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Commit 97e2c402 authored by Christian Lamparter's avatar Christian Lamparter Committed by John W. Linville
Browse files

carl9170: fix usb pm suspend->resume woes 

This patch revamps some common code-paths which are
shared between (re-)initialization and suspend/resume
subroutines. It also adds some helpful comments
about quirks and associated difficulties.

It's quite big, but it should fix #25382:
<https://bugzilla.kernel.org/show_bug.cgi?id=25382

>

And hopefully the code is robust enough to deal with
all possible suspend/resume scenarios without requiring
the user to do any sort of manual and possibly
dangerous work.

Signed-off-by: default avatarChristian Lamparter <chunkeey@googlemail.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent 3b386510

drivers/net/wireless/ath/carl9170/usb.c

+37 −16
Original line number Diff line number Diff line
@@ -834,7 +834,7 @@ static int carl9170_usb_load_firmware(struct ar9170 *ar) 
	if (err)

		goto err_out;



	/* firmware restarts cmd counter */

	/* now, start the command response counter */

	ar->cmd_seq = -1;



	return 0;
@@ -851,7 +851,12 @@ int carl9170_usb_restart(struct ar9170 *ar) 
	if (ar->intf->condition != USB_INTERFACE_BOUND)

		return 0;



	/* Disable command response sequence counter. */

	/*

	 * Disable the command response sequence counter check.

	 * We already know that the device/firmware is in a bad state.

	 * So, no extra points are awarded to anyone who reminds the

	 * driver about that.

	 */

	ar->cmd_seq = -2;



	err = carl9170_reboot(ar);
@@ -903,6 +908,15 @@ static int carl9170_usb_init_device(struct ar9170 *ar) 
{

	int err;



	/*

	 * The carl9170 firmware let's the driver know when it's

	 * ready for action. But we have to be prepared to gracefully

	 * handle all spurious [flushed] messages after each (re-)boot.

	 * Thus the command response counter remains disabled until it

	 * can be safely synchronized.

	 */

	ar->cmd_seq = -2;



	err = carl9170_usb_send_rx_irq_urb(ar);

	if (err)

		goto err_out;
@@ -911,14 +925,21 @@ static int carl9170_usb_init_device(struct ar9170 *ar) 
	if (err)

		goto err_unrx;



	err = carl9170_usb_open(ar);

	if (err)

		goto err_unrx;



	mutex_lock(&ar->mutex);

	err = carl9170_usb_load_firmware(ar);

	mutex_unlock(&ar->mutex);

	if (err)

		goto err_unrx;

		goto err_stop;



	return 0;



err_stop:

	carl9170_usb_stop(ar);



err_unrx:

	carl9170_usb_cancel_urbs(ar);
@@ -964,10 +985,6 @@ static void carl9170_usb_firmware_finish(struct ar9170 *ar) 
	if (err)

		goto err_freefw;



	err = carl9170_usb_open(ar);

	if (err)

		goto err_unrx;



	err = carl9170_register(ar);



	carl9170_usb_stop(ar);
@@ -1043,7 +1060,6 @@ static int carl9170_usb_probe(struct usb_interface *intf, 
	atomic_set(&ar->rx_work_urbs, 0);

	atomic_set(&ar->rx_anch_urbs, 0);

	atomic_set(&ar->rx_pool_urbs, 0);

	ar->cmd_seq = -2;



	usb_get_dev(ar->udev);
@@ -1090,10 +1106,6 @@ static int carl9170_usb_suspend(struct usb_interface *intf, 


	carl9170_usb_cancel_urbs(ar);



	/*

	 * firmware automatically reboots for usb suspend.

	 */



	return 0;

}
@@ -1106,12 +1118,20 @@ static int carl9170_usb_resume(struct usb_interface *intf) 
		return -ENODEV;



	usb_unpoison_anchored_urbs(&ar->rx_anch);

	carl9170_set_state(ar, CARL9170_STOPPED);



	err = carl9170_usb_init_device(ar);

	if (err)

		goto err_unrx;

	/*

	 * The USB documentation demands that [for suspend] all traffic

	 * to and from the device has to stop. This would be fine, but

	 * there's a catch: the device[usb phy] does not come back.

	 *

	 * Upon resume the firmware will "kill" itself and the

	 * boot-code sorts out the magic voodoo.

	 * Not very nice, but there's not much what could go wrong.

	 */

	msleep(1100);



	err = carl9170_usb_open(ar);

	err = carl9170_usb_init_device(ar);

	if (err)

		goto err_unrx;
@@ -1133,6 +1153,7 @@ static struct usb_driver carl9170_driver = { 
#ifdef CONFIG_PM

	.suspend = carl9170_usb_suspend,

	.resume = carl9170_usb_resume,

	.reset_resume = carl9170_usb_resume,

#endif /* CONFIG_PM */

};