On Thu, Jul 19, 2018 at 10:20:27AM +0200, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
>
> Many non-DT platforms read the MAC address from EEPROM. Usually it's
> either done with callbacks defined in board files or from SoC-specific
> ethernet drivers.
>
> In order to generalize this, try to read the MAC from nvmem in
> eth_platform_get_mac_address() using a standard lookup name:
> "mac-address".
>
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
> ---
> net/ethernet/eth.c | 27 +++++++++++++++++++++++++++
> 1 file changed, 27 insertions(+)
>
> diff --git a/net/ethernet/eth.c b/net/ethernet/eth.c
> index 39af03894598..af3b4b1b77eb 100644
> --- a/net/ethernet/eth.c
> +++ b/net/ethernet/eth.c
> @@ -54,6 +54,7 @@
> #include <linux/if_ether.h>
> #include <linux/of_net.h>
> #include <linux/pci.h>
> +#include <linux/nvmem-consumer.h>
> #include <net/dst.h>
> #include <net/arp.h>
> #include <net/sock.h>
> @@ -527,8 +528,11 @@ unsigned char * __weak arch_get_platform_mac_address(void)
>
> int eth_platform_get_mac_address(struct device *dev, u8 *mac_addr)
> {
> + unsigned char addrbuf[ETH_ALEN];
> const unsigned char *addr;
> + struct nvmem_cell *nvmem;
> struct device_node *dp;
> + size_t alen;
>
> if (dev_is_pci(dev))
> dp = pci_device_to_OF_node(to_pci_dev(dev));
> @@ -541,6 +545,29 @@ int eth_platform_get_mac_address(struct device *dev, u8 *mac_addr)
> if (!addr)
> addr = arch_get_platform_mac_address();
>
> + if (!addr) {
> + nvmem = nvmem_cell_get(dev, "mac-address");
> + if (IS_ERR(nvmem) && PTR_ERR(nvmem) == -EPROBE_DEFER)
> + /* We may have a lookup registered for MAC address but
> + * the corresponding nvmem provider hasn't been
> + * registered yet.
> + */
> + return -EPROBE_DEFER;
> +
> + if (!IS_ERR(nvmem)) {
> + addr = nvmem_cell_read(nvmem, &alen);
> + if (!IS_ERR(addr)) {
^^^^
Never do success handling. Always error handling. Otherwise the code
is indent a lot and the error handling is far from the call.
> + if (alen == ETH_ALEN)
> + ether_addr_copy(addrbuf, addr);
> +
> + kfree(addr);
> + addr = alen == ETH_ALEN ? addrbuf : NULL;
> + }
> +
> + nvmem_cell_put(nvmem);
> + }
> + }
> +
> if (!addr || !is_valid_ether_addr(addr))
^^^^
Instead of handling the error we dereference the error pointer here.
*frowny face*
> return -ENODEV;
>
> --
Maybe this?
if (!addr) {
nvmem = nvmem_cell_get(dev, "mac-address");
if (PTR_ERR(nvmem) == -EPROBE_DEFER)
return -EPROBE_DEFER;
if (IS_ERR(nvmem))
return -ENODEV;
addr = nvmem_cell_read(nvmem, &alen);
if (IS_ERR(addr))
return PTR_ERR(addr);
if (alen != ETH_ALEN) {
kfree(addr);
return -ENODEV;
}
ether_addr_copy(addrbuf, addr);
kfree(addr);
addr = addrbuf;
}
if (!is_valid_ether_addr(addr))
return -ENODEV;
ether_addr_copy(mac_addr, addr);
return 0;
regards,
dan carpenter
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