MFC r301309

sfxge(4): always be ready to receive batched events

When the low-latency firmware variant is running, it is reported as not
being capable of batching RX events, but it can still do so if the
FORCE_EV_MERGING flag is set on an RXQ.  Therefore we need to handle
batched RX events even if the capability isn't set.

If this bug is fixed in the firmware such that the capability is set
even when running the low-latency firmware variant, it will almost
always be reported so I don't think we lose much by removing the check.

Submitted by:   Mark Spender <mspender at solarflare.com>
Sponsored by:   Solarflare Communications, Inc.
Differential Revision:  https://reviews.freebsd.org/D6705

2 files changed, 6 insertions, 4 deletions

diff --git a/sys/dev/sfxge/common/ef10_nic.c b/sys/dev/sfxge/common/ef10_nic.c
index c607f2d..6d04bcd 100644
--- a/sys/dev/sfxge/common/ef10_nic.c
+++ b/sys/dev/sfxge/common/ef10_nic.c
@@ -1003,8 +1003,11 @@ ef10_get_datapath_caps(
 	encp->enc_rx_batching_enabled =
 	    CAP_FLAG(flags, RX_BATCHING) ? B_TRUE : B_FALSE;
 
-	if (encp->enc_rx_batching_enabled)
-		encp->enc_rx_batch_max = 16;
+	/*
+	 * Even if batching isn't reported as supported, we may still get
+	 * batched events.
+	 */
+	encp->enc_rx_batch_max = 16;
 
 	/* Check if the firmware supports disabling scatter on RXQs */
 	encp->enc_rx_disable_scatter_supported =
diff --git a/sys/dev/sfxge/sfxge_ev.c b/sys/dev/sfxge/sfxge_ev.c
index cfa106a..d5aff5f 100644
--- a/sys/dev/sfxge/sfxge_ev.c
+++ b/sys/dev/sfxge/sfxge_ev.c
@@ -123,8 +123,7 @@ sfxge_ev_rx(void *arg, uint32_t label, uint32_t id, uint32_t size,
 	rxq->pending += delta;
 
 	if (delta != 1) {
-		if ((!efx_nic_cfg_get(sc->enp)->enc_rx_batching_enabled) ||
-		    (delta <= 0) ||
+		if ((delta <= 0) ||
 		    (delta > efx_nic_cfg_get(sc->enp)->enc_rx_batch_max)) {
 			evq->exception = B_TRUE;