Introduce a tunable that disables use of MSI.

Non-zero value will use INTx.

2 files changed, 10 insertions, 0 deletions

diff --git a/sys/dev/bge/if_bge.c b/sys/dev/bge/if_bge.c
index ea477fd..bb4c7a7 100644
--- a/sys/dev/bge/if_bge.c
+++ b/sys/dev/bge/if_bge.c
@@ -2745,6 +2745,9 @@ bge_can_use_msi(struct bge_softc *sc)
 {
 	int can_use_msi = 0;
 
+	if (sc->bge_msi_disable != 0)
+		return (0);
+
 	/* Disable MSI for polling(4). */
 #ifdef DEVICE_POLLING
 	return (0);
@@ -5627,6 +5630,12 @@ bge_add_sysctls(struct bge_softc *sc)
 	    "Number of fragmented TX buffers of a frame allowed before "
 	    "forced collapsing");
 
+	sc->bge_msi_disable = 0;
+	snprintf(tn, sizeof(tn), "dev.bge.%d.msi_disable", unit);
+	TUNABLE_INT_FETCH(tn, &sc->bge_msi_disable);
+	SYSCTL_ADD_INT(ctx, children, OID_AUTO, "msi_disable",
+	    CTLFLAG_RD, &sc->bge_msi_disable, 0, "Disable MSI");
+
 	/*
 	 * It seems all Broadcom controllers have a bug that can generate UDP
 	 * datagrams with checksum value 0 when TX UDP checksum offloading is
diff --git a/sys/dev/bge/if_bgereg.h b/sys/dev/bge/if_bgereg.h
index ccb2c6d..de06b2b 100644
--- a/sys/dev/bge/if_bgereg.h
+++ b/sys/dev/bge/if_bgereg.h
@@ -2864,6 +2864,7 @@ struct bge_softc {
 	int			bge_timer;
 	int			bge_forced_collapse;
 	int			bge_forced_udpcsum;
+	int			bge_msi_disable;
 	int			bge_csum_features;
 	struct callout		bge_stat_ch;
 	uint32_t		bge_rx_discards;