On Tue, Jan 23, 2024 at 01:42:03AM +0000, Peng Fan wrote:
> Hi Sascha,
>
> > Subject: Re: [PATCH v2 2/3] mailbox: imx: get RR/TR registers num from
> > Parameter register
> >
> > Hi Peng,
>
> [snip]
> >
> > > };
> > >
> > > enum imx_mu_type {
> > > @@ -264,18 +267,17 @@ static int imx_mu_generic_rxdb(struct
> > > imx_mu_priv *priv, static int imx_mu_specific_tx(struct imx_mu_priv
> > > *priv, struct imx_mu_con_priv *cp, void *data) {
> > > u32 *arg = data;
> > > + u32 num_tr = priv->num_tr;
> > > int i, ret;
> > > u32 xsr;
> > > - u32 size, max_size, num_tr;
> > > + u32 size, max_size;
> > >
> > > if (priv->dcfg->type & IMX_MU_V2_S4) {
> > > size = ((struct imx_s4_rpc_msg_max *)data)->hdr.size;
> > > max_size = sizeof(struct imx_s4_rpc_msg_max);
> > > - num_tr = 8;
> >
> > This change looks unexpected here. num_tr used to be 8 here and now
> > becomes 4 at maximum. Was this a bug? If yes, this deserves a separate
> > patch with an explanation what was wrong here.
>
> Sorry, I could not follow you here.
> The num_tr is switch to use priv->num_tr now. It is not changed to 4 at
> maximum, it is just use priv->num_tr to avoid hardcoding it to 8.
> As of now, all platforms has IMX_MU_V2_S4 are using 8, and
> the hardware register num is 8, except i.MX95 V2X MU using 4.
I was confused by the warning you introduced:
> > > + if (priv->num_rr > 4 || priv->num_tr > 4) {
> > > + WARN_ONCE(true, "%s not support TR/RR larger than 4\n",
> > __func__);
> > > + return;
> > > + }
It will trigger when priv->num_tr is read as 8, so I assumed it is 4 at
maximum. Indeed just the check is wrong and you might haven't notice the
warning during testing.
Sascha
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