Re: [PATCH v2 2/3] net: add support for nvmem to eth_platform_get_mac_address()
From: Dan Carpenter <hidden>
Date: 2018-07-19 08:50:40
Also in:
linux-arm-kernel, linux-omap, lkml
On Thu, Jul 19, 2018 at 10:20:27AM +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 | 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