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authorFranck Bui-Huu <vagabon.xyz@gmail.com>2006-06-14 10:29:21 +0200
committerGreg Kroah-Hartman <gregkh@suse.de>2006-06-21 15:04:17 -0700
commit943e1b4d60dc7acfabe2ebad31189bcb3b853688 (patch)
tree3a8de95902d0f8699d0c2dd1759a1841960d1720
parentb059c81af7a1759a911cfc20ce8a4bf47c435830 (diff)
[PATCH] USB: gadget-serial: fix a deadlock when closing the serial device
When closing the device, the driver acquires/release twice the port lock before/after waiting for the data to be completely sent. Therefore it will dead lock. This patch fixes it and also uses the generic scheduler services for waiting for an event. Signed-off-by: Franck Bui-Huu <vagabon.xyz@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--drivers/usb/gadget/serial.c95
1 files changed, 17 insertions, 78 deletions
diff --git a/drivers/usb/gadget/serial.c b/drivers/usb/gadget/serial.c
index b992546c394..b58f015554b 100644
--- a/drivers/usb/gadget/serial.c
+++ b/drivers/usb/gadget/serial.c
@@ -51,82 +51,10 @@
#include "gadget_chips.h"
-/* Wait Cond */
-
-#define __wait_cond_interruptible(wq, condition, lock, flags, ret) \
-do { \
- wait_queue_t __wait; \
- init_waitqueue_entry(&__wait, current); \
- \
- add_wait_queue(&wq, &__wait); \
- for (;;) { \
- set_current_state(TASK_INTERRUPTIBLE); \
- if (condition) \
- break; \
- if (!signal_pending(current)) { \
- spin_unlock_irqrestore(lock, flags); \
- schedule(); \
- spin_lock_irqsave(lock, flags); \
- continue; \
- } \
- ret = -ERESTARTSYS; \
- break; \
- } \
- current->state = TASK_RUNNING; \
- remove_wait_queue(&wq, &__wait); \
-} while (0)
-
-#define wait_cond_interruptible(wq, condition, lock, flags) \
-({ \
- int __ret = 0; \
- if (!(condition)) \
- __wait_cond_interruptible(wq, condition, lock, flags, \
- __ret); \
- __ret; \
-})
-
-#define __wait_cond_interruptible_timeout(wq, condition, lock, flags, \
- timeout, ret) \
-do { \
- signed long __timeout = timeout; \
- wait_queue_t __wait; \
- init_waitqueue_entry(&__wait, current); \
- \
- add_wait_queue(&wq, &__wait); \
- for (;;) { \
- set_current_state(TASK_INTERRUPTIBLE); \
- if (__timeout == 0) \
- break; \
- if (condition) \
- break; \
- if (!signal_pending(current)) { \
- spin_unlock_irqrestore(lock, flags); \
- __timeout = schedule_timeout(__timeout); \
- spin_lock_irqsave(lock, flags); \
- continue; \
- } \
- ret = -ERESTARTSYS; \
- break; \
- } \
- current->state = TASK_RUNNING; \
- remove_wait_queue(&wq, &__wait); \
-} while (0)
-
-#define wait_cond_interruptible_timeout(wq, condition, lock, flags, \
- timeout) \
-({ \
- int __ret = 0; \
- if (!(condition)) \
- __wait_cond_interruptible_timeout(wq, condition, lock, \
- flags, timeout, __ret); \
- __ret; \
-})
-
-
/* Defines */
-#define GS_VERSION_STR "v2.0"
-#define GS_VERSION_NUM 0x0200
+#define GS_VERSION_STR "v2.1"
+#define GS_VERSION_NUM 0x0201
#define GS_LONG_NAME "Gadget Serial"
#define GS_SHORT_NAME "g_serial"
@@ -843,6 +771,18 @@ exit_unlock_dev:
/*
* gs_close
*/
+
+#define GS_WRITE_FINISHED_EVENT_SAFELY(p) \
+({ \
+ unsigned long flags; \
+ int cond; \
+ \
+ spin_lock_irqsave(&(p)->port_lock, flags); \
+ cond = !(p)->port_dev || !gs_buf_data_avail((p)->port_write_buf); \
+ spin_unlock_irqrestore(&(p)->port_lock, flags); \
+ cond; \
+})
+
static void gs_close(struct tty_struct *tty, struct file *file)
{
unsigned long flags;
@@ -888,10 +828,9 @@ static void gs_close(struct tty_struct *tty, struct file *file)
/* at most GS_CLOSE_TIMEOUT seconds */
if (gs_buf_data_avail(port->port_write_buf) > 0) {
spin_unlock_irqrestore(&port->port_lock, flags);
- wait_cond_interruptible_timeout(port->port_write_wait,
- port->port_dev == NULL
- || gs_buf_data_avail(port->port_write_buf) == 0,
- &port->port_lock, flags, GS_CLOSE_TIMEOUT * HZ);
+ wait_event_interruptible_timeout(port->port_write_wait,
+ GS_WRITE_FINISHED_EVENT_SAFELY(port),
+ GS_CLOSE_TIMEOUT * HZ);
spin_lock_irqsave(&port->port_lock, flags);
}