[src/trunk]: src/sys/dev/pci msk(4): ack Status BMU IRQ only if we're (appare...

[jakllsch <jakllsch%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/ef6b393f57a9
branches:  trunk
changeset: 1010024:ef6b393f57a9
user:      jakllsch <jakllsch%NetBSD.org@localhost>
date:      Mon May 11 23:47:45 2020 +0000

description:
msk(4): ack Status BMU IRQ only if we're (apparently) caught up with it

Possibility for acking an unprocessed Status BMU IRQ still exists, and
remains handled by the watchdog.  Nevertheless this should reduce the
likelyhood that path is taken.

diffstat:

 sys/dev/pci/if_msk.c |  11 ++++++++---
 1 files changed, 8 insertions(+), 3 deletions(-)

diffs (47 lines):

diff -r d14db5d9a86c -r ef6b393f57a9 sys/dev/pci/if_msk.c
--- a/sys/dev/pci/if_msk.c      Mon May 11 21:51:25 2020 +0000
+++ b/sys/dev/pci/if_msk.c      Mon May 11 23:47:45 2020 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: if_msk.c,v 1.112 2020/05/11 19:17:46 jakllsch Exp $ */
+/* $NetBSD: if_msk.c,v 1.113 2020/05/11 23:47:45 jakllsch Exp $ */
 /*     $OpenBSD: if_msk.c,v 1.79 2009/10/15 17:54:56 deraadt Exp $     */
 
 /*
@@ -52,7 +52,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_msk.c,v 1.112 2020/05/11 19:17:46 jakllsch Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_msk.c,v 1.113 2020/05/11 23:47:45 jakllsch Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -2277,6 +2277,7 @@
        struct ifnet            *ifp0 = NULL, *ifp1 = NULL;
        uint32_t                status;
        struct msk_status_desc  *cur_st;
+       bool                    retried = false;
 
        status = CSR_READ_4(sc, SK_Y2_ISSR2);
        if (status == 0xffffffff)
@@ -2303,6 +2304,7 @@
                msk_intr_yukon(sc_if1);
        }
 
+again:
        MSK_CDSTSYNC(sc, sc->sk_status_idx,
            BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
        cur_st = &sc->sk_status_ring[sc->sk_status_idx];
@@ -2336,8 +2338,11 @@
                cur_st = &sc->sk_status_ring[sc->sk_status_idx];
        }
 
-       if (status & SK_Y2_IMR_BMU) {
+       if (CSR_READ_2(sc, SK_STAT_BMU_PUTIDX) == sc->sk_status_idx) {
                CSR_WRITE_4(sc, SK_STAT_BMU_CSR, SK_STAT_BMU_IRQ_CLEAR);
+       } else if (!retried) {
+               retried = true;
+               goto again;
        }
 
        CSR_WRITE_4(sc, SK_Y2_ICR, 2);