Re: [PATCH net-next 07/15] net: dsa: mt7530: do not run mt7530_setup_port5() if port 5 is disabled

Arınç ÜNAL
2023-12-02T08:46:53Z

Hi Simon.

On 21.11.2023 21:53, Simon Horman wrote:
> On Sat, Nov 18, 2023 at 03:31:57PM +0300, Arınç ÜNAL wrote:
>> There's no need to run all the code on mt7530_setup_port5() if port 5 is
>> disabled. The only case for calling mt7530_setup_port5() from
>> mt7530_setup() is when PHY muxing is enabled. That is because port 5 is not
>> defined as a port on the devicetree, therefore, it cannot be controlled by
>> phylink.
>>
>> Because of this, run mt7530_setup_port5() if priv->p5_intf_sel is
>> P5_INTF_SEL_PHY_P0 or P5_INTF_SEL_PHY_P4. Remove the P5_DISABLED case from
>> mt7530_setup_port5().
>>
>> Stop initialising the interface variable as the remaining cases will always
>> call mt7530_setup_port5() with it initialised.
>>
>> Signed-off-by: Arınç ÜNAL <arinc.unal@arinc9.com>
>> Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
>> ---
>> drivers/net/dsa/mt7530.c | 9 +++------
>> 1 file changed, 3 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
>> index fc87ec817672..1aab4c3f28b0 100644
>> --- a/drivers/net/dsa/mt7530.c
>> +++ b/drivers/net/dsa/mt7530.c
>> @@ -942,9 +942,6 @@ static void mt7530_setup_port5(struct dsa_switch *ds, phy_interface_t interface)
>> /* MT7530_P5_MODE_GMAC: P5 -> External phy or 2nd GMAC */
>> val &= ~MHWTRAP_P5_DIS;
>> break;
>> - case P5_DISABLED:
>> - interface = PHY_INTERFACE_MODE_NA;
>> - break;
>> default:
>> dev_err(ds->dev, "Unsupported p5_intf_sel %d\n",
>> priv->p5_intf_sel);
>> @@ -2313,8 +2310,6 @@ mt7530_setup(struct dsa_switch *ds)
>> * Set priv->p5_intf_sel to the appropriate value if PHY muxing
>> * is detected.
>> */
>> - interface = PHY_INTERFACE_MODE_NA;
>> -
>> for_each_child_of_node(dn, mac_np) {
>> if (!of_device_is_compatible(mac_np,
>> "mediatek,eth-mac"))
>> @@ -2346,7 +2341,9 @@ mt7530_setup(struct dsa_switch *ds)
>> break;
>> }
>>
>> - mt7530_setup_port5(ds, interface);
>> + if (priv->p5_intf_sel == P5_INTF_SEL_PHY_P0 ||
>> + priv->p5_intf_sel == P5_INTF_SEL_PHY_P4)
>> + mt7530_setup_port5(ds, interface);
>
> Hi Arınç,
>
> It appears that interface is now uninitialised here.
>
> Flagged by Smatch.

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);

Arınç