[patch 2.6.28-rc2] atmel_serial: keep clock off when it's not needed

[David Brownell]

From: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx>

The atmel_serial driver is mismanaging its clock by leaving it on
at all times ... the whole point of clock management is to leave
it off unless it's actively needed, which conserves power!!

Signed-off-by: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx>
---
 drivers/serial/atmel_serial.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/serial/atmel_serial.c
+++ b/drivers/serial/atmel_serial.c
@@ -1258,6 +1258,8 @@ static void __devinit atmel_init_port(st
 		atmel_port->clk = clk_get(&pdev->dev, "usart");
 		clk_enable(atmel_port->clk);
 		port->uartclk = clk_get_rate(atmel_port->clk);
+		clk_disable(atmel_port->clk);
+		/* only enable clock when USART is in use */
 	}
 
 	atmel_port->use_dma_rx = data->use_dma_rx;
@@ -1544,7 +1546,6 @@ err_add_port:
 	port->rx_ring.buf = NULL;
 err_alloc_ring:
 	if (!atmel_is_console_port(&port->uart)) {
-		clk_disable(port->clk);
 		clk_put(port->clk);
 		port->clk = NULL;
 	}
@@ -1568,7 +1569,6 @@ static int __devexit atmel_serial_remove
 
 	/* "port" is allocated statically, so we shouldn't free it */
 
-	clk_disable(atmel_port->clk);
 	clk_put(atmel_port->clk);
 
 	return ret;
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/