From: Emmanuel Grumbach <emmanuel.grumbach@xxxxxxxxx>
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: Emmanuel Grumbach <emmanuel.grumbach@xxxxxxxxx>
Signed-off-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
---
drivers/net/wireless/iwlwifi/iwl-agn.c | 318 ++++++++++++++++----------------
1 files changed, 159 insertions(+), 159 deletions(-)
diff --git a/drivers/net/wireless/iwlwifi/iwl-agn.c b/drivers/net/wireless/iwlwifi/iwl-agn.c
index aef4f71..7726e67 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn.c
@@ -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);
@@ -3264,141 +3421,6 @@ static int iwlagn_mac_sta_add(struct ieee80211_hw *hw,
/*****************************************************************************
*
- * 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:
--
1.7.0.4
--
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