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Commit 3725d8c9 authored by Inaky Perez-Gonzalez's avatar Inaky Perez-Gonzalez
Browse files

wimax/i2400m: Implement pre/post reset support in the USB driver 



The USB stack can callback a driver is about to be reset by an
external entity and right after it, so the driver can save state and
then restore it.

This commit implements said support; it is implemented actually in the
core, bus-generic driver [i2400m_{pre,post}_reset()] and used by the
bus-specific drivers. This way the SDIO driver can also use it once
said support is brought to the SDIO stack.

Signed-off-by: default avatarInaky Perez-Gonzalez <inaky@linux.intel.com>
parent 2869da85

drivers/net/wimax/i2400m/driver.c

+81 −0
Original line number Diff line number Diff line
@@ -619,6 +619,87 @@ int i2400m_pm_notifier(struct notifier_block *notifier, 
}





/*

 * pre-reset is called before a device is going on reset

 *

 * This has to be followed by a call to i2400m_post_reset(), otherwise

 * bad things might happen.

 */

int i2400m_pre_reset(struct i2400m *i2400m)

{

	int result;

	struct device *dev = i2400m_dev(i2400m);



	d_fnstart(3, dev, "(i2400m %p)\n", i2400m);

	d_printf(1, dev, "pre-reset shut down\n");



	result = 0;

	mutex_lock(&i2400m->init_mutex);

	if (i2400m->updown) {

		netif_tx_disable(i2400m->wimax_dev.net_dev);

		__i2400m_dev_stop(i2400m);

		result = 0;

		/* down't set updown to zero -- this way

		 * post_reset can restore properly */

	}

	mutex_unlock(&i2400m->init_mutex);

	if (i2400m->bus_release)

		i2400m->bus_release(i2400m);

	d_fnend(3, dev, "(i2400m %p) = %d\n", i2400m, result);

	return result;

}

EXPORT_SYMBOL_GPL(i2400m_pre_reset);





/*

 * Restore device state after a reset

 *

 * Do the work needed after a device reset to bring it up to the same

 * state as it was before the reset.

 *

 * NOTE: this requires i2400m->init_mutex taken

 */

int i2400m_post_reset(struct i2400m *i2400m)

{

	int result = 0;

	struct device *dev = i2400m_dev(i2400m);



	d_fnstart(3, dev, "(i2400m %p)\n", i2400m);

	d_printf(1, dev, "post-reset start\n");

	if (i2400m->bus_setup) {

		result = i2400m->bus_setup(i2400m);

		if (result < 0) {

			dev_err(dev, "bus-specific setup failed: %d\n",

				result);

			goto error_bus_setup;

		}

	}

	mutex_lock(&i2400m->init_mutex);

	if (i2400m->updown) {

		result = __i2400m_dev_start(

			i2400m, I2400M_BRI_SOFT | I2400M_BRI_MAC_REINIT);

		if (result < 0)

			goto error_dev_start;

	}

	mutex_unlock(&i2400m->init_mutex);

	d_fnend(3, dev, "(i2400m %p) = %d\n", i2400m, result);

	return result;



error_dev_start:

	if (i2400m->bus_release)

		i2400m->bus_release(i2400m);

error_bus_setup:

	/* even if the device was up, it could not be recovered, so we

	 * mark it as down. */

	i2400m->updown = 0;

	wmb();		/* see i2400m->updown's documentation  */

	mutex_unlock(&i2400m->init_mutex);

	d_fnend(3, dev, "(i2400m %p) = %d\n", i2400m, result);

	return result;

}

EXPORT_SYMBOL_GPL(i2400m_post_reset);





/*

 * The device has rebooted; fix up the device and the driver

 *

drivers/net/wimax/i2400m/i2400m.h

+2 −0
Original line number Diff line number Diff line
@@ -817,6 +817,8 @@ void i2400m_put(struct i2400m *i2400m) 
}



extern int i2400m_dev_reset_handle(struct i2400m *, const char *);

extern int i2400m_pre_reset(struct i2400m *);

extern int i2400m_post_reset(struct i2400m *);



/*

 * _setup()/_release() are called by the probe/disconnect functions of

drivers/net/wimax/i2400m/usb.c

+33 −0
Original line number Diff line number Diff line
@@ -637,6 +637,37 @@ int i2400mu_reset_resume(struct usb_interface *iface) 
}





/*

 * Another driver or user space is triggering a reset on the device

 * which contains the interface passed as an argument. Cease IO and

 * save any device state you need to restore.

 *

 * If you need to allocate memory here, use GFP_NOIO or GFP_ATOMIC, if

 * you are in atomic context.

 */

static

int i2400mu_pre_reset(struct usb_interface *iface)

{

	struct i2400mu *i2400mu = usb_get_intfdata(iface);

	return i2400m_pre_reset(&i2400mu->i2400m);

}





/*

 * The reset has completed.  Restore any saved device state and begin

 * using the device again.

 *

 * If you need to allocate memory here, use GFP_NOIO or GFP_ATOMIC, if

 * you are in atomic context.

 */

static

int i2400mu_post_reset(struct usb_interface *iface)

{

	struct i2400mu *i2400mu = usb_get_intfdata(iface);

	return i2400m_post_reset(&i2400mu->i2400m);

}





static

struct usb_device_id i2400mu_id_table[] = {

	{ USB_DEVICE(0x8086, USB_DEVICE_ID_I6050) },
@@ -660,6 +691,8 @@ struct usb_driver i2400mu_driver = { 
	.reset_resume = i2400mu_reset_resume,

	.probe = i2400mu_probe,

	.disconnect = i2400mu_disconnect,

	.pre_reset = i2400mu_pre_reset,

	.post_reset = i2400mu_post_reset,

	.id_table = i2400mu_id_table,

	.supports_autosuspend = 1,

};