Dell systems with Type-C ports have support for a persistent system specific MAC address when used with Dell Type-C docks and dongles. This means a dock plugged into two different systems will show different (but persistent) MAC addresses. Dell Type-C docks and dongles use the r8152 driver.
This information for the system's persistent MAC address is burned in when the HW is built and avilable under _SB\AMAC in the DSDT at runtime. More information about the technology is available here: http://www.dell.com/support/article/us/en/04/SLN301147 Signed-off-by: Mario Limonciello <mario_limoncie...@dell.com> --- drivers/net/usb/Kconfig | 1 + drivers/net/usb/r8152.c | 37 +++++++++++++++++++++++++++++++++++++ 2 files changed, 38 insertions(+) diff --git a/drivers/net/usb/Kconfig b/drivers/net/usb/Kconfig index cdde590..c320930 100644 --- a/drivers/net/usb/Kconfig +++ b/drivers/net/usb/Kconfig @@ -98,6 +98,7 @@ config USB_RTL8150 config USB_RTL8152 tristate "Realtek RTL8152/RTL8153 Based USB Ethernet Adapters" select MII + depends on ACPI help This option adds support for Realtek RTL8152 based USB 2.0 10/100 Ethernet adapters and RTL8153 based USB 3.0 10/100/1000 diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c index 3f9f6ed..62af3b4 100644 --- a/drivers/net/usb/r8152.c +++ b/drivers/net/usb/r8152.c @@ -26,6 +26,7 @@ #include <linux/mdio.h> #include <linux/usb/cdc.h> #include <linux/suspend.h> +#include <linux/acpi.h> /* Information for net-next */ #define NETNEXT_VERSION "08" @@ -1030,6 +1031,39 @@ out1: return ret; } +static u8 amac_ascii_to_hex(int c) +{ + if (c <= 0x39) + return (u8)(c - 0x30); + else if (c <= 0x46) + return (u8)(c - 0x37); + return (u8)(c - 0x57); +} + +static void set_auxiliary_addr(struct sockaddr *sa) +{ + acpi_status status; + acpi_handle handle; + struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; + union acpi_object *obj; + int i; + char *ptr; + + acpi_get_handle(NULL, "\\_SB", &handle); + status = acpi_evaluate_object(handle, "AMAC", NULL, &buffer); + obj = (union acpi_object *)buffer.pointer; + if (ACPI_SUCCESS(status) && (obj->string.length == 0x17)) { + /* returns _AUXMAC_#AABBCCDDEEFF# + * this pulls out _AUXMAC# from start and # from end + */ + ptr = obj->string.pointer + 9; + pr_info("r8152: Using system auxiliary MAC address"); + for (i = 0; i < 6; i++, ptr += 2) + sa->sa_data[i] = amac_ascii_to_hex(*ptr) << 4 | + amac_ascii_to_hex(*(ptr + 1)); + } +} + static int set_ethernet_addr(struct r8152 *tp) { struct net_device *dev = tp->netdev; @@ -1041,6 +1075,9 @@ static int set_ethernet_addr(struct r8152 *tp) else ret = pla_ocp_read(tp, PLA_BACKUP, 8, sa.sa_data); + /* if system provides auxiliary MAC address */ + set_auxiliary_addr(&sa); + if (ret < 0) { netif_err(tp, probe, dev, "Get ether addr fail\n"); } else if (!is_valid_ether_addr(sa.sa_data)) { -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
