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authorRobert Baldyga <r.baldyga@samsung.com>2014-11-24 07:56:21 +0100
committerBen Hutchings <ben@decadent.org.uk>2015-02-20 00:49:25 +0000
commit375c2b688c392e597d0a065451adeee9ba1bf7e4 (patch)
treeb9d1c6e5d18904f6f4ca24ac7bba353b91cd3961 /drivers/tty
parent7010f0f36b3b2e6ae6a584060449a3100feee71e (diff)
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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 <r.baldyga@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'drivers/tty')
-rw-r--r--drivers/tty/serial/samsung.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/tty/serial/samsung.c b/drivers/tty/serial/samsung.c
index b31f1c3..626e75b 100644
--- a/drivers/tty/serial/samsung.c
+++ b/drivers/tty/serial/samsung.c
@@ -519,11 +519,15 @@ 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) && ourport->baudclk != NULL)
clk_disable(ourport->baudclk);