Re: [PATCH 4/5] i3c: master: svc return actual transfer data len

Frank Li
2023-10-18T20:26:26Z

On Tue, Oct 17, 2023 at 04:10:07PM +0200, Miquel Raynal wrote:
> Hi Frank,
>
> Frank.Li@nxp.com wrote on Mon, 16 Oct 2023 11:46:31 -0400:
>
> > I3C allow devices early terminate data transfer. So set "actual" to
> > indicate how much data get by i3c_priv_xfer.
> >
> > Signed-off-by: Frank Li <Frank.Li@nxp.com>
> > ---
> > drivers/i3c/master/svc-i3c-master.c | 7 +++++++
> > 1 file changed, 7 insertions(+)
> >
> > diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
> > index 3570b709cf60..444825aafa6f 100644
> > --- a/drivers/i3c/master/svc-i3c-master.c
> > +++ b/drivers/i3c/master/svc-i3c-master.c
> > @@ -138,6 +138,7 @@ struct svc_i3c_cmd {
> > const void *out;
> > unsigned int len;
> > unsigned int actual_len;
> > + struct i3c_priv_xfer *xfer;
> > bool continued;
> > };
> >
> > @@ -1045,6 +1046,7 @@ static int svc_i3c_master_xfer(struct svc_i3c_master *master,
> >
> > if (readl(master->regs + SVC_I3C_MERRWARN) & SVC_I3C_MERRWARN_NACK) {
> > ret = -ENXIO;
> > + *actual_len = 0;
> > goto emit_stop;
> > }
> >
> > @@ -1062,6 +1064,7 @@ static int svc_i3c_master_xfer(struct svc_i3c_master *master,
> > */
> > if (SVC_I3C_MSTATUS_IBIWON(reg)) {
> > ret = -ENXIO;
> > + *actual_len = 0;
> > goto emit_stop;
> > }
> >
> > @@ -1157,6 +1160,9 @@ static void svc_i3c_master_start_xfer_locked(struct svc_i3c_master *master)
> > cmd->addr, cmd->in, cmd->out,
> > cmd->len, &cmd->actual_len,
> > cmd->continued);
> > + if (cmd->xfer)
> > + cmd->xfer->actual = cmd->actual_len;
>
> Just to be sure, wouldn't it be more natural to always fill cmd->xfer
> rather than checking it here?

cmd->xfer is NULL for i2c and ccc transfer. So need check it.
I will add comments here

Frank
>
> > +
> > if (ret)
> > break;
> > }
> > @@ -1344,6 +1350,7 @@ static int svc_i3c_master_priv_xfers(struct i3c_dev_desc *dev,
> > for (i = 0; i < nxfers; i++) {
> > struct svc_i3c_cmd *cmd = &xfer->cmds[i];
> >
> > + cmd->xfer = xfers + i;
>
> Please follow the same pattern as below: = &xfers[i]
>
> > cmd->addr = master->addrs[data->index];
> > cmd->rnw = xfers[i].rnw;
> > cmd->in = xfers[i].rnw ? xfers[i].data.in : NULL;
>
>
> Thanks,
> Miquèl