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

Miquel Raynal
2023-10-17T14:10:18Z

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?

> +
> 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