On Thu, May 14, 2009 at 10:10:03AM +0200, Esben Haabendal wrote:
> This fixes MAL (arbitration lost) bug caused by illegal use of
> RSTA (repeated START) after STOP condition generated after last byte
> of reads.
>
Could you elaborate a bit, please? Like an example when the original bug
occured (so I could reproduce easily) and how this patch actually solves
the problem.
> Signed-off-by: Esben Haabendal <eha@xxxxxxxxxxxxxxxxxx>
> ---
> drivers/i2c/busses/i2c-mpc.c | 9 +++++++--
> 1 files changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c
> index 4af5c09..9fe05d9 100644
> --- a/drivers/i2c/busses/i2c-mpc.c
> +++ b/drivers/i2c/busses/i2c-mpc.c
> @@ -456,17 +456,22 @@ static int mpc_xfer(struct i2c_adapter *adap,
> struct i2c_msg *msgs, int num)
> }
>
> for (i = 0; ret >= 0 && i < num; i++) {
> + int restart = i;
> pmsg = &msgs[i];
> dev_dbg(i2c->dev,
> "Doing %s %d bytes to 0x%02x - %d of %d messages\n",
> pmsg->flags & I2C_M_RD ? "read" : "write",
> pmsg->len, pmsg->addr, i + 1, num);
> + if (i > 0 && ((pmsg-1)->flags & I2C_M_RD))
CodingStyle: Spaces around '-'
> + restart = 0;
> if (pmsg->flags & I2C_M_RD)
> ret =
> - mpc_read(i2c, pmsg->addr, pmsg->buf, pmsg->len, i);
> + mpc_read(i2c, pmsg->addr, pmsg->buf, pmsg->len,
> + restart);
> else
> ret =
> - mpc_write(i2c, pmsg->addr, pmsg->buf, pmsg->len, i);
> + mpc_write(i2c, pmsg->addr, pmsg->buf, pmsg->len,
> + restart);
> }
> mpc_i2c_stop(i2c);
> return (ret < 0) ? ret : num;
> --
> 1.6.0.4
>
> --
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--
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