Am 2021-04-16 05:24, schrieb Benjamin Herrenschmidt:
On Mon, 2021-04-12 at 19:47 +0200, Michael Walle wrote:
/**
* of_get_phy_mode - Get phy mode for given device_node
@@ -59,15 +60,39 @@ static int of_get_mac_addr(struct device_node *np,
const char *name, u8 *addr)
static int of_get_mac_addr_nvmem(struct device_node *np, u8 *addr)
{
struct platform_device *pdev = of_find_device_by_node(np);
+ struct nvmem_cell *cell;
+ const void *mac;
+ size_t len;
int ret;
- if (!pdev)
- return -ENODEV;
+ /* Try lookup by device first, there might be a
nvmem_cell_lookup
+ * associated with a given device.
+ */
+ if (pdev) {
+ ret = nvmem_get_mac_address(&pdev->dev, addr);
+ put_device(&pdev->dev);
+ return ret;
+ }
+
This smells like the wrong band aid :)
Any struct device can contain an OF node pointer these days.
But not all nodes might have an associated device, see DSA for example.
And as the name suggests of_get_mac_address() operates on a node. So
if a driver calls of_get_mac_address() it should work on the node. What
is wrong IMHO, is that the ethernet drivers where the corresponding
board
has a nvmem_cell_lookup registered is calling of_get_mac_address(node).
It should rather call eth_get_mac_address(dev) in the first place.
One would need to figure out if there is an actual device (with an
assiciated of_node), then call eth_get_mac_address(dev) and if there
isn't a device call of_get_mac_address(node).
But I don't know if that is easy to figure out. Well, one could start
with just the device where nvmem_cell_lookup is used. Then we could
drop the workaround above.
This seems all backwards. I think we are dealing with bad evolution.
We need to do a lookup for the device because we get passed an of_node.
We should just get passed a device here... or rather stop calling
of_get_mac_addr() from all those drivers and instead call
eth_platform_get_mac_address() which in turns calls of_get_mac_addr().
Then the nvmem stuff gets put in eth_platform_get_mac_address().
of_get_mac_addr() becomes a low-level thingy that most drivers don't
care about.
The NVMEM thing is just another (optional) way how the MAC address
is fetched from the device tree. Thus, if the drivers have the
of_get_mac_address() call they should automatically get the NVMEM
method, too.
-michael
