Subject: [PATCH 1/6] e1000e: Remove Other from EIAC

From: Benjamin Poirier <[email-masked]>
Date: Wed, 31 Jan 2018 16:26:27 +0900

commit 745d0bd3af99ccc8c5f5822f808cd133eadad6ac upstream.

It was reported that emulated e1000e devices in vmware esxi 6.5 Build
7526125 do not link up after commit 4aea7a5c5e94 ("e1000e: Avoid receiver
overrun interrupt bursts", v4.15-rc1). Some tracing shows that after
e1000e_trigger_lsc() is called, ICR reads out as 0x0 in e1000_msix_other()
on emulated e1000e devices. In comparison, on real e1000e 82574 hardware,
icr=0x80000004 (_INT_ASSERTED | _LSC) in the same situation.

Some experimentation showed that this flaw in vmware e1000e emulation can
be worked around by not setting Other in EIAC. This is how it was before
16ecba59bc33 ("e1000e: Do not read ICR in Other interrupt", v4.5-rc1).

Fixes: 4aea7a5c5e94 ("e1000e: Avoid receiver overrun interrupt bursts")
Signed-off-by: Benjamin Poirier <[email-masked]>
Tested-by: Aaron Brown <[email-masked]>
Signed-off-by: Jeff Kirsher <[email-masked]>
[bwh: Backported to 4.9: adjust context]
Cc: Yanhui He <[email-masked]>
Signed-off-by: Ben Hutchings <[email-masked]>
---
 drivers/net/ethernet/intel/e1000e/netdev.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index 9c95222e6536..46641e00ec0a 100644
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -1915,6 +1915,8 @@ static irqreturn_t e1000_msix_other(int __always_unused irq, void *data)
 	bool enable = true;
 
 	icr = er32(ICR);
+	ew32(ICR, E1000_ICR_OTHER);
+
 	if (icr & E1000_ICR_RXO) {
 		ew32(ICR, E1000_ICR_RXO);
 		enable = false;
@@ -2037,7 +2039,6 @@ static void e1000_configure_msix(struct e1000_adapter *adapter)
 		       hw->hw_addr + E1000_EITR_82574(vector));
 	else
 		writel(1, hw->hw_addr + E1000_EITR_82574(vector));
-	adapter->eiac_mask |= E1000_IMS_OTHER;
 
 	/* Cause Tx interrupts on every write back */
 	ivar |= BIT(31);
@@ -2262,7 +2263,7 @@ static void e1000_irq_enable(struct e1000_adapter *adapter)
 
 	if (adapter->msix_entries) {
 		ew32(EIAC_82574, adapter->eiac_mask & E1000_EIAC_MASK_82574);
-		ew32(IMS, adapter->eiac_mask | E1000_IMS_LSC);
+		ew32(IMS, adapter->eiac_mask | E1000_IMS_OTHER | E1000_IMS_LSC);
 	} else if ((hw->mac.type == e1000_pch_lpt) ||
 		   (hw->mac.type == e1000_pch_spt)) {
 		ew32(IMS, IMS_ENABLE_MASK | E1000_IMS_ECCER);