Re: [PATCH] soc: mediatek: PMIC wrap: Clear the vldclr if state machine is stay on FSM_VLDCLR state.

[Matthias Brugger]

On 31/12/15 03:09, Henry Chen wrote:
> Hi Matthias,
>
> On Wed, 2015-12-30 at 19:02 +0100, Matthias Brugger wrote:
> > On 22/12/15 08:51, Henry Chen wrote:
> > > Sometimes PMIC is too busy to send data in time to cause pmic wrap timeout,
> > > because pmic wrap is waiting for FSM_VLDCLR after finishing WACS2_CMD. It
> > > just return error when issue happened, so the state machine will stay on
> > > FSM_VLDCLR state when data send back later by PMIC and timeout again in next
> > > time because pmic wrap waiting for FSM_IDLE state at the begining of the
> > > read/write function.
> > >
> > > Clear the vldclr when timeout if state machine is stay on FSM_VLDCLR.
> > >
> > > Signed-off-by: Henry Chen <henryc.chen@xxxxxxxxxxxx>
> > > ---
> > >    drivers/soc/mediatek/mtk-pmic-wrap.c | 16 ++++++++++++++--
> > >    1 file changed, 14 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/drivers/soc/mediatek/mtk-pmic-wrap.c b/drivers/soc/mediatek/mtk-pmic-wrap.c
> > > index 105597a..ccd5337 100644
> > > --- a/drivers/soc/mediatek/mtk-pmic-wrap.c
> > > +++ b/drivers/soc/mediatek/mtk-pmic-wrap.c
> > > @@ -443,10 +443,16 @@ static int pwrap_wait_for_state(struct pmic_wrapper *wrp,
> > >    static int pwrap_write(struct pmic_wrapper *wrp, u32 adr, u32 wdata)
> > >    {
> > >    	int ret;
> > > +	u32 val;
> > >
> > >    	ret = pwrap_wait_for_state(wrp, pwrap_is_fsm_idle);
> > > -	if (ret)
> > > +	if (ret) {
> > > +		/* Clear vldclr bit if state is on the WACS_FSM_WFVLDCLR */
> > > +		val = pwrap_readl(wrp, PWRAP_WACS2_RDATA);
> > > +		if (PWRAP_GET_WACS_FSM(val) == PWRAP_WACS_FSM_WFVLDCLR)
> > > +			pwrap_writel(wrp, 1, PWRAP_WACS2_VLDCLR);
> > >    		return ret;
> > > +	}
> >
> > I would prefer to have this encapsulated in a (inline) function. Maybe
> > with better description then just the one line comment.
> >
> > Thanks,
> > Matthias
>
> Ok, I will make the description more clear, do you means write the
> function like below and used it on pwrap_write/pwrap_read.
>
> static inline void pwrap_leave_fsm_vldclr(struct pmic_wrapper *wrp)
> {
> 	if (pwrap_is_fsm_vldclr(wrp))
> 		pwrap_writel(wrp, 1, PWRAP_WACS2_VLDCLR);
> }

I didn't remind of pwrap_is_fsm_vldclr neither, nice.
Yes please use this function and add a descriptive comment on the top, 
so that in the future it is clear what is happening here.

Thanks,
Matthias

> Thanks,
> Henry
>
> > >    	pwrap_writel(wrp, (1 << 31) | ((adr >> 1) << 16) | wdata,
> > >    			PWRAP_WACS2_CMD);
> > > @@ -457,10 +463,16 @@ static int pwrap_write(struct pmic_wrapper *wrp, u32 adr, u32 wdata)
> > >    static int pwrap_read(struct pmic_wrapper *wrp, u32 adr, u32 *rdata)
> > >    {
> > >    	int ret;
> > > +	u32 val;
> > >
> > >    	ret = pwrap_wait_for_state(wrp, pwrap_is_fsm_idle);
> > > -	if (ret)
> > > +	if (ret) {
> > > +		/* Clear vldclr bit if state is on the WACS_FSM_WFVLDCLR */
> > > +		val = pwrap_readl(wrp, PWRAP_WACS2_RDATA);
> > > +		if (PWRAP_GET_WACS_FSM(val) == PWRAP_WACS_FSM_WFVLDCLR)
> > > +			pwrap_writel(wrp, 1, PWRAP_WACS2_VLDCLR);
> > >    		return ret;
> > > +	}
> > >
> > >    	pwrap_writel(wrp, (adr >> 1) << 16, PWRAP_WACS2_CMD);
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