Messages in this thread | | | Date | Thu, 7 Dec 2023 09:51:07 +0300 | From | Dan Carpenter <> | Subject | Re: [PATCH net-next 07/15] net: dsa: mt7530: do not run mt7530_setup_port5() if port 5 is disabled |
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On Sat, Dec 02, 2023 at 11:45:42AM +0300, Arınç ÜNAL wrote: > > I'm not sure why it doesn't catch that for mt7530_setup_port5() to run > here, priv->p5_intf_sel must be either P5_INTF_SEL_PHY_P0 or > P5_INTF_SEL_PHY_P4. And for that to happen, the interface variable will be > initialised. > > for_each_child_of_node(dn, mac_np) { > if (!of_device_is_compatible(mac_np, > "mediatek,eth-mac")) > continue; > > ret = of_property_read_u32(mac_np, "reg", &id); > if (ret < 0 || id != 1) > continue; > > phy_node = of_parse_phandle(mac_np, "phy-handle", 0); > if (!phy_node) > continue; > > if (phy_node->parent == priv->dev->of_node->parent) { > ret = of_get_phy_mode(mac_np, &interface); > if (ret && ret != -ENODEV) { > of_node_put(mac_np); > of_node_put(phy_node); > return ret; > } > id = of_mdio_parse_addr(ds->dev, phy_node); > if (id == 0) > priv->p5_intf_sel = P5_INTF_SEL_PHY_P0; > if (id == 4) > priv->p5_intf_sel = P5_INTF_SEL_PHY_P4; > } > of_node_put(mac_np); > of_node_put(phy_node); > break; > } > > if (priv->p5_intf_sel == P5_INTF_SEL_PHY_P0 || > priv->p5_intf_sel == P5_INTF_SEL_PHY_P4) > mt7530_setup_port5(ds, interface);
Smatch doesn't know: 1) What the value of priv->p5_intf_sel is going into this function 2) We enter the for_each_child_of_node() loop 3) That if (phy_node->parent == priv->dev->of_node->parent) { is definitely true for one element on the list.
Looking at how Smatch parses this code, I could probably improve problem #1 a bit. Right now Smatch sees "struct mt7530_priv *priv = ds->priv;" and "priv->p5_intf_sel" is unknown, but I could probably improve it to where it says that it's in the 1-3 range. But that doesn't help here and it doesn't address problems 2 and 3.
It's a hard problem.
regards, dan carpenter
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