From fd0206ff357f54b4e732c8247188a42e5346aa3c Mon Sep 17 00:00:00 2001
From: martin <martin@NetBSD.org>
Date: Wed, 20 Jul 2022 18:48:41 +0000
Subject: [PATCH] When we init the hardware's rx/tx ring configuration we need
 to adjust our internal state, as this implicitly resets the current
 descriptor pointer. Previously "ifconfig eqos0 down; ifconfig eqos0 up" made
 the interface non-functional.

---
 sys/dev/ic/dwc_eqos.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/sys/dev/ic/dwc_eqos.c b/sys/dev/ic/dwc_eqos.c
index c28a7a826d75..609cd8144147 100644
--- a/sys/dev/ic/dwc_eqos.c
+++ b/sys/dev/ic/dwc_eqos.c
@@ -1,4 +1,4 @@
-/* $NetBSD: dwc_eqos.c,v 1.6 2022/04/16 23:20:47 jmcneill Exp $ */
+/* $NetBSD: dwc_eqos.c,v 1.7 2022/07/20 18:48:41 martin Exp $ */
 
 /*-
  * Copyright (c) 2022 Jared McNeill <jmcneill@invisible.ca>
@@ -33,7 +33,7 @@
 #include "opt_net_mpsafe.h"
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: dwc_eqos.c,v 1.6 2022/04/16 23:20:47 jmcneill Exp $");
+__KERNEL_RCSID(0, "$NetBSD: dwc_eqos.c,v 1.7 2022/07/20 18:48:41 martin Exp $");
 
 #include <sys/param.h>
 #include <sys/bus.h>
@@ -510,7 +510,13 @@ eqos_reset(struct eqos_softc *sc)
 static void
 eqos_init_rings(struct eqos_softc *sc, int qid)
 {
-	sc->sc_tx.queued = 0;
+	/*
+	 * We reset the rings paddr, this implicitly resets
+	 * the hardwares current descriptor pointer.
+	 * Adjust our internal state accordingly.
+	 */
+	sc->sc_tx.cur = sc->sc_tx.next = sc->sc_tx.queued = 0;
+	sc->sc_rx.cur = sc->sc_rx.next = sc->sc_rx.queued = 0;
 
 	WR4(sc, GMAC_DMA_CHAN0_TX_BASE_ADDR_HI,
 	    (uint32_t)(sc->sc_tx.desc_ring_paddr >> 32));