From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Hurley Subject: [PATCH 14/26] serial: core: Document and assert lock requirements for irq helpers Date: Tue, 2 Sep 2014 17:39:23 -0400 Message-ID: <1409693975-1028-15-git-send-email-peter@hurleysoftware.com> References: <1409693975-1028-1-git-send-email-peter@hurleysoftware.com> Return-path: In-Reply-To: <1409693975-1028-1-git-send-email-peter@hurleysoftware.com> Sender: linux-kernel-owner@vger.kernel.org To: Greg Kroah-Hartman Cc: Jiri Slaby , One Thousand Gnomes , linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, Peter Hurley List-Id: linux-serial@vger.kernel.org The serial core provides two helper functions, uart_handle_dcd_change() and uart_handle_cts_change(), for UART drivers to use at interrupt time. The serial core expects the UART driver to hold the uart port lock when calling these helpers to prevent state corruption. Signed-off-by: Peter Hurley --- drivers/tty/serial/serial_core.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index 732d386..b50050d 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -2731,6 +2731,8 @@ EXPORT_SYMBOL(uart_match_port); * uart_handle_dcd_change - handle a change of carrier detect state * @uport: uart_port structure for the open port * @status: new carrier detect status, nonzero if active + * + * Caller must hold uport->lock */ void uart_handle_dcd_change(struct uart_port *uport, unsigned int status) { @@ -2738,6 +2740,8 @@ void uart_handle_dcd_change(struct uart_port *uport, unsigned int status) struct tty_struct *tty = port->tty; struct tty_ldisc *ld; + warn_not_spin_locked(&uport->lock); + if (tty) { ld = tty_ldisc_ref(tty); if (ld) { @@ -2762,12 +2766,16 @@ EXPORT_SYMBOL_GPL(uart_handle_dcd_change); * uart_handle_cts_change - handle a change of clear-to-send state * @uport: uart_port structure for the open port * @status: new clear to send status, nonzero if active + * + * Caller must hold uport->lock */ void uart_handle_cts_change(struct uart_port *uport, unsigned int status) { struct tty_port *port = &uport->state->port; struct tty_struct *tty = port->tty; + warn_not_spin_locked(&uport->lock); + uport->icount.cts++; if (tty_port_cts_enabled(port)) { -- 2.1.0