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authorPeter Hurley <peter@hurleysoftware.com>2015-10-10 23:00:55 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-10-18 07:11:29 +0300
commit9b9ab1b3f0860138681862cf6e4c48be59377ef1 (patch)
tree5dcd70bcb2ab9a42db39a5c7d5311f08795d4a89
parentcc2aaabfd6d6335e2156781ca67715b4de17f993 (diff)
downloadlinux-9b9ab1b3f0860138681862cf6e4c48be59377ef1.tar.xz
tty: r3964: Use tty->read_wait waitqueue
The tty core provides read_wait waitqueue specifically for line disciplines to wait readers; otherwise, the line discipline may miss wakeups generated by the tty core. NB: The tty core already provides serialization for the line discipline's close() method, and guarantees no readers or writers will be using the closing instance of the line discipline. Completely remove that wakeup. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/tty/n_r3964.c10
-rw-r--r--include/linux/n_r3964.h3
2 files changed, 4 insertions, 9 deletions
diff --git a/drivers/tty/n_r3964.c b/drivers/tty/n_r3964.c
index 8b157d68a03e..6fdef921cdb7 100644
--- a/drivers/tty/n_r3964.c
+++ b/drivers/tty/n_r3964.c
@@ -276,7 +276,7 @@ static void remove_from_tx_queue(struct r3964_info *pInfo, int error_code)
add_msg(pHeader->owner, R3964_MSG_ACK, pHeader->length,
error_code, NULL);
}
- wake_up_interruptible(&pInfo->read_wait);
+ wake_up_interruptible(&pInfo->tty->read_wait);
}
spin_lock_irqsave(&pInfo->lock, flags);
@@ -542,7 +542,7 @@ static void on_receive_block(struct r3964_info *pInfo)
pBlock);
}
}
- wake_up_interruptible(&pInfo->read_wait);
+ wake_up_interruptible(&pInfo->tty->read_wait);
pInfo->state = R3964_IDLE;
@@ -979,7 +979,6 @@ static int r3964_open(struct tty_struct *tty)
spin_lock_init(&pInfo->lock);
pInfo->tty = tty;
- init_waitqueue_head(&pInfo->read_wait);
pInfo->priority = R3964_MASTER;
pInfo->rx_first = pInfo->rx_last = NULL;
pInfo->tx_first = pInfo->tx_last = NULL;
@@ -1045,7 +1044,6 @@ static void r3964_close(struct tty_struct *tty)
}
/* Free buffers: */
- wake_up_interruptible(&pInfo->read_wait);
kfree(pInfo->rx_buf);
TRACE_M("r3964_close - rx_buf kfree %p", pInfo->rx_buf);
kfree(pInfo->tx_buf);
@@ -1077,7 +1075,7 @@ static ssize_t r3964_read(struct tty_struct *tty, struct file *file,
goto unlock;
}
/* block until there is a message: */
- wait_event_interruptible_tty(tty, pInfo->read_wait,
+ wait_event_interruptible_tty(tty, tty->read_wait,
(pMsg = remove_msg(pInfo, pClient)));
}
@@ -1227,7 +1225,7 @@ static unsigned int r3964_poll(struct tty_struct *tty, struct file *file,
pClient = findClient(pInfo, task_pid(current));
if (pClient) {
- poll_wait(file, &pInfo->read_wait, wait);
+ poll_wait(file, &tty->read_wait, wait);
spin_lock_irqsave(&pInfo->lock, flags);
pMsg = pClient->first_msg;
spin_unlock_irqrestore(&pInfo->lock, flags);
diff --git a/include/linux/n_r3964.h b/include/linux/n_r3964.h
index 5d0b2a1dee69..e9adb4226224 100644
--- a/include/linux/n_r3964.h
+++ b/include/linux/n_r3964.h
@@ -152,9 +152,6 @@ struct r3964_info {
unsigned char *rx_buf; /* ring buffer */
unsigned char *tx_buf;
- wait_queue_head_t read_wait;
- //struct wait_queue *read_wait;
-
struct r3964_block_header *rx_first;
struct r3964_block_header *rx_last;
struct r3964_block_header *tx_first;