e1000e: fix legacy interrupt handling in i219

This fix handles a hardware issue that prevented i219 from
working in legacy interrupts mode (IntMode=0)
Signed-off-by: Yanir Lubetkin <yanirx.lubetkin@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/e1000e/ich8lan.h

@@ -98,8 +98,11 @@
 #define E1000_FEXTNVM6_K1_OFF_ENABLE	0x80000000
 /* bit for disabling packet buffer read */
 #define E1000_FEXTNVM7_DISABLE_PB_READ	0x00040000
-
+#define E1000_FEXTNVM7_SIDE_CLK_UNGATE	0x00000004
 #define E1000_FEXTNVM7_DISABLE_SMB_PERST	0x00000020
+#define E1000_FEXTNVM9_IOSFSB_CLKGATE_DIS	0x00000800
+#define E1000_FEXTNVM9_IOSFSB_CLKREQ_DIS	0x00001000
+#define E1000_FEXTNVM11_DISABLE_PB_READ		0x00000200
 #define E1000_FEXTNVM11_DISABLE_MULR_FIX	0x00002000
 
 /* bit24: RXDCTL thresholds granularity: 0 - cache lines, 1 - descriptors */

drivers/net/ethernet/intel/e1000e/netdev.c

@@ -4120,6 +4120,20 @@ void e1000e_reset(struct e1000_adapter *adapter)
 		phy_data &= ~IGP02E1000_PM_SPD;
 		e1e_wphy(hw, IGP02E1000_PHY_POWER_MGMT, phy_data);
 	}
+	if (hw->mac.type == e1000_pch_spt && adapter->int_mode == 0) {
+		u32 reg;
+
+		/* Fextnvm7 @ 0xe4[2] = 1 */
+		reg = er32(FEXTNVM7);
+		reg |= E1000_FEXTNVM7_SIDE_CLK_UNGATE;
+		ew32(FEXTNVM7, reg);
+		/* Fextnvm9 @ 0x5bb4[13:12] = 11 */
+		reg = er32(FEXTNVM9);
+		reg |= E1000_FEXTNVM9_IOSFSB_CLKGATE_DIS |
+		       E1000_FEXTNVM9_IOSFSB_CLKREQ_DIS;
+		ew32(FEXTNVM9, reg);
+	}
+
 }
 
 int e1000e_up(struct e1000_adapter *adapter)

drivers/net/ethernet/intel/e1000e/regs.h

@@ -38,6 +38,7 @@
 #define E1000_FEXTNVM4	0x00024	/* Future Extended NVM 4 - RW */
 #define E1000_FEXTNVM6	0x00010	/* Future Extended NVM 6 - RW */
 #define E1000_FEXTNVM7	0x000E4	/* Future Extended NVM 7 - RW */
+#define E1000_FEXTNVM9	0x5BB4  /* Future Extended NVM 9 - RW */
 #define E1000_FEXTNVM11	0x5BBC  /* Future Extended NVM 11 - RW */
 #define E1000_PCIEANACFG	0x00F18	/* PCIE Analog Config */
 #define E1000_FCT	0x00030	/* Flow Control Type - RW */