Messages in this thread | | | Subject | Re: [PATCH 1/1] r8169: revert "read MAC address from EEPROM on init" | From | Krzysztof Halasa <> | Date | Mon, 27 Oct 2008 23:29:59 +0100 |
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[Reposting to lkml only, Gnus likes to eat quoting from email addresses under specific circumstances and then vger doesn't pass them through]
Francois Romieu <romieu@fr.zoreil.com> writes:
> -static int rtl_eeprom_read(struct pci_dev *pdev, int cap, int addr, __le32 *val) > -{ > - int ret, count = 100; > - u16 status = 0; > - u32 value; > - > - ret = pci_write_config_word(pdev, cap + PCI_VPD_ADDR, addr); > - if (ret < 0) > - return ret; > - > - do { > - udelay(10); > - ret = pci_read_config_word(pdev, cap + PCI_VPD_ADDR, &status); > - if (ret < 0) > - return ret; > - } while (!(status & PCI_VPD_ADDR_F) && --count); > - > - if (!(status & PCI_VPD_ADDR_F)) > - return -ETIMEDOUT; > - > - ret = pci_read_config_dword(pdev, cap + PCI_VPD_DATA, &value); > - if (ret < 0) > - return ret; > - > - *val = cpu_to_le32(value); > - > - return 0;
Ahh, just PCI VPD.
IMHO the above shouldn't hurt anyone, in theory. You only write to VPD_ADDR, and to change actual VPD data (i.e., EEPROM), you need to write to VPD_DATA.
Anyone should be allowed to do that even for unknown PCI devices without a problem.
> -static void rtl_init_mac_address(struct rtl8169_private *tp,
> - if (!(cfg1 & VPD)) { > - if (netif_msg_probe(tp)) > - dev_info(&pdev->dev, "VPD access disabled, enabling\n"); > - RTL_W8(Cfg9346, Cfg9346_Unlock); > - RTL_W8(Config1, cfg1 | VPD); > - RTL_W8(Cfg9346, Cfg9346_Lock);
Now I wonder what do they say the above does exactly. Unfortunately the docs don't seem to be public.
> - * MAC address is stored in EEPROM at offset 0x0e > - * Realtek says: "The VPD address does not have to be a DWORD-aligned > - * address as defined in the PCI 2.2 Specifications, but the VPD data > - * is always consecutive 4-byte data starting from the VPD address > - * specified."
Nice.
> - if (netif_msg_probe(tp)) { > - DECLARE_MAC_BUF(buf); > - > - dev_info(&pdev->dev, "MAC address found in EEPROM: %s\n", > - print_mac(buf, mac)); > - } > - > - if (is_valid_ether_addr(mac)) > - rtl_rar_set(tp, mac); > -}
No RTL_W8(Config1, cfg1 | ~VPD) to disable (perhaps R/W) access?
Though obviously first reading a good address from the EEPROM and then erasing first 32 bits is a different story. I wonder if changing the MAC address by hand works (using ifconfig, to arbitrary address).
-- Krzysztof Halasa
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