Re: [PATCH V4] i2c: designware: fix wrong Tx/Rx FIFO for ACPI

[Jarkko Nikula]

On 12/14/2016 05:20 AM, Tin Huynh wrote:
> On Tue, Dec 13, 2016 at 6:25 PM, Andy Shevchenko
> > > +     param = i2c_dw_read_comp_param(dev);
> > > +     tx_fifo_depth = ((param >> 16) & 0xff) + 1;
> > > +     rx_fifo_depth = ((param >> 8)  & 0xff) + 1;
> > > +     if (!dev->tx_fifo_depth) {
> > > +             dev->tx_fifo_depth = tx_fifo_depth;
> > > +             dev->rx_fifo_depth = rx_fifo_depth;
> > > +             dev->adapter.nr = id;
> > > +     } else if (tx_fifo_depth > 1) {
> >
> > This makes sense now, though I would add a comment here and use >= 2 to
> > reflect datasheet.
> >
> >                 /*
> >                  * Choose minimum values between HW and interface
> >                  * driver provided.
> >                  */
> I will implement as your comment. However , because adding 1 to the
> value , can i use > 2  or >=3 ?

either > 1 or >= 2 since register value 0x01 from HW means FIFO depth 2 
and register value 0x00 is reserved.

--
Jarkko