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SubjectRe: [5/7] i2c-designware: enable/disable the controller properly
On Tue, Apr 09, 2013 at 12:28:36PM +0300, Mika Westerberg wrote:
> On Tue, Apr 09, 2013 at 11:09:14AM +0200, Wolfram Sang wrote:
> >
> > > +static void __i2c_dw_enable(struct dw_i2c_dev *dev, bool enable)
> > > +{
> > > + int timeout = 100;
> > > +
> > > + do {
> > > + dw_writel(dev, enable, DW_IC_ENABLE);
> > > + if ((dw_readl(dev, DW_IC_ENABLE_STATUS) & 1) == enable)
> > > + return;
> > > +
> > > + usleep_range(25, 250);
> >
> > This would wait 25ms max. Is there a timeout value specified in the docs?
>
> The datasheet says something like:
>
> 1. Define a timer interval (t_i2c_poll) equal 10 times the highest
> signaling period. For 400kHz this is 25us.
>
> 2. Define max timeout parameter, MAX_T_POLL_COUNT, such that if any
> repeated operation exeeds this maximum, an error is reported.
>
> In this case I have:
>
> t_i2c_poll = 25 (to 250 us)
> MAX_T_POLL_COUNT = 100

Maybe worth a comment?

Other than that, the series looks fine to me.


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