Re: [PATCH] r8169: Load MAC address from device tree if present

Heiner Kallweit
2019-01-25T18:26:52Z

On 25.01.2019 15:57, Andrew Lunn wrote:
> On Fri, Jan 25, 2019 at 11:18:14AM +0100, Thierry Reding wrote:
>> From: Thierry Reding <treding@nvidia.com>
>>
>> If the system was booted using a device tree and if the device tree
>> contains a MAC address, use it instead of reading one from the EEPROM.
>> This is useful in situations where the EEPROM isn't properly programmed
>> or where the firmware wants to override the existing MAC address.
>>
>> Signed-off-by: Thierry Reding <treding@nvidia.com>
>> ---
>> Based on net-next.
>>
>> drivers/net/ethernet/realtek/r8169.c | 35 +++++++++++++++++-----------
>> 1 file changed, 22 insertions(+), 13 deletions(-)
>>
>> diff --git a/drivers/net/ethernet/realtek/r8169.c b/drivers/net/ethernet/realtek/r8169.c
>> index f574b6b557f9..fd9edd643ca5 100644
>> --- a/drivers/net/ethernet/realtek/r8169.c
>> +++ b/drivers/net/ethernet/realtek/r8169.c
>> @@ -6957,6 +6957,21 @@ static int rtl_alloc_irq(struct rtl8169_private *tp)
>> return pci_alloc_irq_vectors(tp->pci_dev, 1, 1, flags);
>> }
>>
>> +static void rtl_read_mac_address(struct rtl8169_private *tp,
>> + u8 mac_addr[ETH_ALEN])
>> +{
>> + /* Get MAC address */
>> + switch (tp->mac_version) {
>> + case RTL_GIGA_MAC_VER_35 ... RTL_GIGA_MAC_VER_38:
>> + case RTL_GIGA_MAC_VER_40 ... RTL_GIGA_MAC_VER_51:
>> + *(u32 *)&mac_addr[0] = rtl_eri_read(tp, 0xe0, ERIAR_EXGMAC);
>> + *(u16 *)&mac_addr[4] = rtl_eri_read(tp, 0xe4, ERIAR_EXGMAC);
>> + break;
>> + default:
>> + break;
>> + }
>> +}
>> +
>> DECLARE_RTL_COND(rtl_link_list_ready_cond)
>> {
>> return RTL_R8(tp, MCU) & LINK_LIST_RDY;
>> @@ -7148,6 +7163,7 @@ static int rtl_get_ether_clk(struct rtl8169_private *tp)
>> static int rtl_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
>> {
>> const struct rtl_cfg_info *cfg = rtl_cfg_infos + ent->driver_data;
>> + u8 mac_addr[ETH_ALEN] __aligned(4);
>
> Hi Thierry
>
> Maybe now would be a good time to cleanup this __aligned(4), pointer
> aliasing, etc?
>
Andrew, for my understanding: What do you think is wrong with the
alignment requirement? It was introduced because we do a 32 bit access
to the start address of the array and want to avoid an unaligned access.

>> + /* get MAC address */
>> + if (eth_platform_get_mac_address(&pdev->dev, mac_addr))
>> + rtl_read_mac_address(tp, mac_addr);
>> +
>
> Maybe that could be made more readable with:
>
> err = eth_platform_get_mac_address(&pdev->dev, mac_addr);
> if (err)
> rtl_read_mac_address(tp, mac_addr);
>
> Thanks
> Andrew
> .
>