[PATCH 44/68] tty: release BTM while sleeping in block_til_ready

From: Greg Kroah-Hartman
Date: Tue Aug 10 2010 - 18:03:48 EST


From: Arnd Bergmann <arnd@xxxxxxxx>

Most tty drivers may block while opening a device.
Since this possibly depends on another thread
closing it first and both threads may need the BTM,
we need to release it here.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Alan Cox <alan@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
---
drivers/char/amiserial.c | 2 ++
drivers/char/ip2/ip2main.c | 4 ++++
drivers/char/serial167.c | 4 +++-
drivers/char/specialix.c | 2 ++
drivers/char/synclink.c | 2 ++
drivers/char/synclink_gt.c | 2 ++
drivers/char/synclinkmp.c | 2 ++
drivers/char/tty_port.c | 2 ++
drivers/serial/68328serial.c | 2 ++
drivers/serial/68360serial.c | 2 ++
drivers/serial/crisv10.c | 2 ++
11 files changed, 25 insertions(+), 1 deletions(-)

diff --git a/drivers/char/amiserial.c b/drivers/char/amiserial.c
index 8228e61..a11c8c9 100644
--- a/drivers/char/amiserial.c
+++ b/drivers/char/amiserial.c
@@ -1710,7 +1710,9 @@ static int block_til_ready(struct tty_struct *tty, struct file * filp,
printk("block_til_ready blocking: ttys%d, count = %d\n",
info->line, state->count);
#endif
+ tty_unlock();
schedule();
+ tty_lock();
}
__set_current_state(TASK_RUNNING);
remove_wait_queue(&info->open_wait, &wait);
diff --git a/drivers/char/ip2/ip2main.c b/drivers/char/ip2/ip2main.c
index 911e1da..07f3ea3 100644
--- a/drivers/char/ip2/ip2main.c
+++ b/drivers/char/ip2/ip2main.c
@@ -1486,7 +1486,9 @@ ip2_open( PTTY tty, struct file *pFile )

if ( tty_hung_up_p(pFile) || ( pCh->flags & ASYNC_CLOSING )) {
if ( pCh->flags & ASYNC_CLOSING ) {
+ tty_unlock();
schedule();
+ tty_lock();
}
if ( tty_hung_up_p(pFile) ) {
set_current_state( TASK_RUNNING );
@@ -1548,7 +1550,9 @@ ip2_open( PTTY tty, struct file *pFile )
rc = (( pCh->flags & ASYNC_HUP_NOTIFY ) ? -EAGAIN : -ERESTARTSYS);
break;
}
+ tty_unlock();
schedule();
+ tty_lock();
}
set_current_state( TASK_RUNNING );
remove_wait_queue(&pCh->open_wait, &wait);
diff --git a/drivers/char/serial167.c b/drivers/char/serial167.c
index 90b3ec0..f646725 100644
--- a/drivers/char/serial167.c
+++ b/drivers/char/serial167.c
@@ -1786,7 +1786,9 @@ block_til_ready(struct tty_struct *tty, struct file *filp,
tty->name, info->count);
/**/
#endif
- schedule();
+ tty_unlock();
+ schedule();
+ tty_lock();
}
__set_current_state(TASK_RUNNING);
remove_wait_queue(&info->open_wait, &wait);
diff --git a/drivers/char/specialix.c b/drivers/char/specialix.c
index 7be456f..9f8495b 100644
--- a/drivers/char/specialix.c
+++ b/drivers/char/specialix.c
@@ -1365,7 +1365,9 @@ static int block_til_ready(struct tty_struct *tty, struct file *filp,
retval = -ERESTARTSYS;
break;
}
+ tty_unlock();
schedule();
+ tty_lock();
}

set_current_state(TASK_RUNNING);
diff --git a/drivers/char/synclink.c b/drivers/char/synclink.c
index 2b03d4d..a2a5800 100644
--- a/drivers/char/synclink.c
+++ b/drivers/char/synclink.c
@@ -3349,7 +3349,9 @@ static int block_til_ready(struct tty_struct *tty, struct file * filp,
printk("%s(%d):block_til_ready blocking on %s count=%d\n",
__FILE__,__LINE__, tty->driver->name, port->count );

+ tty_unlock();
schedule();
+ tty_lock();
}

set_current_state(TASK_RUNNING);
diff --git a/drivers/char/synclink_gt.c b/drivers/char/synclink_gt.c
index 5a602eb..fef80cf 100644
--- a/drivers/char/synclink_gt.c
+++ b/drivers/char/synclink_gt.c
@@ -3244,7 +3244,9 @@ static int block_til_ready(struct tty_struct *tty, struct file *filp,
}

DBGINFO(("%s block_til_ready wait\n", tty->driver->name));
+ tty_unlock();
schedule();
+ tty_lock();
}

set_current_state(TASK_RUNNING);
diff --git a/drivers/char/synclinkmp.c b/drivers/char/synclinkmp.c
index ac447c7..e56caf7 100644
--- a/drivers/char/synclinkmp.c
+++ b/drivers/char/synclinkmp.c
@@ -3365,7 +3365,9 @@ static int block_til_ready(struct tty_struct *tty, struct file *filp,
printk("%s(%d):%s block_til_ready() count=%d\n",
__FILE__,__LINE__, tty->driver->name, port->count );

+ tty_unlock();
schedule();
+ tty_lock();
}

set_current_state(TASK_RUNNING);
diff --git a/drivers/char/tty_port.c b/drivers/char/tty_port.c
index 35eb304..33d37d2 100644
--- a/drivers/char/tty_port.c
+++ b/drivers/char/tty_port.c
@@ -294,7 +294,9 @@ int tty_port_block_til_ready(struct tty_port *port,
retval = -ERESTARTSYS;
break;
}
+ tty_unlock();
schedule();
+ tty_lock();
}
finish_wait(&port->open_wait, &wait);

diff --git a/drivers/serial/68328serial.c b/drivers/serial/68328serial.c
index 9330edb..d8204f4 100644
--- a/drivers/serial/68328serial.c
+++ b/drivers/serial/68328serial.c
@@ -1235,7 +1235,9 @@ static int block_til_ready(struct tty_struct *tty, struct file * filp,
retval = -ERESTARTSYS;
break;
}
+ tty_unlock();
schedule();
+ tty_lock();
}
current->state = TASK_RUNNING;
remove_wait_queue(&info->open_wait, &wait);
diff --git a/drivers/serial/68360serial.c b/drivers/serial/68360serial.c
index edcf1cc..0dff3bb 100644
--- a/drivers/serial/68360serial.c
+++ b/drivers/serial/68360serial.c
@@ -1860,7 +1860,9 @@ static int block_til_ready(struct tty_struct *tty, struct file * filp,
printk("block_til_ready blocking: ttys%d, count = %d\n",
info->line, state->count);
#endif
+ tty_unlock();
schedule();
+ tty_lock();
}
current->state = TASK_RUNNING;
remove_wait_queue(&info->open_wait, &wait);
diff --git a/drivers/serial/crisv10.c b/drivers/serial/crisv10.c
index 8e356c5..5696710 100644
--- a/drivers/serial/crisv10.c
+++ b/drivers/serial/crisv10.c
@@ -4066,7 +4066,9 @@ block_til_ready(struct tty_struct *tty, struct file * filp,
printk("block_til_ready blocking: ttyS%d, count = %d\n",
info->line, info->count);
#endif
+ tty_unlock();
schedule();
+ tty_lock();
}
set_current_state(TASK_RUNNING);
remove_wait_queue(&info->open_wait, &wait);
--
1.7.2

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