Re: [RESEND PATCH v2] soc: mediatek: PMIC wrap: Clear the vldclr if state machine stay on FSM_VLDCLR state.

[Matthias Brugger]

On 08/01/16 03:43, Ricky Liang wrote:
> On Mon, Jan 4, 2016 at 8:02 PM, Henry Chen <henryc.chen@xxxxxxxxxxxx> 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 beginning of the
> > read/write function.
> >
> > Clear the vldclr when timeout if state machine stay on FSM_VLDCLR.
> >
> > Signed-off-by: Henry Chen <henryc.chen@xxxxxxxxxxxx>
> > ---
> > Changes since v1:
> > Encapsulated the code in a inline function, and add a descriptive comment.
> > ---
> >   drivers/soc/mediatek/mtk-pmic-wrap.c | 30 ++++++++++++++++++++++++++++--
> >   1 file changed, 28 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/soc/mediatek/mtk-pmic-wrap.c b/drivers/soc/mediatek/mtk-pmic-wrap.c
> > index 105597a..af919b1 100644
> > --- a/drivers/soc/mediatek/mtk-pmic-wrap.c
> > +++ b/drivers/soc/mediatek/mtk-pmic-wrap.c
> > @@ -412,6 +412,12 @@ static bool pwrap_is_fsm_vldclr(struct pmic_wrapper *wrp)
> >          return PWRAP_GET_WACS_FSM(val) == PWRAP_WACS_FSM_WFVLDCLR;
> >   }
> >
> > +static inline void pwrap_leave_fsm_vldclr(struct pmic_wrapper *wrp)
> > +{
> > +       if (pwrap_is_fsm_vldclr(wrp))
> > +               pwrap_writel(wrp, 1, PWRAP_WACS2_VLDCLR);
> > +}
> > +
> >   static bool pwrap_is_sync_idle(struct pmic_wrapper *wrp)
> >   {
> >          return pwrap_readl(wrp, PWRAP_WACS2_RDATA) & PWRAP_STATE_SYNC_IDLE0;
> > @@ -445,8 +451,18 @@ static int pwrap_write(struct pmic_wrapper *wrp, u32 adr, u32 wdata)
> >          int ret;
> >
> >          ret = pwrap_wait_for_state(wrp, pwrap_is_fsm_idle);
> > -       if (ret)
> > +       if (ret) {
> > +               /*
> > +                * Timeout issue sometimes caused by the last read command
> > +                * failed because pmic wrap could not got the FSM_VLDCLR
> > +                * in time after finishing WACS2_CMD. It made state machine
> > +                * still on FSM_VLDCLR and timeout next time.
> > +                * Check the status of FSM and clear the vldclr to recovery the
> > +                * error.
> > +                */
> > +               pwrap_leave_fsm_vldclr(wrp);
> >                  return ret;
> > +       }
> >
> >          pwrap_writel(wrp, (1 << 31) | ((adr >> 1) << 16) | wdata,
> >                          PWRAP_WACS2_CMD);
> > @@ -459,8 +475,18 @@ static int pwrap_read(struct pmic_wrapper *wrp, u32 adr, u32 *rdata)
> >          int ret;
> >
> >          ret = pwrap_wait_for_state(wrp, pwrap_is_fsm_idle);
> > -       if (ret)
> > +       if (ret) {
> > +               /*
> > +                * Timeout issue sometimes caused by the last read command
> > +                * failed because pmic wrap could not got the FSM_VLDCLR
> > +                * in time after finishing WACS2_CMD. It made state machine
> > +                * still on FSM_VLDCLR and timeout next time.
> > +                * Check the status of FSM and clear the vldclr to recovery the
> > +                * error.
> > +                */
> > +               pwrap_leave_fsm_vldclr(wrp);
> >                  return ret;
> > +       }
> >
> >          pwrap_writel(wrp, (adr >> 1) << 16, PWRAP_WACS2_CMD);
> >
> > --
> > 1.9.1
> >
> > --
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>
>
> Tested-by: Ricky Liang <jcliang@xxxxxxxxxxxx>
>
> On our test platform this patch fixes PMIC communication erros.

I put the comment above the function declaration.

Applied to v4.5-next/soc

Thanks.