Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757208AbZKRO0f (ORCPT ); Wed, 18 Nov 2009 09:26:35 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757198AbZKRO0f (ORCPT ); Wed, 18 Nov 2009 09:26:35 -0500 Received: from earthlight.etchedpixels.co.uk ([81.2.110.250]:46395 "EHLO bob.linux.org.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1757197AbZKRO0d (ORCPT ); Wed, 18 Nov 2009 09:26:33 -0500 From: Alan Cox Subject: [PATCH 1/7] tty_port: Change the buffer allocator locking To: greg@kroah.com, linux-kernel@vger.kernel.org Date: Wed, 18 Nov 2009 14:10:09 +0000 Message-ID: <20091118141005.2798.43363.stgit@localhost.localdomain> In-Reply-To: <20091118140935.2798.32517.stgit@localhost.localdomain> References: <20091118140935.2798.32517.stgit@localhost.localdomain> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2480 Lines: 71 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 --- 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 5c2deef..8825255 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 */ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/