Hi Wolfram,
On Wed, Nov 19, 2014 at 10:21:22AM +0100, Wolfram Sang wrote:
> On Fri, Nov 07, 2014 at 12:10:44PM +0000, Andrew Jackson wrote:
> > If the Designware core is configured with IC_EMPTYFIFO_HOLD_MASTER_EN
> > set to zero, allowing the TX FIFO to become empty causes a STOP
> > condition to be generated on the I2C bus. If the transmit FIFO
> > threshold is set too high, an erroneous STOP condition can be
> > generated on long transfers - particularly where the interrupt
> > latency is extended.
> >
> > Signed-off-by: Andrew Jackson <andrew.jack...@arm.com>
> > Signed-off-by: Liviu Dudau <liviu.du...@arm.com>
>
> So, what do other designware users think of this change (nice CC list
> BTW, Andrew). Adding Mika, too.
I don't have access to this hardware anymore so I can't test. As far as I
remember the spec this change should be OK.
baruch
> > drivers/i2c/busses/i2c-designware-core.c | 2 +-
> > 1 files changed, 1 insertions(+), 1 deletions(-)
> >
> > diff --git a/drivers/i2c/busses/i2c-designware-core.c
> > b/drivers/i2c/busses/i2c-designware-core.c
> > index 3c20e4b..e070edd 100644
> > --- a/drivers/i2c/busses/i2c-designware-core.c
> > +++ b/drivers/i2c/busses/i2c-designware-core.c
> > @@ -363,7 +363,7 @@ int i2c_dw_init(struct dw_i2c_dev *dev)
> > }
> >
> > /* Configure Tx/Rx FIFO threshold levels */
> > - dw_writel(dev, dev->tx_fifo_depth - 1, DW_IC_TX_TL);
> > + dw_writel(dev, dev->tx_fifo_depth / 2, DW_IC_TX_TL);
> > dw_writel(dev, 0, DW_IC_RX_TL);
> >
> > /* configure the i2c master */
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