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USB: cxacru: ADSL state management
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The device has commands to start/stop the ADSL function, so this adds a
sysfs attribute to allow it to be started/stopped/restarted.  It also stops
polling the device for status when the ADSL function is disabled.

There are no problems with sending multiple start or stop commands, even
with a fast loop of them the device still works.  There is no need to
protect the restart process from further user actions while it's waiting
for 1.5s.

Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
Cc: Duncan Sands <duncan.sands@math.u-psud.fr>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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Simon Arlott authored and Greg Kroah-Hartman committed Apr 27, 2007
1 parent 7d5e1dd commit 6a02c99
Showing 1 changed file with 227 additions and 9 deletions.
236 changes: 227 additions & 9 deletions drivers/usb/atm/cxacru.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,7 @@
*
* Copyright (C) 2004 David Woodhouse, Duncan Sands, Roman Kagan
* Copyright (C) 2005 Duncan Sands, Roman Kagan (rkagan % mail ! ru)
* Copyright (C) 2007 Simon Arlott
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free
Expand Down Expand Up @@ -146,6 +147,13 @@ enum cxacru_info_idx {
CXINF_MAX = 0x1c,
};

enum cxacru_poll_state {
CXPOLL_STOPPING,
CXPOLL_STOPPED,
CXPOLL_POLLING,
CXPOLL_SHUTDOWN
};

struct cxacru_modem_type {
u32 pll_f_clk;
u32 pll_b_clk;
Expand All @@ -158,8 +166,12 @@ struct cxacru_data {
const struct cxacru_modem_type *modem_type;

int line_status;
struct mutex adsl_state_serialize;
int adsl_status;
struct delayed_work poll_work;
u32 card_info[CXINF_MAX];
struct mutex poll_state_serialize;
int poll_state;

/* contol handles */
struct mutex cm_serialize;
Expand All @@ -171,10 +183,18 @@ struct cxacru_data {
struct completion snd_done;
};

static int cxacru_cm(struct cxacru_data *instance, enum cxacru_cm_request cm,
u8 *wdata, int wsize, u8 *rdata, int rsize);
static void cxacru_poll_status(struct work_struct *work);

/* Card info exported through sysfs */
#define CXACRU__ATTR_INIT(_name) \
static DEVICE_ATTR(_name, S_IRUGO, cxacru_sysfs_show_##_name, NULL)

#define CXACRU_CMD_INIT(_name) \
static DEVICE_ATTR(_name, S_IWUSR | S_IRUGO, \
cxacru_sysfs_show_##_name, cxacru_sysfs_store_##_name)

#define CXACRU_ATTR_INIT(_value, _type, _name) \
static ssize_t cxacru_sysfs_show_##_name(struct device *dev, \
struct device_attribute *attr, char *buf) \
Expand All @@ -187,9 +207,11 @@ static ssize_t cxacru_sysfs_show_##_name(struct device *dev, \
CXACRU__ATTR_INIT(_name)

#define CXACRU_ATTR_CREATE(_v, _t, _name) CXACRU_DEVICE_CREATE_FILE(_name)
#define CXACRU_CMD_CREATE(_name) CXACRU_DEVICE_CREATE_FILE(_name)
#define CXACRU__ATTR_CREATE(_name) CXACRU_DEVICE_CREATE_FILE(_name)

#define CXACRU_ATTR_REMOVE(_v, _t, _name) CXACRU_DEVICE_REMOVE_FILE(_name)
#define CXACRU_CMD_REMOVE(_name) CXACRU_DEVICE_REMOVE_FILE(_name)
#define CXACRU__ATTR_REMOVE(_name) CXACRU_DEVICE_REMOVE_FILE(_name)

static ssize_t cxacru_sysfs_showattr_u32(u32 value, char *buf)
Expand Down Expand Up @@ -278,6 +300,119 @@ static ssize_t cxacru_sysfs_show_mac_address(struct device *dev,
atm_dev->esi[3], atm_dev->esi[4], atm_dev->esi[5]);
}

static ssize_t cxacru_sysfs_show_adsl_state(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct usb_interface *intf = to_usb_interface(dev);
struct usbatm_data *usbatm_instance = usb_get_intfdata(intf);
struct cxacru_data *instance = usbatm_instance->driver_data;
u32 value = instance->card_info[CXINF_LINE_STARTABLE];

switch (value) {
case 0: return snprintf(buf, PAGE_SIZE, "running\n");
case 1: return snprintf(buf, PAGE_SIZE, "stopped\n");
default: return snprintf(buf, PAGE_SIZE, "unknown (%u)\n", value);
}
}

static ssize_t cxacru_sysfs_store_adsl_state(struct device *dev,
struct device_attribute *attr, const char *buf, size_t count)
{
struct usb_interface *intf = to_usb_interface(dev);
struct usbatm_data *usbatm_instance = usb_get_intfdata(intf);
struct cxacru_data *instance = usbatm_instance->driver_data;
int ret;
int poll = -1;
char str_cmd[8];
int len = strlen(buf);

if (!capable(CAP_NET_ADMIN))
return -EACCES;

ret = sscanf(buf, "%7s", str_cmd);
if (ret != 1)
return -EINVAL;
ret = 0;

if (mutex_lock_interruptible(&instance->adsl_state_serialize))
return -ERESTARTSYS;

if (!strcmp(str_cmd, "stop") || !strcmp(str_cmd, "restart")) {
ret = cxacru_cm(instance, CM_REQUEST_CHIP_ADSL_LINE_STOP, NULL, 0, NULL, 0);
if (ret < 0) {
atm_err(usbatm_instance, "change adsl state:"
" CHIP_ADSL_LINE_STOP returned %d\n", ret);

ret = -EIO;
} else {
ret = len;
poll = CXPOLL_STOPPED;
}
}

/* Line status is only updated every second
* and the device appears to only react to
* START/STOP every second too. Wait 1.5s to
* be sure that restart will have an effect. */
if (!strcmp(str_cmd, "restart"))
msleep(1500);

if (!strcmp(str_cmd, "start") || !strcmp(str_cmd, "restart")) {
ret = cxacru_cm(instance, CM_REQUEST_CHIP_ADSL_LINE_START, NULL, 0, NULL, 0);
if (ret < 0) {
atm_err(usbatm_instance, "change adsl state:"
" CHIP_ADSL_LINE_START returned %d\n", ret);

ret = -EIO;
} else {
ret = len;
poll = CXPOLL_POLLING;
}
}

if (!strcmp(str_cmd, "poll")) {
ret = len;
poll = CXPOLL_POLLING;
}

if (ret == 0) {
ret = -EINVAL;
poll = -1;
}

if (poll == CXPOLL_POLLING) {
mutex_lock(&instance->poll_state_serialize);
switch (instance->poll_state) {
case CXPOLL_STOPPED:
/* start polling */
instance->poll_state = CXPOLL_POLLING;
break;

case CXPOLL_STOPPING:
/* abort stop request */
instance->poll_state = CXPOLL_POLLING;
case CXPOLL_POLLING:
case CXPOLL_SHUTDOWN:
/* don't start polling */
poll = -1;
}
mutex_unlock(&instance->poll_state_serialize);
} else if (poll == CXPOLL_STOPPED) {
mutex_lock(&instance->poll_state_serialize);
/* request stop */
if (instance->poll_state == CXPOLL_POLLING)
instance->poll_state = CXPOLL_STOPPING;
mutex_unlock(&instance->poll_state_serialize);
}

mutex_unlock(&instance->adsl_state_serialize);

if (poll == CXPOLL_POLLING)
cxacru_poll_status(&instance->poll_work.work);

return ret;
}

/*
* All device attributes are included in CXACRU_ALL_FILES
* so that the same list can be used multiple times:
Expand Down Expand Up @@ -312,7 +447,8 @@ CXACRU_ATTR_##_action(CXINF_LINE_STARTABLE, bool, line_startable); \
CXACRU_ATTR_##_action(CXINF_MODULATION, MODU, modulation); \
CXACRU_ATTR_##_action(CXINF_ADSL_HEADEND, u32, adsl_headend); \
CXACRU_ATTR_##_action(CXINF_ADSL_HEADEND_ENVIRONMENT, u32, adsl_headend_environment); \
CXACRU_ATTR_##_action(CXINF_CONTROLLER_VERSION, u32, adsl_controller_version);
CXACRU_ATTR_##_action(CXINF_CONTROLLER_VERSION, u32, adsl_controller_version); \
CXACRU_CMD_##_action( adsl_state);

CXACRU_ALL_FILES(INIT);

Expand Down Expand Up @@ -493,8 +629,6 @@ static int cxacru_card_status(struct cxacru_data *instance)
return 0;
}

static void cxacru_poll_status(struct work_struct *work);

static int cxacru_atm_start(struct usbatm_data *usbatm_instance,
struct atm_dev *atm_dev)
{
Expand All @@ -503,6 +637,7 @@ static int cxacru_atm_start(struct usbatm_data *usbatm_instance,
struct atm_dev *atm_dev = usbatm_instance->atm_dev;
*/
int ret;
int start_polling = 1;

dbg("cxacru_atm_start");

Expand All @@ -515,14 +650,35 @@ static int cxacru_atm_start(struct usbatm_data *usbatm_instance,
}

/* start ADSL */
mutex_lock(&instance->adsl_state_serialize);
ret = cxacru_cm(instance, CM_REQUEST_CHIP_ADSL_LINE_START, NULL, 0, NULL, 0);
if (ret < 0) {
atm_err(usbatm_instance, "cxacru_atm_start: CHIP_ADSL_LINE_START returned %d\n", ret);
mutex_unlock(&instance->adsl_state_serialize);
return ret;
}

/* Start status polling */
cxacru_poll_status(&instance->poll_work.work);
mutex_lock(&instance->poll_state_serialize);
switch (instance->poll_state) {
case CXPOLL_STOPPED:
/* start polling */
instance->poll_state = CXPOLL_POLLING;
break;

case CXPOLL_STOPPING:
/* abort stop request */
instance->poll_state = CXPOLL_POLLING;
case CXPOLL_POLLING:
case CXPOLL_SHUTDOWN:
/* don't start polling */
start_polling = 0;
}
mutex_unlock(&instance->poll_state_serialize);
mutex_unlock(&instance->adsl_state_serialize);

if (start_polling)
cxacru_poll_status(&instance->poll_work.work);
return 0;
}

Expand All @@ -533,16 +689,46 @@ static void cxacru_poll_status(struct work_struct *work)
u32 buf[CXINF_MAX] = {};
struct usbatm_data *usbatm = instance->usbatm;
struct atm_dev *atm_dev = usbatm->atm_dev;
int keep_polling = 1;
int ret;

ret = cxacru_cm_get_array(instance, CM_REQUEST_CARD_INFO_GET, buf, CXINF_MAX);
if (ret < 0) {
atm_warn(usbatm, "poll status: error %d\n", ret);
if (ret != -ESHUTDOWN)
atm_warn(usbatm, "poll status: error %d\n", ret);

mutex_lock(&instance->poll_state_serialize);
if (instance->poll_state != CXPOLL_SHUTDOWN) {
instance->poll_state = CXPOLL_STOPPED;

if (ret != -ESHUTDOWN)
atm_warn(usbatm, "polling disabled, set adsl_state"
" to 'start' or 'poll' to resume\n");
}
mutex_unlock(&instance->poll_state_serialize);
goto reschedule;
}

memcpy(instance->card_info, buf, sizeof(instance->card_info));

if (instance->adsl_status != buf[CXINF_LINE_STARTABLE]) {
instance->adsl_status = buf[CXINF_LINE_STARTABLE];

switch (instance->adsl_status) {
case 0:
atm_printk(KERN_INFO, usbatm, "ADSL state: running\n");
break;

case 1:
atm_printk(KERN_INFO, usbatm, "ADSL state: stopped\n");
break;

default:
atm_printk(KERN_INFO, usbatm, "Unknown adsl status %02x\n", instance->adsl_status);
break;
}
}

if (instance->line_status == buf[CXINF_LINE_STATUS])
goto reschedule;

Expand Down Expand Up @@ -597,8 +783,20 @@ static void cxacru_poll_status(struct work_struct *work)
break;
}
reschedule:
schedule_delayed_work(&instance->poll_work,
round_jiffies_relative(msecs_to_jiffies(POLL_INTERVAL*1000)));

mutex_lock(&instance->poll_state_serialize);
if (instance->poll_state == CXPOLL_STOPPING &&
instance->adsl_status == 1 && /* stopped */
instance->line_status == 0) /* down */
instance->poll_state = CXPOLL_STOPPED;

if (instance->poll_state == CXPOLL_STOPPED)
keep_polling = 0;
mutex_unlock(&instance->poll_state_serialize);

if (keep_polling)
schedule_delayed_work(&instance->poll_work,
round_jiffies_relative(POLL_INTERVAL*HZ));
}

static int cxacru_fw(struct usb_device *usb_dev, enum cxacru_fw_request fw,
Expand Down Expand Up @@ -835,6 +1033,13 @@ static int cxacru_bind(struct usbatm_data *usbatm_instance,
instance->modem_type = (struct cxacru_modem_type *) id->driver_info;
memset(instance->card_info, 0, sizeof(instance->card_info));

mutex_init(&instance->poll_state_serialize);
instance->poll_state = CXPOLL_STOPPED;
instance->line_status = -1;
instance->adsl_status = -1;

mutex_init(&instance->adsl_state_serialize);

instance->rcv_buf = (u8 *) __get_free_page(GFP_KERNEL);
if (!instance->rcv_buf) {
dbg("cxacru_bind: no memory for rcv_buf");
Expand Down Expand Up @@ -909,6 +1114,7 @@ static void cxacru_unbind(struct usbatm_data *usbatm_instance,
struct usb_interface *intf)
{
struct cxacru_data *instance = usbatm_instance->driver_data;
int is_polling = 1;

dbg("cxacru_unbind entered");

Expand All @@ -917,8 +1123,20 @@ static void cxacru_unbind(struct usbatm_data *usbatm_instance,
return;
}

while (!cancel_delayed_work(&instance->poll_work))
flush_scheduled_work();
mutex_lock(&instance->poll_state_serialize);
BUG_ON(instance->poll_state == CXPOLL_SHUTDOWN);

/* ensure that status polling continues unless
* it has already stopped */
if (instance->poll_state == CXPOLL_STOPPED)
is_polling = 0;

/* stop polling from being stopped or started */
instance->poll_state = CXPOLL_SHUTDOWN;
mutex_unlock(&instance->poll_state_serialize);

if (is_polling)
cancel_rearming_delayed_work(&instance->poll_work);

usb_kill_urb(instance->snd_urb);
usb_kill_urb(instance->rcv_urb);
Expand Down

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