Re: [PATCH 5/5] net: add MTD support to eth_platform_get_mac_address()

[Andrew Lunn]

On Wed, Jul 18, 2018 at 06:10:35PM +0200, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
> 
> MTD doesn't support nvmem yet. Some platforms use MTD to read the MAC
> address from SPI flash. If we want this function to generalize reading
> the MAC address, we need to separately try to use MTD.
> 
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
> ---
>  net/ethernet/eth.c | 20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)
> 
> diff --git a/net/ethernet/eth.c b/net/ethernet/eth.c
> index adf5bd03851f..f7dbd2cff7f9 100644
> --- a/net/ethernet/eth.c
> +++ b/net/ethernet/eth.c
> @@ -55,6 +55,7 @@
>  #include <linux/of_net.h>
>  #include <linux/pci.h>
>  #include <linux/nvmem-consumer.h>
> +#include <linux/mtd/mtd.h>
>  #include <net/dst.h>
>  #include <net/arp.h>
>  #include <net/sock.h>
> @@ -573,6 +574,25 @@ int eth_platform_get_mac_address(struct device *dev, u8 *mac_addr)
>  		}
>  	}
>  
> +#ifdef CONFIG_MTD
> +	/* NOTE: this should go away as soon as MTD gets nvmem support. */
> +	if (!addr) {
> +		struct mtd_info *mtd;
> +		int rv;
> +
> +		mtd = get_mtd_device_nm("MAC-Address");

In order for this to go away, you need to keep backwards
compatibility. When using nvmem, you look for a cell called
"mac-address". Here you are looking for "MAC-Address". That is going
to make backwards compatibility harder. How do you plan to do it?

   Andrew