From: Robert Baldyga Date: Mon, 24 Nov 2014 06:56:21 +0000 (+0100) Subject: serial: samsung: wait for transfer completion before clock disable X-Git-Tag: v3.16.35~3311 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=3fc6bca58b6c568a599264e920dd6e197600a1b0;p=thirdparty%2Fkernel%2Fstable.git serial: samsung: wait for transfer completion before clock disable commit 1ff383a4c3eda8893ec61b02831826e1b1f46b41 upstream. This patch adds waiting until transmit buffer and shifter will be empty before clock disabling. Without this fix it's possible to have clock disabled while data was not transmited yet, which causes unproper state of TX line and problems in following data transfers. Signed-off-by: Robert Baldyga Signed-off-by: Greg Kroah-Hartman Signed-off-by: Luis Henriques --- diff --git a/drivers/tty/serial/samsung.c b/drivers/tty/serial/samsung.c index c1d3ebdf3b97c..7268409dfc687 100644 --- a/drivers/tty/serial/samsung.c +++ b/drivers/tty/serial/samsung.c @@ -567,11 +567,15 @@ static void s3c24xx_serial_pm(struct uart_port *port, unsigned int level, unsigned int old) { struct s3c24xx_uart_port *ourport = to_ourport(port); + int timeout = 10000; ourport->pm_level = level; switch (level) { case 3: + while (--timeout && !s3c24xx_serial_txempty_nofifo(port)) + udelay(100); + if (!IS_ERR(ourport->baudclk)) clk_disable_unprepare(ourport->baudclk);