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Commit deedf1fe authored by Thierry Reding's avatar Thierry Reding Committed by David S. Miller
Browse files

r8169: Avoid pointer aliasing 



Read MAC address 32-bit at a time and manually extract the individual
bytes. This avoids pointer aliasing and gives the compiler a better
chance of optimizing the operation.

Suggested-by: default avatarAndrew Lunn <andrew@lunn.ch>
Signed-off-by: default avatarThierry Reding <treding@nvidia.com>
Reviewed-by: default avatarAndrew Lunn <andrew@lunn.ch>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 04c7788c

drivers/net/ethernet/realtek/r8169.c

+13 −3
Original line number Diff line number Diff line
@@ -7113,12 +7113,21 @@ static int rtl_alloc_irq(struct rtl8169_private *tp) 
static void rtl_read_mac_address(struct rtl8169_private *tp,

				 u8 mac_addr[ETH_ALEN])

{

	u32 value;



	/* 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);

		value = rtl_eri_read(tp, 0xe0, ERIAR_EXGMAC);

		mac_addr[0] = (value >>  0) & 0xff;

		mac_addr[1] = (value >>  8) & 0xff;

		mac_addr[2] = (value >> 16) & 0xff;

		mac_addr[3] = (value >> 24) & 0xff;



		value = rtl_eri_read(tp, 0xe4, ERIAR_EXGMAC);

		mac_addr[4] = (value >>  0) & 0xff;

		mac_addr[5] = (value >>  8) & 0xff;

		break;

	default:

		break;
@@ -7316,7 +7325,8 @@ 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) = {};

	/* align to u16 for is_valid_ether_addr() */

	u8 mac_addr[ETH_ALEN] __aligned(2) = {};

	struct rtl8169_private *tp;

	struct net_device *dev;

	int chipset, region, i;