2022-02-08 13:20:46

by J. Neuschäfer

[permalink] [raw]
Subject: Re: [PATCH v1 4/6] i2c: npcm: Handle spurious interrupts

Hello,
some comments below.

On Mon, Feb 07, 2022 at 02:33:36PM +0800, Tyrone Ting wrote:
> From: Tali Perry <[email protected]>
>
> In order to better handle spurious interrupts:
> 1. Disable incoming interrupts in master only mode.
> 2. Clear EOB after every interrupt.

For those who rarely deal with this particular I2C controller, please
add the meaning of EOB, e.g.: "2. Clear end of busy (EOB) after every interrupt"

> 3. Return correct status during interrupt.
>
> Fixes: 56a1485b102e ("i2c: npcm7xx: Add Nuvoton NPCM I2C controller driver")
> Signed-off-by: Tali Perry <[email protected]>
> Signed-off-by: Tyrone Ting <[email protected]>
> ---
> drivers/i2c/busses/i2c-npcm7xx.c | 96 +++++++++++++++++++++-----------
> 1 file changed, 65 insertions(+), 31 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-npcm7xx.c b/drivers/i2c/busses/i2c-npcm7xx.c
> index 5c22e69afe34..1ddf309b91a3 100644
> --- a/drivers/i2c/busses/i2c-npcm7xx.c
> +++ b/drivers/i2c/busses/i2c-npcm7xx.c
> @@ -360,14 +360,14 @@ static int npcm_i2c_get_SCL(struct i2c_adapter *_adap)
> {
> struct npcm_i2c *bus = container_of(_adap, struct npcm_i2c, adap);
>
> - return !!(I2CCTL3_SCL_LVL & ioread32(bus->reg + NPCM_I2CCTL3));
> + return !!(I2CCTL3_SCL_LVL & ioread8(bus->reg + NPCM_I2CCTL3));
> }
>
> static int npcm_i2c_get_SDA(struct i2c_adapter *_adap)
> {
> struct npcm_i2c *bus = container_of(_adap, struct npcm_i2c, adap);
>
> - return !!(I2CCTL3_SDA_LVL & ioread32(bus->reg + NPCM_I2CCTL3));
> + return !!(I2CCTL3_SDA_LVL & ioread8(bus->reg + NPCM_I2CCTL3));
> }

This change seems unrelated and isn't mentioned in the commit message.
Please remove it or put it into a separate commit, or document the
motivation in the commit message.


>
> static inline u16 npcm_i2c_get_index(struct npcm_i2c *bus)
> @@ -564,6 +564,15 @@ static inline void npcm_i2c_nack(struct npcm_i2c *bus)
> iowrite8(val, bus->reg + NPCM_I2CCTL1);
> }
>
> +static inline void npcm_i2c_clear_master_status(struct npcm_i2c *bus)
> +{
> + u8 val;
> +
> + /* Clear NEGACK, STASTR and BER bits */
> + val = NPCM_I2CST_BER | NPCM_I2CST_NEGACK | NPCM_I2CST_STASTR;
> + iowrite8(val, bus->reg + NPCM_I2CST);

Small nitpick: Please keep the order the same between comment and code,
e.g.:

/* Clear BER, NEGACK and STASTR bits */
val = NPCM_I2CST_BER | NPCM_I2CST_NEGACK | NPCM_I2CST_STASTR;



Best regards,
Jonathan


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2022-02-09 11:09:54

by Tyrone Ting

[permalink] [raw]
Subject: Re: [PATCH v1 4/6] i2c: npcm: Handle spurious interrupts

Hi Jonathan:

Thank you for your comments.

Regards,
Tyrone

Jonathan Neuschäfer <[email protected]> 於 2022年2月7日 週一 下午7:40寫道:
>
> Hello,
> some comments below.
>
> On Mon, Feb 07, 2022 at 02:33:36PM +0800, Tyrone Ting wrote:
> > From: Tali Perry <[email protected]>
> >
> > In order to better handle spurious interrupts:
> > 1. Disable incoming interrupts in master only mode.
> > 2. Clear EOB after every interrupt.
>
> For those who rarely deal with this particular I2C controller, please
> add the meaning of EOB, e.g.: "2. Clear end of busy (EOB) after every interrupt"
>

Okay, it will be addressed.

> > 3. Return correct status during interrupt.
> >
> > Fixes: 56a1485b102e ("i2c: npcm7xx: Add Nuvoton NPCM I2C controller driver")
> > Signed-off-by: Tali Perry <[email protected]>
> > Signed-off-by: Tyrone Ting <[email protected]>
> > ---
> > drivers/i2c/busses/i2c-npcm7xx.c | 96 +++++++++++++++++++++-----------
> > 1 file changed, 65 insertions(+), 31 deletions(-)
> >
> > diff --git a/drivers/i2c/busses/i2c-npcm7xx.c b/drivers/i2c/busses/i2c-npcm7xx.c
> > index 5c22e69afe34..1ddf309b91a3 100644
> > --- a/drivers/i2c/busses/i2c-npcm7xx.c
> > +++ b/drivers/i2c/busses/i2c-npcm7xx.c
> > @@ -360,14 +360,14 @@ static int npcm_i2c_get_SCL(struct i2c_adapter *_adap)
> > {
> > struct npcm_i2c *bus = container_of(_adap, struct npcm_i2c, adap);
> >
> > - return !!(I2CCTL3_SCL_LVL & ioread32(bus->reg + NPCM_I2CCTL3));
> > + return !!(I2CCTL3_SCL_LVL & ioread8(bus->reg + NPCM_I2CCTL3));
> > }
> >
> > static int npcm_i2c_get_SDA(struct i2c_adapter *_adap)
> > {
> > struct npcm_i2c *bus = container_of(_adap, struct npcm_i2c, adap);
> >
> > - return !!(I2CCTL3_SDA_LVL & ioread32(bus->reg + NPCM_I2CCTL3));
> > + return !!(I2CCTL3_SDA_LVL & ioread8(bus->reg + NPCM_I2CCTL3));
> > }
>
> This change seems unrelated and isn't mentioned in the commit message.
> Please remove it or put it into a separate commit, or document the
> motivation in the commit message.
>

Okay, it will be addressed.

>
> >
> > static inline u16 npcm_i2c_get_index(struct npcm_i2c *bus)
> > @@ -564,6 +564,15 @@ static inline void npcm_i2c_nack(struct npcm_i2c *bus)
> > iowrite8(val, bus->reg + NPCM_I2CCTL1);
> > }
> >
> > +static inline void npcm_i2c_clear_master_status(struct npcm_i2c *bus)
> > +{
> > + u8 val;
> > +
> > + /* Clear NEGACK, STASTR and BER bits */
> > + val = NPCM_I2CST_BER | NPCM_I2CST_NEGACK | NPCM_I2CST_STASTR;
> > + iowrite8(val, bus->reg + NPCM_I2CST);
>
> Small nitpick: Please keep the order the same between comment and code,
> e.g.:
>
> /* Clear BER, NEGACK and STASTR bits */
> val = NPCM_I2CST_BER | NPCM_I2CST_NEGACK | NPCM_I2CST_STASTR;
>
>
>
> Best regards,
> Jonathan


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