From 7d47618a2ade0cb6d8a0b2597029c383c1662fa0 Mon Sep 17 00:00:00 2001 From: Emmanuel Grumbach Date: Sun, 23 May 2010 00:14:08 -0700 Subject: [PATCH] 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: [] show_statistics+0x48/0x100 [iwlagn] but task is already holding lock: (s_active){++++.+}, at: [] 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){++++.+}: [] __lock_acquire+0xc44/0x1230 [] lock_acquire+0x8d/0x110 [] sysfs_addrm_finish+0xe9/0x180 [] sysfs_hash_and_remove+0x4a/0x80 [] sysfs_remove_group+0x44/0xd0 [] dpm_sysfs_remove+0x15/0x20 [] device_del+0x38/0x170 [] device_unregister+0x1e/0x60 [] _request_firmware+0x29d/0x550 [] request_firmware+0x17/0x20 [] iwl_mac_start+0xb1/0x1230 [iwlagn] [] ieee80211_open+0x436/0x6f0 [mac80211] [] dev_open+0x92/0xf0 [] dev_change_flags+0x7b/0x190 [] do_setlink+0x178/0x3b0 [] rtnl_setlink+0xf9/0x130 [] rtnetlink_rcv_msg+0x1bb/0x1f0 [] netlink_rcv_skb+0x86/0xa0 [] rtnetlink_rcv+0x1c/0x30 [] netlink_unicast+0x263/0x290 [] netlink_sendmsg+0x1c8/0x2a0 [] sock_sendmsg+0xcd/0x100 [] sys_sendmsg+0x15d/0x290 [] sys_socketcall+0xeb/0x2a0 [] sysenter_do_call+0x12/0x38 -> #0 (&priv->mutex){+.+.+.}: [] __lock_acquire+0x1054/0x1230 [] lock_acquire+0x8d/0x110 [] __mutex_lock_common+0x58/0x470 [] mutex_lock_nested+0x3a/0x50 [] show_statistics+0x48/0x100 [iwlagn] [] dev_attr_show+0x29/0x50 [] sysfs_read_file+0xdd/0x190 [] vfs_read+0x9f/0x190 [] sys_read+0x42/0x70 [] sysenter_do_call+0x12/0x38 other info that might help us debug this: 3 locks held by cat/2595: #0: (&buffer->mutex){+.+.+.}, at: [] sysfs_read_file+0x35/0x190 #1: (s_active){++++.+}, at: [] sysfs_get_active_two+0x2d/0x50 #2: (s_active){++++.+}, at: [] sysfs_get_active_two+0x1d/0x50 stack backtrace: Pid: 2595, comm: cat Not tainted 2.6.33-tp-rc4 #2 Call Trace: [] ? printk+0x1d/0x22 [] print_circular_bug+0xc2/0xd0 [] __lock_acquire+0x1054/0x1230 [] ? sched_clock_cpu+0x121/0x180 [] lock_acquire+0x8d/0x110 [] ? show_statistics+0x48/0x100 [iwlagn] [] __mutex_lock_common+0x58/0x470 [] ? show_statistics+0x48/0x100 [iwlagn] [] mutex_lock_nested+0x3a/0x50 [] ? show_statistics+0x48/0x100 [iwlagn] [] show_statistics+0x48/0x100 [iwlagn] [] ? sysfs_get_active+0x69/0xb0 [] ? show_statistics+0x0/0x100 [iwlagn] [] dev_attr_show+0x29/0x50 [] sysfs_read_file+0xdd/0x190 [] ? security_file_permission+0x14/0x20 [] ? rw_verify_area+0x62/0xd0 [] vfs_read+0x9f/0x190 [] ? up_read+0x1b/0x30 [] ? sysfs_read_file+0x0/0x190 [] ? audit_syscall_entry+0x1f4/0x220 [] sys_read+0x42/0x70 [] sysenter_do_call+0x12/0x38 Signed-off-by: Emmanuel Grumbach Signed-off-by: Reinette Chatre --- drivers/net/wireless/iwlwifi/iwl-agn.c | 318 ++++++++++++------------- 1 file changed, 159 insertions(+), 159 deletions(-) diff --git a/drivers/net/wireless/iwlwifi/iwl-agn.c b/drivers/net/wireless/iwlwifi/iwl-agn.c index aef4f71f1981..7726e67044c0 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); @@ -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: -- 2.20.1