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authorHaavard Skinnemoen <haavard.skinnemoen@atmel.com>2008-03-14 14:54:13 +0100
committerHaavard Skinnemoen <haavard.skinnemoen@atmel.com>2008-07-02 11:05:00 +0200
commite1c609efbc0333840f2af2d875ca52ed8ee18587 (patch)
tree29839e026441063433828813b6758a16aa88e9a6 /drivers/serial
parentf826caa44902ddbe93174f0b642d8abf9698c08e (diff)
atmel_serial: Drain console TX shifter before suspending
Funny things may happen if we stop the USART clock before the shifter is empty. Prevent this from happening by waiting until the shifter is completely drained before allowing suspend to continue. Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com> Cc: Andrew Victor <linux@maxim.org.za>
Diffstat (limited to 'drivers/serial')
-rw-r--r--drivers/serial/atmel_serial.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/serial/atmel_serial.c b/drivers/serial/atmel_serial.c
index 5f0414fc1b1..6aeef22bd20 100644
--- a/drivers/serial/atmel_serial.c
+++ b/drivers/serial/atmel_serial.c
@@ -1454,6 +1454,12 @@ static int atmel_serial_suspend(struct platform_device *pdev,
struct uart_port *port = platform_get_drvdata(pdev);
struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+ if (atmel_is_console_port(port) && console_suspend_enabled) {
+ /* Drain the TX shifter */
+ while (!(UART_GET_CSR(port) & ATMEL_US_TXEMPTY))
+ cpu_relax();
+ }
+
if (device_may_wakeup(&pdev->dev)
&& !atmel_serial_clk_will_stop())
enable_irq_wake(port->irq);