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Commit 7d47618a authored by Emmanuel Grumbach's avatar Emmanuel Grumbach Committed by Reinette Chatre
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iwlwifi: move sysfs_create_group to post request firmware 

Move the sysfs_create_group to iwl_ucode_callback after we
have safely got the firmware.

The motivation to do this comes from a warning from lockdep which detected
that we request priv->mutex while holding s_active during a sysfs request
(show_statistics in the example copy pasted). The reverse order exists upon
request_firmware: request_firmware which is a sysfs operation
that requires s_active is run under priv->mutex.

This ensures that we don't get sysfs request before we finish to request
the firmware, avoiding this deadlock.

=======================================================
[ INFO: possible circular locking dependency detected ]
-------------------------------------------------------
cat/2595 is trying to acquire lock:
 (&priv->mutex){+.+.+.}, at: [<facfa598>] show_statistics+0x48/0x100 [iwlagn]

but task is already holding lock:
 (s_active){++++.+}, at: [<c0580ebd>] sysfs_get_active_two+0x1d/0x50

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (s_active){++++.+}:
       [<c0489b74>] __lock_acquire+0xc44/0x1230
       [<c048a1ed>] lock_acquire+0x8d/0x110
       [<c0581499>] sysfs_addrm_finish+0xe9/0x180
       [<c057f64a>] sysfs_hash_and_remove+0x4a/0x80
       [<c05829d4>] sysfs_remove_group+0x44/0xd0
       [<c0714b75>] dpm_sysfs_remove+0x15/0x20
       [<c070dac8>] device_del+0x38/0x170
       [<c070dc1e>] device_unregister+0x1e/0x60
       [<c071838d>] _request_firmware+0x29d/0x550
       [<c07186c7>] request_firmware+0x17/0x20
       [<fad01bf1>] iwl_mac_start+0xb1/0x1230 [iwlagn]
       [<fa46ba06>] ieee80211_open+0x436/0x6f0 [mac80211]
       [<c0808cd2>] dev_open+0x92/0xf0
       [<c0808b2b>] dev_change_flags+0x7b/0x190
       [<c08148e8>] do_setlink+0x178/0x3b0
       [<c0815169>] rtnl_setlink+0xf9/0x130
       [<c081453b>] rtnetlink_rcv_msg+0x1bb/0x1f0
       [<c0827ce6>] netlink_rcv_skb+0x86/0xa0
       [<c081436c>] rtnetlink_rcv+0x1c/0x30
       [<c08279c3>] netlink_unicast+0x263/0x290
       [<c0828768>] netlink_sendmsg+0x1c8/0x2a0
       [<c07f85fd>] sock_sendmsg+0xcd/0x100
       [<c07f964d>] sys_sendmsg+0x15d/0x290
       [<c07f9e6b>] sys_socketcall+0xeb/0x2a0
       [<c040ad9f>] sysenter_do_call+0x12/0x38

-> #0 (&priv->mutex){+.+.+.}:
       [<c0489f84>] __lock_acquire+0x1054/0x1230
       [<c048a1ed>] lock_acquire+0x8d/0x110
       [<c08bb358>] __mutex_lock_common+0x58/0x470
       [<c08bb84a>] mutex_lock_nested+0x3a/0x50
       [<facfa598>] show_statistics+0x48/0x100 [iwlagn]
       [<c070d219>] dev_attr_show+0x29/0x50
       [<c057fecd>] sysfs_read_file+0xdd/0x190
       [<c052880f>] vfs_read+0x9f/0x190
       [<c0528d22>] sys_read+0x42/0x70
       [<c040ad9f>] sysenter_do_call+0x12/0x38

other info that might help us debug this:

3 locks held by cat/2595:
 #0:  (&buffer->mutex){+.+.+.}, at: [<c057fe25>] sysfs_read_file+0x35/0x190
 #1:  (s_active){++++.+}, at: [<c0580ecd>] sysfs_get_active_two+0x2d/0x50
 #2:  (s_active){++++.+}, at: [<c0580ebd>] sysfs_get_active_two+0x1d/0x50

stack backtrace:
Pid: 2595, comm: cat Not tainted 2.6.33-tp-rc4 #2
Call Trace:
 [<c08b99ab>] ? printk+0x1d/0x22
 [<c0487752>] print_circular_bug+0xc2/0xd0
 [<c0489f84>] __lock_acquire+0x1054/0x1230
 [<c0478d81>] ? sched_clock_cpu+0x121/0x180
 [<c048a1ed>] lock_acquire+0x8d/0x110
 [<facfa598>] ? show_statistics+0x48/0x100 [iwlagn]
 [<c08bb358>] __mutex_lock_common+0x58/0x470
 [<facfa598>] ? show_statistics+0x48/0x100 [iwlagn]
 [<c08bb84a>] mutex_lock_nested+0x3a/0x50
 [<facfa598>] ? show_statistics+0x48/0x100 [iwlagn]
 [<facfa598>] show_statistics+0x48/0x100 [iwlagn]
 [<c0580cf9>] ? sysfs_get_active+0x69/0xb0
 [<facfa550>] ? show_statistics+0x0/0x100 [iwlagn]
 [<c070d219>] dev_attr_show+0x29/0x50
 [<c057fecd>] sysfs_read_file+0xdd/0x190
 [<c05ff314>] ? security_file_permission+0x14/0x20
 [<c0528242>] ? rw_verify_area+0x62/0xd0
 [<c052880f>] vfs_read+0x9f/0x190
 [<c047745b>] ? up_read+0x1b/0x30
 [<c057fdf0>] ? sysfs_read_file+0x0/0x190
 [<c04af3b4>] ? audit_syscall_entry+0x1f4/0x220
 [<c0528d22>] sys_read+0x42/0x70
 [<c040ad9f>] sysenter_do_call+0x12/0x38
Signed-off-by: default avatarEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: default avatarReinette Chatre <reinette.chatre@intel.com>
parent 9edc71b7
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Inline Side-by-side
Showing with 159 additions and 159 deletions
drivers/net/wireless/iwlwifi/iwl-agn.c
View file @ 7d47618a
......@@ -1484,6 +1484,156 @@ bool iwl_good_ack_health(struct iwl_priv *priv,
}
/*****************************************************************************
*
* sysfs attributes
*
*****************************************************************************/
#ifdef CONFIG_IWLWIFI_DEBUG
/*
* The following adds a new attribute to the sysfs representation
* of this device driver (i.e. a new file in /sys/class/net/wlan0/device/)
* used for controlling the debug level.
*
* See the level definitions in iwl for details.
*
* The debug_level being managed using sysfs below is a per device debug
* level that is used instead of the global debug level if it (the per
* device debug level) is set.
*/
static ssize_t show_debug_level(struct device *d,
struct device_attribute *attr, char *buf)
{
struct iwl_priv *priv = dev_get_drvdata(d);
return sprintf(buf, "0x%08X\n", iwl_get_debug_level(priv));
}
static ssize_t store_debug_level(struct device *d,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct iwl_priv *priv = dev_get_drvdata(d);
unsigned long val;
int ret;
ret = strict_strtoul(buf, 0, &val);
if (ret)
IWL_ERR(priv, "%s is not in hex or decimal form.\n", buf);
else {
priv->debug_level = val;
if (iwl_alloc_traffic_mem(priv))
IWL_ERR(priv,
"Not enough memory to generate traffic log\n");
}
return strnlen(buf, count);
}
static DEVICE_ATTR(debug_level, S_IWUSR | S_IRUGO,
show_debug_level, store_debug_level);
#endif /* CONFIG_IWLWIFI_DEBUG */
static ssize_t show_temperature(struct device *d,
struct device_attribute *attr, char *buf)
{
struct iwl_priv *priv = dev_get_drvdata(d);
if (!iwl_is_alive(priv))
return -EAGAIN;
return sprintf(buf, "%d\n", priv->temperature);
}
static DEVICE_ATTR(temperature, S_IRUGO, show_temperature, NULL);
static ssize_t show_tx_power(struct device *d,
struct device_attribute *attr, char *buf)
{
struct iwl_priv *priv = dev_get_drvdata(d);
if (!iwl_is_ready_rf(priv))
return sprintf(buf, "off\n");
else
return sprintf(buf, "%d\n", priv->tx_power_user_lmt);
}
static ssize_t store_tx_power(struct device *d,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct iwl_priv *priv = dev_get_drvdata(d);
unsigned long val;
int ret;
ret = strict_strtoul(buf, 10, &val);
if (ret)
IWL_INFO(priv, "%s is not in decimal form.\n", buf);
else {
ret = iwl_set_tx_power(priv, val, false);
if (ret)
IWL_ERR(priv, "failed setting tx power (0x%d).\n",
ret);
else
ret = count;
}
return ret;
}
static DEVICE_ATTR(tx_power, S_IWUSR | S_IRUGO, show_tx_power, store_tx_power);
static ssize_t show_rts_ht_protection(struct device *d,
struct device_attribute *attr, char *buf)
{
struct iwl_priv *priv = dev_get_drvdata(d);
return sprintf(buf, "%s\n",
priv->cfg->use_rts_for_ht ? "RTS/CTS" : "CTS-to-self");
}
static ssize_t store_rts_ht_protection(struct device *d,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct iwl_priv *priv = dev_get_drvdata(d);
unsigned long val;
int ret;
ret = strict_strtoul(buf, 10, &val);
if (ret)
IWL_INFO(priv, "Input is not in decimal form.\n");
else {
if (!iwl_is_associated(priv))
priv->cfg->use_rts_for_ht = val ? true : false;
else
IWL_ERR(priv, "Sta associated with AP - "
"Change protection mechanism is not allowed\n");
ret = count;
}
return ret;
}
static DEVICE_ATTR(rts_ht_protection, S_IWUSR | S_IRUGO,
show_rts_ht_protection, store_rts_ht_protection);
static struct attribute *iwl_sysfs_entries[] = {
&dev_attr_temperature.attr,
&dev_attr_tx_power.attr,
&dev_attr_rts_ht_protection.attr,
#ifdef CONFIG_IWLWIFI_DEBUG
&dev_attr_debug_level.attr,
#endif
NULL
};
static struct attribute_group iwl_attribute_group = {
.name = NULL, /* put in device directory */
.attrs = iwl_sysfs_entries,
};
/******************************************************************************
*
* uCode download functions
......@@ -1965,6 +2115,13 @@ static void iwl_ucode_callback(const struct firmware *ucode_raw, void *context)
if (err)
IWL_ERR(priv, "failed to create debugfs files. Ignoring error: %d\n", err);
err = sysfs_create_group(&priv->pci_dev->dev.kobj,
&iwl_attribute_group);
if (err) {
IWL_ERR(priv, "failed to create sysfs device attributes\n");
goto out_unbind;
}
/* We have our copies now, allow OS release its copies */
release_firmware(ucode_raw);
complete(&priv->_agn.firmware_loading_complete);
......@@ -3262,141 +3419,6 @@ static int iwlagn_mac_sta_add(struct ieee80211_hw *hw,
return 0;
}
/*****************************************************************************
*
* sysfs attributes
*
*****************************************************************************/
#ifdef CONFIG_IWLWIFI_DEBUG
/*
* The following adds a new attribute to the sysfs representation
* of this device driver (i.e. a new file in /sys/class/net/wlan0/device/)
* used for controlling the debug level.
*
* See the level definitions in iwl for details.
*
* The debug_level being managed using sysfs below is a per device debug
* level that is used instead of the global debug level if it (the per
* device debug level) is set.
*/
static ssize_t show_debug_level(struct device *d,
struct device_attribute *attr, char *buf)
{
struct iwl_priv *priv = dev_get_drvdata(d);
return sprintf(buf, "0x%08X\n", iwl_get_debug_level(priv));
}
static ssize_t store_debug_level(struct device *d,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct iwl_priv *priv = dev_get_drvdata(d);
unsigned long val;
int ret;
ret = strict_strtoul(buf, 0, &val);
if (ret)
IWL_ERR(priv, "%s is not in hex or decimal form.\n", buf);
else {
priv->debug_level = val;
if (iwl_alloc_traffic_mem(priv))
IWL_ERR(priv,
"Not enough memory to generate traffic log\n");
}
return strnlen(buf, count);
}
static DEVICE_ATTR(debug_level, S_IWUSR | S_IRUGO,
show_debug_level, store_debug_level);
#endif /* CONFIG_IWLWIFI_DEBUG */
static ssize_t show_temperature(struct device *d,
struct device_attribute *attr, char *buf)
{
struct iwl_priv *priv = dev_get_drvdata(d);
if (!iwl_is_alive(priv))
return -EAGAIN;
return sprintf(buf, "%d\n", priv->temperature);
}
static DEVICE_ATTR(temperature, S_IRUGO, show_temperature, NULL);
static ssize_t show_tx_power(struct device *d,
struct device_attribute *attr, char *buf)
{
struct iwl_priv *priv = dev_get_drvdata(d);
if (!iwl_is_ready_rf(priv))
return sprintf(buf, "off\n");
else
return sprintf(buf, "%d\n", priv->tx_power_user_lmt);
}
static ssize_t store_tx_power(struct device *d,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct iwl_priv *priv = dev_get_drvdata(d);
unsigned long val;
int ret;
ret = strict_strtoul(buf, 10, &val);
if (ret)
IWL_INFO(priv, "%s is not in decimal form.\n", buf);
else {
ret = iwl_set_tx_power(priv, val, false);
if (ret)
IWL_ERR(priv, "failed setting tx power (0x%d).\n",
ret);
else
ret = count;
}
return ret;
}
static DEVICE_ATTR(tx_power, S_IWUSR | S_IRUGO, show_tx_power, store_tx_power);
static ssize_t show_rts_ht_protection(struct device *d,
struct device_attribute *attr, char *buf)
{
struct iwl_priv *priv = dev_get_drvdata(d);
return sprintf(buf, "%s\n",
priv->cfg->use_rts_for_ht ? "RTS/CTS" : "CTS-to-self");
}
static ssize_t store_rts_ht_protection(struct device *d,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct iwl_priv *priv = dev_get_drvdata(d);
unsigned long val;
int ret;
ret = strict_strtoul(buf, 10, &val);
if (ret)
IWL_INFO(priv, "Input is not in decimal form.\n");
else {
if (!iwl_is_associated(priv))
priv->cfg->use_rts_for_ht = val ? true : false;
else
IWL_ERR(priv, "Sta associated with AP - "
"Change protection mechanism is not allowed\n");
ret = count;
}
return ret;
}
static DEVICE_ATTR(rts_ht_protection, S_IWUSR | S_IRUGO,
show_rts_ht_protection, store_rts_ht_protection);
/*****************************************************************************
*
* driver setup and teardown
......@@ -3550,21 +3572,6 @@ static void iwl_uninit_drv(struct iwl_priv *priv)
kfree(priv->scan_cmd);
}
static struct attribute *iwl_sysfs_entries[] = {
&dev_attr_temperature.attr,
&dev_attr_tx_power.attr,
&dev_attr_rts_ht_protection.attr,
#ifdef CONFIG_IWLWIFI_DEBUG
&dev_attr_debug_level.attr,
#endif
NULL
};
static struct attribute_group iwl_attribute_group = {
.name = NULL, /* put in device directory */
.attrs = iwl_sysfs_entries,
};
static struct ieee80211_ops iwl_hw_ops = {
.tx = iwl_mac_tx,
.start = iwl_mac_start,
......@@ -3750,11 +3757,6 @@ static int iwl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
IWL_ERR(priv, "Error allocating IRQ %d\n", priv->pci_dev->irq);
goto out_disable_msi;
}
err = sysfs_create_group(&pdev->dev.kobj, &iwl_attribute_group);
if (err) {
IWL_ERR(priv, "failed to create sysfs device attributes\n");
goto out_free_irq;
}
iwl_setup_deferred_work(priv);
iwl_setup_rx_handlers(priv);
......@@ -3788,15 +3790,13 @@ static int iwl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
err = iwl_request_firmware(priv, true);
if (err)
goto out_remove_sysfs;
goto out_destroy_workqueue;
return 0;
out_remove_sysfs:
out_destroy_workqueue:
destroy_workqueue(priv->workqueue);
priv->workqueue = NULL;
sysfs_remove_group(&pdev->dev.kobj, &iwl_attribute_group);
out_free_irq:
free_irq(priv->pci_dev->irq, priv);
iwl_free_isr_ict(priv);
out_disable_msi:
......
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