[PATCH 4/5] net: add support for nvmem to eth_platform_get_mac_address()
From: andrew@lunn.ch (Andrew Lunn)
Date: 2018-07-19 15:22:52
Also in:
linux-omap, lkml, netdev
On Wed, Jul 18, 2018 at 06:10:34PM +0200, Bartosz Golaszewski wrote:
quoted hunk ↗ jump to hunk
From: Bartosz Golaszewski <redacted> 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 <redacted> --- net/ethernet/eth.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+)diff --git a/net/ethernet/eth.c b/net/ethernet/eth.c index 6b64586fd2af..adf5bd03851f 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>@@ -530,7 +531,10 @@ int eth_platform_get_mac_address(struct device *dev, u8 *mac_addr) struct device_node *dp = dev_is_pci(dev) ? pci_device_to_OF_node(to_pci_dev(dev)) : dev->of_node; const unsigned char *addr = NULL; + unsigned char addrbuf[ETH_ALEN]; + struct nvmem_cell *nvmem; const char *from = NULL; + size_t alen; if (dp) { addr = of_get_mac_address(dp);@@ -544,6 +548,31 @@ int eth_platform_get_mac_address(struct device *dev, u8 *mac_addr) from = "arch callback"; } + if (!addr) { + nvmem = nvmem_cell_get(dev, "mac-address"); + if (IS_ERR(nvmem) && PTR_ERR(nvmem) == -EPROBE_DEFER)
How does EPROBE_DEFER work here? You say the use case is Non-DT. Without having DT, how do you know the cell should exist, but does not yet exist? I might be looking at old code, but i only see -EPROBE_DEFER inside the if (np) case.
+ /* We may have a lookup registered for MAC address but + * the corresponding nvmem provider hasn't been + * registered yet. + */ + return -EPROBE_DEFER;
You really should return real errors. If i'm reading
__nvmem_device_get() right, it will return a NULL pointer when the
cell does not exist. NULL is not an error, so IS_ERR() will return
false. So you should return all errors from nvmem_cell_get().
Andrew