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

Michael Lawnick ml.lawnick at gmx.de
Fri Dec 4 02:09:57 EST 2009

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.

Just my 2 Cents.


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