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USB: support for autosuspend in sierra while online
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This implements support for autosuspend in the sierra driver while online.
Remote wakeup is used for reception. Transmission is facilitated with a queue
and the asynchronous autopm mechanism. To prevent races a private flag
for opened ports and a counter of running transmissions needs to be added.

Signed-off-by: Oliver Neukum <oliver@neukum.org>
Tested-by: Elina Pasheva <epasheva@sierrawireless.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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Oliver Neukum authored and Greg Kroah-Hartman committed Sep 23, 2009
1 parent ad45f1d commit e6929a9
Showing 1 changed file with 152 additions and 5 deletions.
157 changes: 152 additions & 5 deletions drivers/usb/serial/sierra.c
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Original file line number Diff line number Diff line change
Expand Up @@ -51,6 +51,12 @@ struct sierra_iface_info {
const u8 *ifaceinfo; /* pointer to the array holding the numbers */
};

struct sierra_intf_private {
spinlock_t susp_lock;
unsigned int suspended:1;
int in_flight;
};

static int sierra_set_power_state(struct usb_device *udev, __u16 swiState)
{
int result;
Expand Down Expand Up @@ -144,6 +150,7 @@ static int sierra_probe(struct usb_serial *serial,
{
int result = 0;
struct usb_device *udev;
struct sierra_intf_private *data;
u8 ifnum;

udev = serial->dev;
Expand Down Expand Up @@ -171,6 +178,11 @@ static int sierra_probe(struct usb_serial *serial,
return -ENODEV;
}

data = serial->private = kzalloc(sizeof(struct sierra_intf_private), GFP_KERNEL);
if (!data)
return -ENOMEM;
spin_lock_init(&data->susp_lock);

return result;
}

Expand Down Expand Up @@ -261,13 +273,18 @@ static struct usb_driver sierra_driver = {
.name = "sierra",
.probe = usb_serial_probe,
.disconnect = usb_serial_disconnect,
.suspend = usb_serial_suspend,
.resume = usb_serial_resume,
.id_table = id_table,
.no_dynamic_id = 1,
.supports_autosuspend = 1,
};

struct sierra_port_private {
spinlock_t lock; /* lock the structure */
int outstanding_urbs; /* number of out urbs in flight */
struct usb_anchor active;
struct usb_anchor delayed;

/* Input endpoints and buffers for this port */
struct urb *in_urbs[N_IN_URB];
Expand All @@ -279,6 +296,8 @@ struct sierra_port_private {
int dsr_state;
int dcd_state;
int ri_state;

unsigned int opened:1;
};

static int sierra_send_setup(struct usb_serial_port *port)
Expand Down Expand Up @@ -390,21 +409,25 @@ static void sierra_outdat_callback(struct urb *urb)
{
struct usb_serial_port *port = urb->context;
struct sierra_port_private *portdata = usb_get_serial_port_data(port);
struct sierra_intf_private *intfdata;
int status = urb->status;
unsigned long flags;

dev_dbg(&port->dev, "%s - port %d\n", __func__, port->number);
intfdata = port->serial->private;

/* free up the transfer buffer, as usb_free_urb() does not do this */
kfree(urb->transfer_buffer);

usb_autopm_put_interface_async(port->serial->interface);
if (status)
dev_dbg(&port->dev, "%s - nonzero write bulk status "
"received: %d\n", __func__, status);

spin_lock_irqsave(&portdata->lock, flags);
spin_lock(&portdata->lock);
--portdata->outstanding_urbs;
spin_unlock_irqrestore(&portdata->lock, flags);
spin_unlock(&portdata->lock);
spin_lock(&intfdata->susp_lock);
--intfdata->in_flight;
spin_unlock(&intfdata->susp_lock);

usb_serial_port_softint(port);
}
Expand All @@ -414,6 +437,7 @@ static int sierra_write(struct tty_struct *tty, struct usb_serial_port *port,
const unsigned char *buf, int count)
{
struct sierra_port_private *portdata = usb_get_serial_port_data(port);
struct sierra_intf_private *intfdata;
struct usb_serial *serial = port->serial;
unsigned long flags;
unsigned char *buffer;
Expand All @@ -426,9 +450,9 @@ static int sierra_write(struct tty_struct *tty, struct usb_serial_port *port,
return 0;

portdata = usb_get_serial_port_data(port);
intfdata = serial->private;

dev_dbg(&port->dev, "%s: write (%zd bytes)\n", __func__, writesize);

spin_lock_irqsave(&portdata->lock, flags);
dev_dbg(&port->dev, "%s - outstanding_urbs: %d\n", __func__,
portdata->outstanding_urbs);
Expand All @@ -442,6 +466,14 @@ static int sierra_write(struct tty_struct *tty, struct usb_serial_port *port,
portdata->outstanding_urbs);
spin_unlock_irqrestore(&portdata->lock, flags);

retval = usb_autopm_get_interface_async(serial->interface);
if (retval < 0) {
spin_lock_irqsave(&portdata->lock, flags);
portdata->outstanding_urbs--;
spin_unlock_irqrestore(&portdata->lock, flags);
goto error_simple;
}

buffer = kmalloc(writesize, GFP_ATOMIC);
if (!buffer) {
dev_err(&port->dev, "out of memory\n");
Expand All @@ -468,14 +500,29 @@ static int sierra_write(struct tty_struct *tty, struct usb_serial_port *port,
/* Handle the need to send a zero length packet */
urb->transfer_flags |= URB_ZERO_PACKET;

spin_lock_irqsave(&intfdata->susp_lock, flags);

if (intfdata->suspended) {
usb_anchor_urb(urb, &portdata->delayed);
spin_unlock_irqrestore(&intfdata->susp_lock, flags);
goto skip_power;
} else {
usb_anchor_urb(urb, &portdata->active);
}
/* send it down the pipe */
retval = usb_submit_urb(urb, GFP_ATOMIC);
if (retval) {
usb_unanchor_urb(urb);
spin_unlock_irqrestore(&intfdata->susp_lock, flags);
dev_err(&port->dev, "%s - usb_submit_urb(write bulk) failed "
"with status = %d\n", __func__, retval);
goto error;
} else {
intfdata->in_flight++;
spin_unlock_irqrestore(&intfdata->susp_lock, flags);
}

skip_power:
/* we are done with this urb, so let the host driver
* really free it when it is finished with it */
usb_free_urb(urb);
Expand All @@ -491,6 +538,8 @@ static int sierra_write(struct tty_struct *tty, struct usb_serial_port *port,
dev_dbg(&port->dev, "%s - 2. outstanding_urbs: %d\n", __func__,
portdata->outstanding_urbs);
spin_unlock_irqrestore(&portdata->lock, flags);
usb_autopm_put_interface_async(serial->interface);
error_simple:
return retval;
}

Expand Down Expand Up @@ -530,6 +579,7 @@ static void sierra_indat_callback(struct urb *urb)

/* Resubmit urb so we continue receiving */
if (port->port.count && status != -ESHUTDOWN && status != -EPERM) {
usb_mark_last_busy(port->serial->dev);
err = usb_submit_urb(urb, GFP_ATOMIC);
if (err)
dev_err(&port->dev, "resubmit read urb failed."
Expand Down Expand Up @@ -591,6 +641,7 @@ static void sierra_instat_callback(struct urb *urb)

/* Resubmit urb so we continue receiving IRQ data */
if (port->port.count && status != -ESHUTDOWN && status != -ENOENT) {
usb_mark_last_busy(serial->dev);
urb->dev = serial->dev;
err = usb_submit_urb(urb, GFP_ATOMIC);
if (err)
Expand Down Expand Up @@ -711,6 +762,8 @@ static void sierra_close(struct usb_serial_port *port)
int i;
struct usb_serial *serial = port->serial;
struct sierra_port_private *portdata;
struct sierra_intf_private *intfdata = port->serial->private;


dev_dbg(&port->dev, "%s\n", __func__);
portdata = usb_get_serial_port_data(port);
Expand All @@ -723,6 +776,10 @@ static void sierra_close(struct usb_serial_port *port)
if (!serial->disconnected)
sierra_send_setup(port);
mutex_unlock(&serial->disc_mutex);
spin_lock_irq(&intfdata->susp_lock);
portdata->opened = 0;
spin_unlock_irq(&intfdata->susp_lock);


/* Stop reading urbs */
sierra_stop_rx_urbs(port);
Expand All @@ -731,13 +788,16 @@ static void sierra_close(struct usb_serial_port *port)
sierra_release_urb(portdata->in_urbs[i]);
portdata->in_urbs[i] = NULL;
}
usb_autopm_get_interface(serial->interface);
serial->interface->needs_remote_wakeup = 0;
}
}

static int sierra_open(struct tty_struct *tty, struct usb_serial_port *port)
{
struct sierra_port_private *portdata;
struct usb_serial *serial = port->serial;
struct sierra_intf_private *intfdata = serial->private;
int i;
int err;
int endpoint;
Expand Down Expand Up @@ -771,6 +831,12 @@ static int sierra_open(struct tty_struct *tty, struct usb_serial_port *port)
}
sierra_send_setup(port);

serial->interface->needs_remote_wakeup = 1;
spin_lock_irq(&intfdata->susp_lock);
portdata->opened = 1;
spin_unlock_irq(&intfdata->susp_lock);
usb_autopm_put_interface(serial->interface);

return 0;
}

Expand Down Expand Up @@ -818,6 +884,8 @@ static int sierra_startup(struct usb_serial *serial)
return -ENOMEM;
}
spin_lock_init(&portdata->lock);
init_usb_anchor(&portdata->active);
init_usb_anchor(&portdata->delayed);
/* Set the port private data pointer */
usb_set_serial_port_data(port, portdata);
}
Expand All @@ -844,6 +912,83 @@ static void sierra_release(struct usb_serial *serial)
}
}

static void stop_read_write_urbs(struct usb_serial *serial)
{
int i, j;
struct usb_serial_port *port;
struct sierra_port_private *portdata;

/* Stop reading/writing urbs */
for (i = 0; i < serial->num_ports; ++i) {
port = serial->port[i];
portdata = usb_get_serial_port_data(port);
for (j = 0; j < N_IN_URB; j++)
usb_kill_urb(portdata->in_urbs[j]);
usb_kill_anchored_urbs(&portdata->active);
}
}

static int sierra_suspend(struct usb_serial *serial, pm_message_t message)
{
struct sierra_intf_private *intfdata;
int b;

if (serial->dev->auto_pm) {
intfdata = serial->private;
spin_lock_irq(&intfdata->susp_lock);
b = intfdata->in_flight;

if (b) {
spin_unlock_irq(&intfdata->susp_lock);
return -EBUSY;
} else {
intfdata->suspended = 1;
spin_unlock_irq(&intfdata->susp_lock);
}
}
stop_read_write_urbs(serial);

return 0;
}

static int sierra_resume(struct usb_serial *serial)
{
struct usb_serial_port *port;
struct sierra_intf_private *intfdata = serial->private;
struct sierra_port_private *portdata;
struct urb *urb;
int ec = 0;
int i, err;

spin_lock_irq(&intfdata->susp_lock);
for (i = 0; i < serial->num_ports; i++) {
port = serial->port[i];
portdata = usb_get_serial_port_data(port);

while ((urb = usb_get_from_anchor(&portdata->delayed))) {
usb_anchor_urb(urb, &portdata->active);
intfdata->in_flight++;
err = usb_submit_urb(urb, GFP_ATOMIC);
if (err < 0) {
intfdata->in_flight--;
usb_unanchor_urb(urb);
usb_scuttle_anchored_urbs(&portdata->delayed);
break;
}
}

if (portdata->opened) {
err = sierra_submit_rx_urbs(port, GFP_ATOMIC);
if (err)
ec++;
}
}
intfdata->suspended = 0;
spin_unlock_irq(&intfdata->susp_lock);

return ec ? -EIO : 0;
}

static struct usb_serial_driver sierra_device = {
.driver = {
.owner = THIS_MODULE,
Expand All @@ -864,6 +1009,8 @@ static struct usb_serial_driver sierra_device = {
.tiocmset = sierra_tiocmset,
.attach = sierra_startup,
.release = sierra_release,
.suspend = sierra_suspend,
.resume = sierra_resume,
.read_int_callback = sierra_instat_callback,
};

Expand Down

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