diff options
author | Dominik Brodowski <linux@dominikbrodowski.net> | 2010-01-17 18:13:31 +0100 |
---|---|---|
committer | Dominik Brodowski <linux@dominikbrodowski.net> | 2010-02-17 17:48:25 +0100 |
commit | f971dbd5da4e2fbf756d07b938a9c65a9c75178b (patch) | |
tree | d21b138ac2ea3ada0e27910425cfd988f72dbede | |
parent | pcmcia: use ops_mutex for rsrc_{mgr,nonstatic} locking (diff) | |
download | linux-f971dbd5da4e2fbf756d07b938a9c65a9c75178b.tar.xz linux-f971dbd5da4e2fbf756d07b938a9c65a9c75178b.zip |
pcmcia: use pccardd to handle eject, insert, suspend and resume requests
This avoids any sysfs-related deadlock (or lockdep warning), such
as reported at http://lkml.org/lkml/2010/1/17/88 .
Reported-by: Ming Lei <tom.leiming@gmail.com>
Tested-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
-rw-r--r-- | drivers/pcmcia/cs.c | 177 | ||||
-rw-r--r-- | drivers/pcmcia/cs_internal.h | 10 | ||||
-rw-r--r-- | drivers/pcmcia/pcmcia_ioctl.c | 8 | ||||
-rw-r--r-- | drivers/pcmcia/socket_sysfs.c | 26 | ||||
-rw-r--r-- | include/pcmcia/ss.h | 3 |
5 files changed, 83 insertions, 141 deletions
diff --git a/drivers/pcmcia/cs.c b/drivers/pcmcia/cs.c index 7ba45b0cca6b..823ecda32216 100644 --- a/drivers/pcmcia/cs.c +++ b/drivers/pcmcia/cs.c @@ -505,7 +505,10 @@ static int socket_insert(struct pcmcia_socket *skt) dev_dbg(&skt->dev, "insert\n"); mutex_lock(&skt->ops_mutex); - WARN_ON(skt->state & SOCKET_INUSE); + if (skt->state & SOCKET_INUSE) { + mutex_unlock(&skt->ops_mutex); + return -EINVAL; + } skt->state |= SOCKET_INUSE; ret = socket_setup(skt, setup_delay); @@ -682,16 +685,19 @@ static int pccardd(void *__skt) for (;;) { unsigned long flags; unsigned int events; + unsigned int sysfs_events; set_current_state(TASK_INTERRUPTIBLE); spin_lock_irqsave(&skt->thread_lock, flags); events = skt->thread_events; skt->thread_events = 0; + sysfs_events = skt->sysfs_events; + skt->sysfs_events = 0; spin_unlock_irqrestore(&skt->thread_lock, flags); + mutex_lock(&skt->skt_mutex); if (events) { - mutex_lock(&skt->skt_mutex); if (events & SS_DETECT) socket_detect_change(skt); if (events & SS_BATDEAD) @@ -700,10 +706,34 @@ static int pccardd(void *__skt) send_event(skt, CS_EVENT_BATTERY_LOW, CS_EVENT_PRI_LOW); if (events & SS_READY) send_event(skt, CS_EVENT_READY_CHANGE, CS_EVENT_PRI_LOW); - mutex_unlock(&skt->skt_mutex); - continue; } + if (sysfs_events) { + if (sysfs_events & PCMCIA_UEVENT_EJECT) + socket_remove(skt); + if (sysfs_events & PCMCIA_UEVENT_INSERT) + socket_insert(skt); + if ((sysfs_events & PCMCIA_UEVENT_RESUME) && + !(skt->state & SOCKET_CARDBUS)) { + ret = socket_resume(skt); + if (!ret && skt->callback) + skt->callback->resume(skt); + } + if ((sysfs_events & PCMCIA_UEVENT_SUSPEND) && + !(skt->state & SOCKET_CARDBUS)) { + if (skt->callback) + ret = skt->callback->suspend(skt); + else + ret = 0; + if (!ret) + socket_suspend(skt); + } + } + mutex_unlock(&skt->skt_mutex); + + if (events || sysfs_events) + continue; + if (kthread_should_stop()) break; @@ -745,6 +775,30 @@ void pcmcia_parse_events(struct pcmcia_socket *s, u_int events) } /* pcmcia_parse_events */ EXPORT_SYMBOL(pcmcia_parse_events); +/** + * pcmcia_parse_uevents() - tell pccardd to issue manual commands + * @s: the PCMCIA socket we wan't to command + * @events: events to pass to pccardd + * + * userspace-issued insert, eject, suspend and resume commands must be + * handled by pccardd to avoid any sysfs-related deadlocks. Valid events + * are PCMCIA_UEVENT_EJECT (for eject), PCMCIA_UEVENT__INSERT (for insert), + * PCMCIA_UEVENT_RESUME (for resume) and PCMCIA_UEVENT_SUSPEND (for suspend). + */ +void pcmcia_parse_uevents(struct pcmcia_socket *s, u_int events) +{ + unsigned long flags; + dev_dbg(&s->dev, "parse_uevents: events %08x\n", events); + if (s->thread) { + spin_lock_irqsave(&s->thread_lock, flags); + s->sysfs_events |= events; + spin_unlock_irqrestore(&s->thread_lock, flags); + + wake_up_process(s->thread); + } +} +EXPORT_SYMBOL(pcmcia_parse_uevents); + /* register pcmcia_callback */ int pccard_register_pcmcia(struct pcmcia_socket *s, struct pcmcia_callback *c) @@ -828,121 +882,6 @@ int pcmcia_reset_card(struct pcmcia_socket *skt) EXPORT_SYMBOL(pcmcia_reset_card); -/* These shut down or wake up a socket. They are sort of user - * initiated versions of the APM suspend and resume actions. - */ -int pcmcia_suspend_card(struct pcmcia_socket *skt) -{ - int ret; - - dev_dbg(&skt->dev, "suspending socket\n"); - - mutex_lock(&skt->skt_mutex); - do { - if (!(skt->state & SOCKET_PRESENT)) { - ret = -ENODEV; - break; - } - if (skt->state & SOCKET_CARDBUS) { - ret = -EPERM; - break; - } - if (skt->callback) { - ret = skt->callback->suspend(skt); - if (ret) - break; - } - ret = socket_suspend(skt); - } while (0); - mutex_unlock(&skt->skt_mutex); - - return ret; -} /* suspend_card */ -EXPORT_SYMBOL(pcmcia_suspend_card); - - -int pcmcia_resume_card(struct pcmcia_socket *skt) -{ - int ret; - - dev_dbg(&skt->dev, "waking up socket\n"); - - mutex_lock(&skt->skt_mutex); - do { - if (!(skt->state & SOCKET_PRESENT)) { - ret = -ENODEV; - break; - } - if (skt->state & SOCKET_CARDBUS) { - ret = -EPERM; - break; - } - ret = socket_resume(skt); - if (!ret && skt->callback) - skt->callback->resume(skt); - } while (0); - mutex_unlock(&skt->skt_mutex); - - return ret; -} /* resume_card */ -EXPORT_SYMBOL(pcmcia_resume_card); - - -/* These handle user requests to eject or insert a card. */ -int pcmcia_eject_card(struct pcmcia_socket *skt) -{ - int ret; - - dev_dbg(&skt->dev, "user eject request\n"); - - mutex_lock(&skt->skt_mutex); - do { - if (!(skt->state & SOCKET_PRESENT)) { - ret = -ENODEV; - break; - } - - ret = send_event(skt, CS_EVENT_EJECTION_REQUEST, CS_EVENT_PRI_LOW); - if (ret != 0) { - ret = -EINVAL; - break; - } - - socket_remove(skt); - ret = 0; - } while (0); - mutex_unlock(&skt->skt_mutex); - - return ret; -} /* eject_card */ -EXPORT_SYMBOL(pcmcia_eject_card); - - -int pcmcia_insert_card(struct pcmcia_socket *skt) -{ - int ret; - - dev_dbg(&skt->dev, "user insert request\n"); - - mutex_lock(&skt->skt_mutex); - do { - if (skt->state & SOCKET_PRESENT) { - ret = -EBUSY; - break; - } - if (socket_insert(skt) == -ENODEV) { - ret = -ENODEV; - break; - } - ret = 0; - } while (0); - mutex_unlock(&skt->skt_mutex); - - return ret; -} /* insert_card */ -EXPORT_SYMBOL(pcmcia_insert_card); - - static int pcmcia_socket_uevent(struct device *dev, struct kobj_uevent_env *env) { diff --git a/drivers/pcmcia/cs_internal.h b/drivers/pcmcia/cs_internal.h index bd386d77845e..127c97acf849 100644 --- a/drivers/pcmcia/cs_internal.h +++ b/drivers/pcmcia/cs_internal.h @@ -124,11 +124,11 @@ extern struct class pcmcia_socket_class; int pccard_register_pcmcia(struct pcmcia_socket *s, struct pcmcia_callback *c); struct pcmcia_socket *pcmcia_get_socket_by_nr(unsigned int nr); -int pcmcia_suspend_card(struct pcmcia_socket *skt); -int pcmcia_resume_card(struct pcmcia_socket *skt); - -int pcmcia_eject_card(struct pcmcia_socket *skt); -int pcmcia_insert_card(struct pcmcia_socket *skt); +void pcmcia_parse_uevents(struct pcmcia_socket *socket, unsigned int events); +#define PCMCIA_UEVENT_EJECT 0x0001 +#define PCMCIA_UEVENT_INSERT 0x0002 +#define PCMCIA_UEVENT_SUSPEND 0x0004 +#define PCMCIA_UEVENT_RESUME 0x0008 struct pcmcia_socket *pcmcia_get_socket(struct pcmcia_socket *skt); void pcmcia_put_socket(struct pcmcia_socket *skt); diff --git a/drivers/pcmcia/pcmcia_ioctl.c b/drivers/pcmcia/pcmcia_ioctl.c index 96fd236f52a9..13a7132cf688 100644 --- a/drivers/pcmcia/pcmcia_ioctl.c +++ b/drivers/pcmcia/pcmcia_ioctl.c @@ -925,16 +925,16 @@ static int ds_ioctl(struct inode *inode, struct file *file, ret = pccard_validate_cis(s, &buf->cisinfo.Chains); break; case DS_SUSPEND_CARD: - ret = pcmcia_suspend_card(s); + pcmcia_parse_uevents(s, PCMCIA_UEVENT_SUSPEND); break; case DS_RESUME_CARD: - ret = pcmcia_resume_card(s); + pcmcia_parse_uevents(s, PCMCIA_UEVENT_RESUME); break; case DS_EJECT_CARD: - err = pcmcia_eject_card(s); + pcmcia_parse_uevents(s, PCMCIA_UEVENT_EJECT); break; case DS_INSERT_CARD: - err = pcmcia_insert_card(s); + pcmcia_parse_uevents(s, PCMCIA_UEVENT_INSERT); break; case DS_ACCESS_CONFIGURATION_REGISTER: if ((buf->conf_reg.Action == CS_WRITE) && !capable(CAP_SYS_ADMIN)) { diff --git a/drivers/pcmcia/socket_sysfs.c b/drivers/pcmcia/socket_sysfs.c index e8826df00a36..fba0e30183f4 100644 --- a/drivers/pcmcia/socket_sysfs.c +++ b/drivers/pcmcia/socket_sysfs.c @@ -88,15 +88,14 @@ static DEVICE_ATTR(card_vcc, 0444, pccard_show_vcc, NULL); static ssize_t pccard_store_insert(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { - ssize_t ret; struct pcmcia_socket *s = to_socket(dev); if (!count) return -EINVAL; - ret = pcmcia_insert_card(s); + pcmcia_parse_uevents(s, PCMCIA_UEVENT_INSERT); - return ret ? ret : count; + return count; } static DEVICE_ATTR(card_insert, 0200, NULL, pccard_store_insert); @@ -113,18 +112,22 @@ static ssize_t pccard_store_card_pm_state(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { - ssize_t ret = -EINVAL; struct pcmcia_socket *s = to_socket(dev); + ssize_t ret = count; if (!count) return -EINVAL; - if (!(s->state & SOCKET_SUSPEND) && !strncmp(buf, "off", 3)) - ret = pcmcia_suspend_card(s); - else if ((s->state & SOCKET_SUSPEND) && !strncmp(buf, "on", 2)) - ret = pcmcia_resume_card(s); + if (!strncmp(buf, "off", 3)) + pcmcia_parse_uevents(s, PCMCIA_UEVENT_SUSPEND); + else { + if (!strncmp(buf, "on", 2)) + pcmcia_parse_uevents(s, PCMCIA_UEVENT_RESUME); + else + ret = -EINVAL; + } - return ret ? -ENODEV : count; + return ret; } static DEVICE_ATTR(card_pm_state, 0644, pccard_show_card_pm_state, pccard_store_card_pm_state); @@ -132,15 +135,14 @@ static ssize_t pccard_store_eject(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { - ssize_t ret; struct pcmcia_socket *s = to_socket(dev); if (!count) return -EINVAL; - ret = pcmcia_eject_card(s); + pcmcia_parse_uevents(s, PCMCIA_UEVENT_EJECT); - return ret ? ret : count; + return count; } static DEVICE_ATTR(card_eject, 0200, NULL, pccard_store_eject); diff --git a/include/pcmcia/ss.h b/include/pcmcia/ss.h index cfaccc224b50..ea5dec8c0d76 100644 --- a/include/pcmcia/ss.h +++ b/include/pcmcia/ss.h @@ -200,13 +200,14 @@ struct pcmcia_socket { struct task_struct *thread; struct completion thread_done; unsigned int thread_events; + unsigned int sysfs_events; /* For the non-trivial interaction between these locks, * see Documentation/pcmcia/locking.txt */ struct mutex skt_mutex; struct mutex ops_mutex; - /* protects thread_events */ + /* protects thread_events and sysfs_events */ spinlock_t thread_lock; /* pcmcia (16-bit) */ |