From 44e4909e453eaa09c7de409fc9ee4ebefd986c1c Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Mon, 30 Nov 2009 13:16:41 +0000 Subject: [PATCH] tty: tty_port: Change the buffer allocator locking We want to be able to do this without regard for the activate/own open method being used which causes a problem using port->mutex. Add another mutex for now. Once everything uses port_open to do buffer allocs we can kill it back off Signed-off-by: Alan Cox Signed-off-by: Greg Kroah-Hartman --- drivers/char/tty_port.c | 9 +++++---- include/linux/tty.h | 1 + 2 files changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/char/tty_port.c b/drivers/char/tty_port.c index dd471d6..3ef644a 100644 --- a/drivers/char/tty_port.c +++ b/drivers/char/tty_port.c @@ -25,6 +25,7 @@ void tty_port_init(struct tty_port *port) init_waitqueue_head(&port->close_wait); init_waitqueue_head(&port->delta_msr_wait); mutex_init(&port->mutex); + mutex_init(&port->buf_mutex); spin_lock_init(&port->lock); port->close_delay = (50 * HZ) / 100; port->closing_wait = (3000 * HZ) / 100; @@ -34,10 +35,10 @@ EXPORT_SYMBOL(tty_port_init); int tty_port_alloc_xmit_buf(struct tty_port *port) { /* We may sleep in get_zeroed_page() */ - mutex_lock(&port->mutex); + mutex_lock(&port->buf_mutex); if (port->xmit_buf == NULL) port->xmit_buf = (unsigned char *)get_zeroed_page(GFP_KERNEL); - mutex_unlock(&port->mutex); + mutex_unlock(&port->buf_mutex); if (port->xmit_buf == NULL) return -ENOMEM; return 0; @@ -46,12 +47,12 @@ EXPORT_SYMBOL(tty_port_alloc_xmit_buf); void tty_port_free_xmit_buf(struct tty_port *port) { - mutex_lock(&port->mutex); + mutex_lock(&port->buf_mutex); if (port->xmit_buf != NULL) { free_page((unsigned long)port->xmit_buf); port->xmit_buf = NULL; } - mutex_unlock(&port->mutex); + mutex_unlock(&port->buf_mutex); } EXPORT_SYMBOL(tty_port_free_xmit_buf); diff --git a/include/linux/tty.h b/include/linux/tty.h index 6352ac2..e9269ca 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -212,6 +212,7 @@ struct tty_port { wait_queue_head_t delta_msr_wait; /* Modem status change */ unsigned long flags; /* TTY flags ASY_*/ struct mutex mutex; /* Locking */ + struct mutex buf_mutex; /* Buffer alloc lock */ unsigned char *xmit_buf; /* Optional buffer */ unsigned int close_delay; /* Close port delay */ unsigned int closing_wait; /* Delay for output */ -- 1.8.2.3