On Wed, May 16, 2012 at 03:20:19PM +0800, [email protected] wrote: > From: Michael Hennerich <[email protected]> > > For transfer counts > 255 bytes i2c-bfin-twi sets the data > transfer counter DCNT to 0xFF indicating unlimited transfers. > It then uses a flag iface->manual_stop to manually issue the STOP > condition, once the required amount of bytes are received. > > We found that on I2C receive operation issuing the STOP condition > together with a FULL RCV FIFO (2bytes) will cause SDA and SCL be > constantly driven low. > > Temporary workaround until further investigation: > Discard the RCV FIFO before issuing the STOP condition. > > Signed-off-by: Michael Hennerich <[email protected]> > Signed-off-by: Sonic Zhang <[email protected]> > > git-svn-id: svn://localhost/svn/linux-kernel/trunk@9011 > 526b6c2d-f592-4532-a319-5dd88ccb003d
Please remove this line.
> ---
> drivers/i2c/busses/i2c-bfin-twi.c | 4 ++++
> 1 files changed, 4 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-bfin-twi.c
> b/drivers/i2c/busses/i2c-bfin-twi.c
> index cdb59e5..e6dd3c9 100644
> --- a/drivers/i2c/busses/i2c-bfin-twi.c
> +++ b/drivers/i2c/busses/i2c-bfin-twi.c
> @@ -131,6 +131,10 @@ static void bfin_twi_handle_interrupt(struct
> bfin_twi_iface *iface,
> iface->transPtr++;
> iface->readNum--;
> } else if (iface->manual_stop) {
> + /* Avoid possible bus stall -
> + * Flush FIFO before issuing the STOP condition
> + */
> + read_RCV_DATA16(iface);
Please mention that this is currently only a workaround, so people know
there could be still a proper solution.
> write_MASTER_CTL(iface,
> read_MASTER_CTL(iface) | STOP);
> } else if (iface->cur_mode == TWI_I2C_MODE_REPEAT &&
> --
> 1.7.0.4
>
>
--
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