From mboxrd@z Thu Jan 1 00:00:00 1970 From: Felipe Balbi Subject: [PATCH v4 17/21] serial: omap: make sure to put() on poll_get_char Date: Thu, 6 Sep 2012 15:45:36 +0300 Message-ID: <1346935540-1792-18-git-send-email-balbi@ti.com> References: <20120906122948.GC29202@arwen.pp.htv.fi> <1346935540-1792-1-git-send-email-balbi@ti.com> Return-path: In-Reply-To: <1346935540-1792-1-git-send-email-balbi@ti.com> Sender: linux-kernel-owner@vger.kernel.org To: Greg KH Cc: alan@linux.intel.com, Tony Lindgren , Kevin Hilman , Linux OMAP Mailing List , Linux ARM Kernel Mailing List , linux-serial@vger.kernel.org, Linux Kernel Mailing List , Santosh Shilimkar , Shubhrajyoti Datta , Sourav Poddar , Felipe Balbi List-Id: linux-serial@vger.kernel.org if we would reach serial_omap_get_char() while Data Ready bit isn't set, we would return from it without kicking our pm timer. This would mean we would, eventually, have an unbalanced pm_runtime_get on our device which would prevent it from ever sleeping again. Tested-by: Shubhrajyoti D Signed-off-by: Felipe Balbi --- drivers/tty/serial/omap-serial.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c index 7531147..6a58f4f 100644 --- a/drivers/tty/serial/omap-serial.c +++ b/drivers/tty/serial/omap-serial.c @@ -1005,12 +1005,17 @@ static int serial_omap_poll_get_char(struct uart_port *port) pm_runtime_get_sync(up->dev); status = serial_in(up, UART_LSR); - if (!(status & UART_LSR_DR)) - return NO_POLL_CHAR; + if (!(status & UART_LSR_DR)) { + status = NO_POLL_CHAR; + goto out; + } status = serial_in(up, UART_RX); + +out: pm_runtime_mark_last_busy(up->dev); pm_runtime_put_autosuspend(up->dev); + return status; } -- 1.7.12.rc3