Re: [PATCH] net: dsa: fix filling rtable from OF description

From: Andrew Lunn
Date: Sat Apr 04 2015 - 12:42:39 EST

Hi Pavel

There is the code after applying your patch:

static int dsa_of_setup_routing_table(struct dsa_platform_data *pd,
struct dsa_chip_data *cd,
int chip_index, int port_index,
struct device_node *link)
const __be32 *reg;
int link_sw_addr;
struct device_node *parent_sw;
int len;

parent_sw = of_get_parent(link);
if (!parent_sw)
return -EINVAL;

link is the phandle to the port in other switch. parent_sw is then the
switch property.

reg = of_get_property(parent_sw, "reg", &len);
if (!reg || (len != sizeof(*reg) * 2))
return -EINVAL;

So now you get the reg property. This is documented as:

- reg : Describes the switch address on the MII bus

link_sw_addr = be32_to_cpup(reg + 1);

if (link_sw_addr >= pd->nr_chips)
return -EINVAL;

This is now not making much sense.

Looking up the MII bus address seems wrong. You want the chip number,
not its address.


/* First time routing table allocation */
if (!cd->rtable) {
cd->rtable = kmalloc_array(pd->nr_chips, sizeof(s8),
if (!cd->rtable)
return -ENOMEM;

/* default to no valid uplink/downlink */
memset(cd->rtable, -1, pd->nr_chips * sizeof(s8));

cd->rtable[link_sw_addr] = port_index;

return 0;

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