Re: [PATCH 3/6] i3c: master: svc: fix ibi may not return mandatory data byte

Frank Li
2023-10-17T20:56:00Z

On Tue, Oct 17, 2023 at 04:27:07PM +0200, Miquel Raynal wrote:
> Hi Frank,
>
> Frank.Li@nxp.com wrote on Mon, 16 Oct 2023 11:32:29 -0400:
>
> > MSTATUS[RXPEND] is only updated after the data transfer cycle started. This
> > creates an issue when the I3C clock is slow, and the CPU is running fast
> > enough that MSTATUS[RXPEND] may not be updated when the code reach checking
> > point. As a result, mandatory data are being missed.
>
> can be missed.
>
> > Add a wait for MSTATUS[COMPLETE] to ensure that all mandatory data already
> > in FIFO.
>
> is already in the FIFO
>
> >
> > Fixes: dd3c52846d59 ("i3c: master: svc: Add Silvaco I3C master driver")
> > Cc: stable@vger.kernel.org
> > Signed-off-by: Frank Li <Frank.Li@nxp.com>
> > ---
> > drivers/i3c/master/svc-i3c-master.c | 8 ++++++++
> > 1 file changed, 8 insertions(+)
> >
> > diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
> > index 0f57a5f75e39..c252446b2bc5 100644
> > --- a/drivers/i3c/master/svc-i3c-master.c
> > +++ b/drivers/i3c/master/svc-i3c-master.c
> > @@ -331,6 +331,7 @@ static int svc_i3c_master_handle_ibi(struct svc_i3c_master *master,
> > struct i3c_ibi_slot *slot;
> > unsigned int count;
> > u32 mdatactrl;
> > + int ret, val;
> > u8 *buf;
> >
> > slot = i3c_generic_ibi_get_free_slot(data->ibi_pool);
> > @@ -340,6 +341,13 @@ static int svc_i3c_master_handle_ibi(struct svc_i3c_master *master,
> > slot->len = 0;
> > buf = slot->data;
> >
> > + ret = readl_relaxed_poll_timeout(master->regs + SVC_I3C_MSTATUS, val,
> > + SVC_I3C_MSTATUS_COMPLETE(val), 0, 1000);
>
> Are you sure !MSTATUS_COMPLETE(val) is never a valid condition?
> Especially with non-mandatory bytes?
>
> Also, are you sure of the indentation here?

If no-mandatory data, it is equal RDTERAM is 0. It takes some times to
change my slave code to create such test case.

Frank Li

>
> > + if (ret) {
> > + dev_err(master->dev, "Timeout when polling for COMPLETE\n");
> > + return ret;
> > + }
> > +
> > while (SVC_I3C_MSTATUS_RXPEND(readl(master->regs + SVC_I3C_MSTATUS)) &&
> > slot->len < SVC_I3C_FIFO_SIZE) {
> > mdatactrl = readl(master->regs + SVC_I3C_MDATACTRL);
>
>
> Thanks,
> Miquèl