[PATCH v2] i2c-mpc: generate START condition after STOP caused by read i2c_msg

[Joakim Tjernlund]

>
> Ben Dooks said the following:
> > On Tue, May 26, 2009 at 01:30:21PM +0200, Esben Haabendal wrote:
> >> On Tue, May 19, 2009 at 7:22 AM, Esben Haabendal <eha at doredevelopment.dk> wrote:
> >> > This fixes MAL (arbitration lost) bug caused by illegal use of
> >> > RSTA (repeated START) after STOP condition generated after last byte
> >> > of reads. With this patch, it is possible to do an i2c_transfer() with
> >> > additional i2c_msg's following the I2C_M_RD messages.
> >> >
> >> > It still needs to be resolved if it is possible to fix this issue
> >> > by removing the STOP condition after reads in a robust way.
> >> >
> >> > Signed-off-by: Esben Haabendal <eha at doredevelopment.dk>
> >> > ---
> >> > ?drivers/i2c/busses/i2c-mpc.c | ? ?9 +++++++--
> >> > ?1 files changed, 7 insertions(+), 2 deletions(-)
> >>
> >> Any blockers to get this accepted?
> >
> > It would be nice to get an ack from someone who can actually test
> > the driver before getting this merged.
> >
> What is the state of this patch?
> Shouldn't we attack the problem on a more general way by inventing a
> Flag I2C_M_RESTART (or better I2C_M_NO_RESTART for backward compatibility)?
> This way the client driver is able to decide what it needs. If we do the
> choice within adapter, chance is about 50% to be wrong.

I have sent another patch (which I think is in Linus tree already) that
fixes the problem properly.

Can't remember if the driver handles M_RESTART or not. That is
a separate issue though.

      Jocke