Re: [PATCH v3 10/11] i3c: master: svc: wait for Manual ACK/NACK Done before next step

Frank Li
2024-08-23T16:46:08Z

On Fri, Aug 23, 2024 at 06:22:40PM +0200, Miquel Raynal wrote:
> Hi Frank,
>
> Frank.Li@nxp.com wrote on Mon, 19 Aug 2024 12:02:04 -0400:
>
> > Wait for the controller to complete emitting ACK/NACK, otherwise the next
> > command may be omitted by the hardware.
> >
> > Add command done check at svc_i3c_master_nack(ack)_ibi() and change return
>
> a "command done" check in
>
> the reutnr type
>
> > type to int to indicate wait done timeout.
>
> flag possible timeouts.
>
> >
> > Signed-off-by: Frank Li <Frank.Li@nxp.com>
> > ---
> > drivers/i3c/master/svc-i3c-master.c | 31 +++++++++++++++++++++++++------
> > 1 file changed, 25 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
> > index fbb6cef405577..2010495906eb3 100644
> > --- a/drivers/i3c/master/svc-i3c-master.c
> > +++ b/drivers/i3c/master/svc-i3c-master.c
> > @@ -384,10 +384,12 @@ static int svc_i3c_master_handle_ibi(struct svc_i3c_master *master,
> > return 0;
> > }
> >
> > -static void svc_i3c_master_ack_ibi(struct svc_i3c_master *master,
> > +static int svc_i3c_master_ack_ibi(struct svc_i3c_master *master,
> > bool mandatory_byte)
> > {
> > unsigned int ibi_ack_nack;
> > + int ret;
> > + u32 reg;
> >
> > ibi_ack_nack = SVC_I3C_MCTRL_REQUEST_IBI_ACKNACK;
> > if (mandatory_byte)
> > @@ -396,18 +398,31 @@ static void svc_i3c_master_ack_ibi(struct svc_i3c_master *master,
> > ibi_ack_nack |= SVC_I3C_MCTRL_IBIRESP_ACK_WITHOUT_BYTE;
> >
> > writel(ibi_ack_nack, master->regs + SVC_I3C_MCTRL);
> > +
> > + ret = readl_poll_timeout_atomic(master->regs + SVC_I3C_MSTATUS, reg,
> > + SVC_I3C_MSTATUS_MCTRLDONE(reg), 1, 1000);
>
> Still concerned about the _atomic.

It may be call in atomic context. Because hardware design limition, i3c
transact have been in irq disable context to avoid 100us timeout issue.

Frank

>
> > + return ret;
>
> return readl...
>
> > +
> > }
>
> Otherwise LGTM
>
> Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
>
> Thanks,
> Miquèl