[PATCH] net: e1000: do not attempt to set hwaddr for i210 without FLASH

[Tim Harvey]

commit f1bcad22dd19 ("net: e1000: add support for writing to EEPROM")
adds support for storing hwaddr in EEPROM however i210 devices do not
support this and thus results in errors such as:
Warning: e1000#0 failed to set MAC address'

Check if a flash device is present and if not return -ENOSYS indicating
this is not supported.

Signed-off-by: Tim Harvey <tharvey at gateworks.com>
---
 drivers/net/e1000.c | 4 ++++
 drivers/net/e1000.h | 1 +
 2 files changed, 5 insertions(+)

diff --git a/drivers/net/e1000.c b/drivers/net/e1000.c
index 694114eca7..60613b7df0 100644
--- a/drivers/net/e1000.c
+++ b/drivers/net/e1000.c
@@ -5673,6 +5673,10 @@ static int e1000_write_hwaddr(struct eth_device *dev)
 
 	DEBUGOUT("%s: mac=%pM\n", __func__, mac);
 
+	if ((hw->eeprom.type == e1000_eeprom_invm) &&
+	    !(E1000_READ_REG(hw, EECD) & E1000_EECD_FLASH_DETECTED_I210))
+		return -ENOSYS;
+
 	memset(current_mac, 0, 6);
 
 	/* Read from EEPROM, not from registers, to make sure
diff --git a/drivers/net/e1000.h b/drivers/net/e1000.h
index 072851ba31..082154a997 100644
--- a/drivers/net/e1000.h
+++ b/drivers/net/e1000.h
@@ -1245,6 +1245,7 @@ struct e1000_hw {
 #define E1000_EECD_FLUPD     0x00080000 /* Update FLASH */
 #define E1000_EECD_FLUPD_I210       0x00800000 /* Update FLASH */
 #define E1000_EECD_FLUDONE_I210     0x04000000 /* Update FLASH done*/
+#define E1000_EECD_FLASH_DETECTED_I210	0x00080000 /* FLASH detected */
 #define E1000_FLUDONE_ATTEMPTS      20000
 #define E1000_EECD_AUPDEN    0x00100000 /* Enable Autonomous FLASH update */
 #define E1000_EECD_SHADV     0x00200000 /* Shadow RAM Data Valid */
-- 
2.17.1