Re: [PATCH v11] i2c: designware: fix controller is holding SCL low while ENABLE bit is disabled

From: Andi Shyti
Date: Fri Sep 13 2024 - 04:52:53 EST


Hi Kimriver,

please, don't send v12 anymore, I will take care of these little
notes from Andy.

You did a great job at following up on all the reviews, thanks!

Andi

On Fri, Sep 13, 2024 at 08:31:18AM GMT, Liu Kimriver/刘金河 wrote:
> Hi Andy
>
> Subject: [PATCH v11] i2c: designware: fix controller is holding SCL low while ENABLE bit is disabled
> I will change the subject to:
> Subject: [PATCH v11] i2c: designware: fix controller is holding SCL low while the ENABLE bit is disabled
>
> >-----Original Message-----
> >From: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
> >Sent: 2024年9月13日 15:41
> >To: Liu Kimriver/刘金河 <kimriver.liu@xxxxxxxxxxxx>
> >Cc: jarkko.nikula@xxxxxxxxxxxxxxx; andriy.shevchenko@xxxxxxxxxxxxxxx; mika.westerberg@xxxxxxxxxxxxxxx; jsd@xxxxxxxxxxxx; andi.shyti@xxxxxxxxxx; linux-i2c@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Andy >Shevchenko <andy@xxxxxxxxxx>
> >Subject: Re: [PATCH v11] i2c: designware: fix controller is holding SCL low while ENABLE bit is disabled
>
> >On Fri, Sep 13, 2024 at 6:35 AM Kimriver Liu <kimriver.liu@xxxxxxxxxxxx> wrote:
> >>
> >> It was observed that issuing the ABORT bit (IC_ENABLE[1]) will not
> >> work when IC_ENABLE is already disabled.
> >>
> >> Check if the ENABLE bit (IC_ENABLE[0]) is disabled when the controller
> >> is holding SCL low. If the ENABLE bit is disabled, the software needs
> >> to enable it before trying to issue the ABORT bit. otherwise, the
> >> controller ignores any write to ABORT bit.
> >>
> >> These kernel logs show up whenever an I2C transaction is attempted
> >> after this failure.
> >> i2c_designware e95e0000.i2c: timeout waiting for bus ready
> >> i2c_designware e95e0000.i2c: timeout in disabling adapter
> >>
> >> The patch fixes the issue where the controller cannot be disabled
> >> while SCL is held low if the ENABLE bit is already disabled.
> >
> >...
> >
> >> + /*Set ENABLE bit before setting ABORT*/
>
> /* Set ENABLE bit before setting ABORT */
>
> >Missing spaces
> >
> >...
>
> >> +/*
> >> + * This function waits controller idling before disabling I2C
>
> >waits for controller
>
> + * This function waits for controller idling before disabling I2C
>
> >> + * When the controller is not in the IDLE state,
> >> + * MST_ACTIVITY bit (IC_STATUS[5]) is set.
> >> + * Values:
> >> + * 0x1 (ACTIVE): Controller not idle
> >> + * 0x0 (IDLE): Controller is idle
> >> + * The function is called after returning the end of the current
> >> + transfer
> >> + * Returns:
>
> >> + * False when controller is in IDLE state.
> >> + * True when controller is in ACTIVE state.
>
> >Yeah, I know that this is a copy of what I suggested, but if we going to amend, these should be with definite article
>
> > * False when the controller is in the IDLE state.
> > * True when the controller is in the ACTIVE state.
>
>
>
> >> + */
>
> >...
>
> >> + return regmap_read_poll_timeout(dev->map, DW_IC_STATUS, status,
> >> + !(status & DW_IC_STATUS_MASTER_ACTIVITY),
> >> + 1100, 20000) != 0;
>
> >You broke the indentation again.
>
> it has been indented and aligned from the web:
> https://lore.kernel.org/all/4ebc4e8882a52620cbca30f1bf25650cbc3723fb.1726197817.git.kimriver.liu@xxxxxxxxxxxx/
>
> Thanks!
>
> >--
> ------------------------------------------
> Best Regards
> Kimriver Liu