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

Mika Westerberg
2014-05-15T14:37:30Z

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@linux.intel.com>
---
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