git: 594a25fa4304 - stable/13 - e1000: Re-arm link changes

[Kevin Bowling]

The branch stable/13 has been updated by kbowling (ports committer):

URL: https://cgit.FreeBSD.org/src/commit/?id=594a25fa43049c336d6016002538cad7a5383284

commit 594a25fa43049c336d6016002538cad7a5383284
Author:     Kevin Bowling <kbowling at FreeBSD.org>
AuthorDate: 2021-09-27 16:17:48 +0000
Commit:     Kevin Bowling <kbowling at FreeBSD.org>
CommitDate: 2021-09-28 16:55:59 +0000

    e1000: Re-arm link changes
    
    A change to MSI-X link handler was somehow causing issues on
    MSI-based em(4) NICs.
    
    Revert the change based on user reports and testing.
    
    PR:             258551
    Reported by:    Franco Fichtner <franco at opnsense.org>, t_uemura at macome.co.jp
    Reviewed by:    markj, Franco Fichtner <franco at opnsense.org>
    Tested by:      t_uemura at macome.co.jp
    MFC after:      1 day
    
    (cherry picked from commit 450c3f8b3d259c7eb82488319aff45f1f6554aaf)
---
 sys/dev/e1000/if_em.c | 22 ++++++----------------
 1 file changed, 6 insertions(+), 16 deletions(-)

diff --git a/sys/dev/e1000/if_em.c b/sys/dev/e1000/if_em.c
index 47513c5d9e1e..34d7b8f5f87e 100644
--- a/sys/dev/e1000/if_em.c
+++ b/sys/dev/e1000/if_em.c
@@ -1495,7 +1495,6 @@ em_msix_link(void *arg)
 {
 	struct e1000_softc *sc = arg;
 	u32 reg_icr;
-	bool notlink = false;
 
 	++sc->link_irq;
 	MPASS(sc->hw.back != NULL);
@@ -1506,17 +1505,14 @@ em_msix_link(void *arg)
 
 	if (reg_icr & (E1000_ICR_RXSEQ | E1000_ICR_LSC))
 		em_handle_link(sc->ctx);
-	else
-		notlink = true;
 
-	/* Re-arm for other/spurious interrupts */
-	if (notlink && sc->hw.mac.type >= igb_mac_min) {
+	/* Re-arm unconditionally */
+	if (sc->hw.mac.type >= igb_mac_min) {
 		E1000_WRITE_REG(&sc->hw, E1000_IMS, E1000_IMS_LSC);
 		E1000_WRITE_REG(&sc->hw, E1000_EIMS, sc->link_mask);
 	} else if (sc->hw.mac.type == e1000_82574) {
-		if (notlink)
-			E1000_WRITE_REG(&sc->hw, E1000_IMS, E1000_IMS_LSC |
-			    E1000_IMS_OTHER);
+		E1000_WRITE_REG(&sc->hw, E1000_IMS, E1000_IMS_LSC |
+		    E1000_IMS_OTHER);
 		/*
 		 * Because we must read the ICR for this interrupt it may
 		 * clear other causes using autoclear, for this reason we
@@ -1524,7 +1520,8 @@ em_msix_link(void *arg)
 		 */
 		if (reg_icr)
 			E1000_WRITE_REG(&sc->hw, E1000_ICS, sc->ims);
-	}
+	} else
+		E1000_WRITE_REG(&sc->hw, E1000_IMS, E1000_IMS_LSC);
 
 	return (FILTER_HANDLED);
 }
@@ -1873,13 +1870,6 @@ em_if_update_admin_status(if_ctx_t ctx)
 
 	if (hw->mac.type < em_mac_min)
 		lem_smartspeed(sc);
-	else if (hw->mac.type >= igb_mac_min &&
-	    sc->intr_type == IFLIB_INTR_MSIX) {
-		E1000_WRITE_REG(&sc->hw, E1000_IMS, E1000_IMS_LSC);
-		E1000_WRITE_REG(&sc->hw, E1000_EIMS, sc->link_mask);
-	} else if (hw->mac.type == e1000_82574 &&
-	    sc->intr_type == IFLIB_INTR_MSIX)
-		E1000_WRITE_REG(hw, E1000_IMS, E1000_IMS_LSC | E1000_IMS_OTHER);
 }
 
 static void