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 -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |