[PATCH net] r8169: don't use MSI-X on RTL8168g

[PATCH net] r8169: don't use MSI-X on RTL8168g

[Heiner Kallweit]

There have been two reports that network doesn't come back on resume
from suspend when using MSI-X. Both cases affect the same chip version
(RTL8168g - version 40), on different systems. Falling back to MSI
fixes the issue.
Even though we don't really have a proof yet that the network chip
version is to blame, let's disable MSI-X for this version.

Reported-by: Steve Dodd <steved424@gmail.com>
Reported-by: Lou Reed <gogen@disroot.org>
Tested-by: Steve Dodd <steved424@gmail.com>
Tested-by: Lou Reed <gogen@disroot.org>
Fixes: 6c6aa15fdea5 ("r8169: improve interrupt handling")
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
---
 drivers/net/ethernet/realtek/r8169.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/net/ethernet/realtek/r8169.c b/drivers/net/ethernet/realtek/r8169.c
index 344d77d9..d103e4dd 100644
--- a/drivers/net/ethernet/realtek/r8169.c
+++ b/drivers/net/ethernet/realtek/r8169.c
@@ -7076,6 +7076,11 @@ static int rtl_alloc_irq(struct rtl8169_private *tp)
 		RTL_W8(tp, Config2, RTL_R8(tp, Config2) & ~MSIEnable);
 		RTL_W8(tp, Cfg9346, Cfg9346_Lock);
 		flags = PCI_IRQ_LEGACY;
+	} else if (tp->mac_version == 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 {
 		flags = PCI_IRQ_ALL_TYPES;
 	}
-- 
2.18.0

Re: [PATCH net] r8169: don't use MSI-X on RTL8168g

[David Miller]

From: Heiner Kallweit <hkallweit1@gmail.com>
Date: Sun, 12 Aug 2018 13:26:26 +0200

> There have been two reports that network doesn't come back on resume
> from suspend when using MSI-X. Both cases affect the same chip version
> (RTL8168g - version 40), on different systems. Falling back to MSI
> fixes the issue.
> Even though we don't really have a proof yet that the network chip
> version is to blame, let's disable MSI-X for this version.
> 
> Reported-by: Steve Dodd <steved424@gmail.com>
> Reported-by: Lou Reed <gogen@disroot.org>
> Tested-by: Steve Dodd <steved424@gmail.com>
> Tested-by: Lou Reed <gogen@disroot.org>
> Fixes: 6c6aa15fdea5 ("r8169: improve interrupt handling")
> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>

Applied and queued up for -stable.