[PATCH 3/3] r8169: don't use MSI-X on RTL8106e

[Kai-Heng Feng]

From: Jian-Hong Pan <jian-hong at endlessm.com>

BugLink: https://bugs.launchpad.net/bugs/1779817

Found the ethernet network on ASUS X441UAR doesn't come back on resume
from suspend when using MSI-X.  The chip is RTL8106e - version 39.

[   21.848357] libphy: r8169: probed
[   21.848473] r8169 0000:02:00.0 eth0: RTL8106e, 0c:9d:92:32:67:b4, XID
44900000, IRQ 127
[   22.518860] r8169 0000:02:00.0 enp2s0: renamed from eth0
[   29.458041] Generic PHY r8169-200:00: attached PHY driver [Generic
PHY] (mii_bus:phy_addr=r8169-200:00, irq=IGNORE)
[   63.227398] r8169 0000:02:00.0 enp2s0: Link is Up - 100Mbps/Full -
flow control off
[  124.514648] Generic PHY r8169-200:00: attached PHY driver [Generic
PHY] (mii_bus:phy_addr=r8169-200:00, irq=IGNORE)

Here is the ethernet controller in detail:

02:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd.
RTL8101/2/6E PCI Express Fast/Gigabit Ethernet controller [10ec:8136]
(rev 07)
	Subsystem: ASUSTeK Computer Inc. RTL810xE PCI Express Fast
Ethernet controller [1043:200f]
	Flags: bus master, fast devsel, latency 0, IRQ 16
	I/O ports at e000 [size=256]
	Memory at ef100000 (64-bit, non-prefetchable) [size=4K]
	Memory at e0000000 (64-bit, prefetchable) [size=16K]
	Capabilities: <access denied>
	Kernel driver in use: r8169
	Kernel modules: r8169

Falling back to MSI fixes the issue.

Fixes: 6c6aa15fdea5 ("r8169: improve interrupt handling")
Signed-off-by: Jian-Hong Pan <jian-hong at endlessm.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
(backported from commit 7bb05b85bc2d1a1b647b91424b2ed4a18e6ecd81)
Signed-off-by: Kai-Heng Feng <kai.heng.feng at canonical.com>
---
 drivers/net/ethernet/realtek/r8169.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/realtek/r8169.c b/drivers/net/ethernet/realtek/r8169.c
index 9c6e65896108..64826f4f23bc 100644
--- a/drivers/net/ethernet/realtek/r8169.c
+++ b/drivers/net/ethernet/realtek/r8169.c
@@ -8300,17 +8300,20 @@ static int rtl_alloc_irq(struct rtl8169_private *tp)
 	void __iomem *ioaddr = tp->mmio_addr;
 	unsigned int flags;
 
-	if (tp->mac_version <= RTL_GIGA_MAC_VER_06) {
+	switch (tp->mac_version) {
+	case RTL_GIGA_MAC_VER_01 ... RTL_GIGA_MAC_VER_06:
 		RTL_W8(Cfg9346, Cfg9346_Unlock);
 		RTL_W8(Config2, RTL_R8(Config2) & ~MSIEnable);
 		RTL_W8(Cfg9346, Cfg9346_Lock);
 		flags = PCI_IRQ_LEGACY;
-	} else if (tp->mac_version == RTL_GIGA_MAC_VER_40) {
+		break;
+	case RTL_GIGA_MAC_VER_39 ... RTL_GIGA_MAC_VER_40:
 		/* This version was reported to have issues with resume
 		 * from suspend when using MSI-X
 		 */
 		flags = PCI_IRQ_LEGACY | PCI_IRQ_MSI;
-	} else {
+		break;
+	default:
 		flags = PCI_IRQ_ALL_TYPES;
 	}
 
-- 
2.17.1