

	resume calls usbhid_restart_queues() with usbhid->lock held
	and the others call it without holding the lock.

The first item in particular causes a problem following a reset-resume
if the driver hasn't started up its I/O.  URB submission fails because
usbhid->urbin is NULL, and this triggers an unending reset-retry loop.

This patch fixes the problem by creating a new subroutine,
hid_restart_io(), to carry out all the common activities.  It also
adds some checks that were missing in the original code:

	After a reset, there's no need to clear any halted endpoints.

	After a resume, if a reset is pending there's no need to
	restart any I/O until the reset is finished.

	After a resume, if the interrupt-IN endpoint is halted there's
	no need to submit the input URB until the halt has been
	cleared.

Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Reported-by: default avatarDaniel Fraga <fragabr@gmail.com>
Tested-by: default avatarDaniel Fraga <fragabr@gmail.com>
CC: <stable@vger.kernel.org>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
parent d3059673

drivers/hid/usbhid/hid-core.c

+37 −36
Original line number Diff line number Diff line
@@ -951,14 +951,6 @@ static int usbhid_output_report(struct hid_device *hid, __u8 *buf, size_t count) 
	return ret;

}



static void usbhid_restart_queues(struct usbhid_device *usbhid)

{

	if (usbhid->urbout && !test_bit(HID_OUT_RUNNING, &usbhid->iofl))

		usbhid_restart_out_queue(usbhid);

	if (!test_bit(HID_CTRL_RUNNING, &usbhid->iofl))

		usbhid_restart_ctrl_queue(usbhid);

}



static void hid_free_buffers(struct usb_device *dev, struct hid_device *hid)

{

	struct usbhid_device *usbhid = hid->driver_data;
@@ -1404,6 +1396,37 @@ static void hid_cease_io(struct usbhid_device *usbhid) 
	usb_kill_urb(usbhid->urbout);

}



static void hid_restart_io(struct hid_device *hid)

{

	struct usbhid_device *usbhid = hid->driver_data;

	int clear_halt = test_bit(HID_CLEAR_HALT, &usbhid->iofl);

	int reset_pending = test_bit(HID_RESET_PENDING, &usbhid->iofl);



	spin_lock_irq(&usbhid->lock);

	clear_bit(HID_SUSPENDED, &usbhid->iofl);

	usbhid_mark_busy(usbhid);



	if (clear_halt || reset_pending)

		schedule_work(&usbhid->reset_work);

	usbhid->retry_delay = 0;

	spin_unlock_irq(&usbhid->lock);



	if (reset_pending || !test_bit(HID_STARTED, &usbhid->iofl))

		return;



	if (!clear_halt) {

		if (hid_start_in(hid) < 0)

			hid_io_error(hid);

	}



	spin_lock_irq(&usbhid->lock);

	if (usbhid->urbout && !test_bit(HID_OUT_RUNNING, &usbhid->iofl))

		usbhid_restart_out_queue(usbhid);

	if (!test_bit(HID_CTRL_RUNNING, &usbhid->iofl))

		usbhid_restart_ctrl_queue(usbhid);

	spin_unlock_irq(&usbhid->lock);

}



/* Treat USB reset pretty much the same as suspend/resume */

static int hid_pre_reset(struct usb_interface *intf)

{
@@ -1453,14 +1476,14 @@ static int hid_post_reset(struct usb_interface *intf) 
		return 1;

	}



	/* No need to do another reset or clear a halted endpoint */

	spin_lock_irq(&usbhid->lock);

	clear_bit(HID_RESET_PENDING, &usbhid->iofl);

	clear_bit(HID_CLEAR_HALT, &usbhid->iofl);

	spin_unlock_irq(&usbhid->lock);

	hid_set_idle(dev, intf->cur_altsetting->desc.bInterfaceNumber, 0, 0);

	status = hid_start_in(hid);

	if (status < 0)

		hid_io_error(hid);

	usbhid_restart_queues(usbhid);



	hid_restart_io(hid);



	return 0;

}
@@ -1483,25 +1506,9 @@ void usbhid_put_power(struct hid_device *hid) 
#ifdef CONFIG_PM

static int hid_resume_common(struct hid_device *hid, bool driver_suspended)

{

	struct usbhid_device *usbhid = hid->driver_data;

	int status;



	spin_lock_irq(&usbhid->lock);

	clear_bit(HID_SUSPENDED, &usbhid->iofl);

	usbhid_mark_busy(usbhid);



	if (test_bit(HID_CLEAR_HALT, &usbhid->iofl) ||

			test_bit(HID_RESET_PENDING, &usbhid->iofl))

		schedule_work(&usbhid->reset_work);

	usbhid->retry_delay = 0;



	usbhid_restart_queues(usbhid);

	spin_unlock_irq(&usbhid->lock);



	status = hid_start_in(hid);

	if (status < 0)

		hid_io_error(hid);

	int status = 0;



	hid_restart_io(hid);

	if (driver_suspended && hid->driver && hid->driver->resume)

		status = hid->driver->resume(hid);

	return status;
@@ -1570,12 +1577,8 @@ static int hid_suspend(struct usb_interface *intf, pm_message_t message) 
static int hid_resume(struct usb_interface *intf)

{

	struct hid_device *hid = usb_get_intfdata (intf);

	struct usbhid_device *usbhid = hid->driver_data;

	int status;



	if (!test_bit(HID_STARTED, &usbhid->iofl))

		return 0;



	status = hid_resume_common(hid, true);

	dev_dbg(&intf->dev, "resume status %d\n", status);

	return 0;
@@ -1584,10 +1587,8 @@ static int hid_resume(struct usb_interface *intf) 
static int hid_reset_resume(struct usb_interface *intf)

{

	struct hid_device *hid = usb_get_intfdata(intf);

	struct usbhid_device *usbhid = hid->driver_data;

	int status;



	clear_bit(HID_SUSPENDED, &usbhid->iofl);

	status = hid_post_reset(intf);

	if (status >= 0 && hid->driver && hid->driver->reset_resume) {

		int ret = hid->driver->reset_resume(hid);

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