Messages in this thread | | | Date | Mon, 2 Jun 2014 18:12:34 +0200 | From | Wolfram Sang <> | Subject | Re: [PATCH 1/4] i2c: designware: No need to disable already disabled controller |
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On Thu, May 15, 2014 at 05:37:21PM +0300, Mika Westerberg wrote: > 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> > ---
Does it have a side-effect when setting then enable bit again? Otherwise it will exit the loop immediately on the first try. Not too bad IMO given the additional code saved.
> 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 > [unhandled content-type:application/pgp-signature] | |