Re: [PATCH v2 2/7] i2c: npcm: correct the read/write operation procedure

[Tyrone Ting]

Hi Andi:

Thank you for your review.

Andi Shyti <andi.shyti@xxxxxxxxxx> 於 2024年9月6日 週五 上午5:29寫道：
>
> Hi Tyronne,
>
> On Fri, Aug 30, 2024 at 11:46:35AM GMT, Tyrone Ting wrote:
> > Originally the driver uses the XMIT bit in SMBnST register to decide
> > the upcoming i2c transaction. If XMIT bit is 1, then it will be an i2c
> > write operation. If it's 0, then a read operation will be executed.
> >
> > After checking the datasheet, the XMIT bit is valid when the i2c module
> > is acting in a slave role. Use the software status to control the i2c
> > transaction flow instead when the i2c module is acting in a master role.
> >
> > Fixes: 48acf8292280 ("i2c: Remove redundant comparison in npcm_i2c_reg_slave")
>
> Fixes needs to be used if you are fixing a bug (crash,
> device malfunction, etc.). If you want to use it, please describe
> the bug you are fixing. Otherwise, please, remove it.
>
Understood. I'll remove the Fixes tag in the next patch set.

> > Signed-off-by: Tyrone Ting <kfting@xxxxxxxxxxx>
> > ---
> >  drivers/i2c/busses/i2c-npcm7xx.c | 7 ++-----
> >  1 file changed, 2 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/i2c/busses/i2c-npcm7xx.c b/drivers/i2c/busses/i2c-npcm7xx.c
> > index bbcb4d6668ce..2b76dbfba438 100644
> > --- a/drivers/i2c/busses/i2c-npcm7xx.c
> > +++ b/drivers/i2c/busses/i2c-npcm7xx.c
> > @@ -1628,13 +1628,10 @@ static void npcm_i2c_irq_handle_sda(struct npcm_i2c *bus, u8 i2cst)
> >                       npcm_i2c_wr_byte(bus, bus->dest_addr | BIT(0));
> >       /* SDA interrupt, after start\restart */
> >       } else {
> > -             if (NPCM_I2CST_XMIT & i2cst) {
> > -                     bus->operation = I2C_WRITE_OPER;
> > +             if (bus->operation == I2C_WRITE_OPER)
> >                       npcm_i2c_irq_master_handler_write(bus);
> > -             } else {
> > -                     bus->operation = I2C_READ_OPER;
> > +             else if (bus->operation == I2C_READ_OPER)
> >                       npcm_i2c_irq_master_handler_read(bus);
>
> mmmhhh... you are changing the logic here and you are not
> describing the logic change in the commit log.
>
> Without looking at the details, if this is a state machine you
> are breaking it.
>
> Can anyone from the ARM/NUVOTON NPCM supporters and reviewers
> take a look at this patch?
>
> Thanks,
> Andi
>
> > -             }
> >       }
> >  }
> >
> > --
> > 2.34.1
> >

Thank you.

Regards,
Tyrone