[PATCH 1/4] i2c: designware: No need to disable already disabled controller

[Mika Westerberg]

If the controller is already in desired state (enabled/disabled) there is
no point in setting its state again.

Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
---
 drivers/i2c/busses/i2c-designware-core.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c
index b58ecf19e767..b0792675b970 100644
--- a/drivers/i2c/busses/i2c-designware-core.c
+++ b/drivers/i2c/busses/i2c-designware-core.c
@@ -258,6 +258,10 @@ static void __i2c_dw_enable(struct dw_i2c_dev *dev, bool enable)
 {
 	int timeout = 100;
 
+	/* In case the controller is already in desired state */
+	if ((dw_readl(dev, DW_IC_ENABLE_STATUS) & 1) == enable)
+		return;
+
 	do {
 		dw_writel(dev, enable, DW_IC_ENABLE);
 		if ((dw_readl(dev, DW_IC_ENABLE_STATUS) & 1) == enable)
-- 
2.0.0.rc2

--
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/