git: f5dc44c045c6 - main - ixgbe: Apply DMAC changes through an if-up reset request

The branch main has been updated by kbowling:

URL: https://cgit.FreeBSD.org/src/commit/?id=f5dc44c045c6f03a0f1bb2e81b0172e0781faec4

commit f5dc44c045c6f03a0f1bb2e81b0172e0781faec4
Author:     Kevin Bowling <kbowling@FreeBSD.org>
AuthorDate: 2026-09-11 21:48:43 +0000
Commit:     Kevin Bowling <kbowling@FreeBSD.org>
CommitDate: 2026-09-17 05:32:42 +0000

    ixgbe: Apply DMAC changes through an if-up reset request
    
    Serialize cached DMA coalescing policy with initialization and schedule
    its application through the admin task.  The old running check
    preceded if_init() acquiring the context lock, so an intervening down
    operation could be followed by an unconditional initialization.
    
    Use the deferred if-up request so restart permission is checked when the
    task runs.  Changes made while stopped or suspended remain cached for
    the next initialization.  Do not schedule a reset for an unchanged value.
    
    MFC after:      2 weeks
    Sponsored by:   BBOX.io
---
 sys/dev/ixgbe/if_ix.c | 23 +++++++++++++++--------
 1 file changed, 15 insertions(+), 8 deletions(-)

diff --git a/sys/dev/ixgbe/if_ix.c b/sys/dev/ixgbe/if_ix.c
index f5ceb1f0b5eb..2ece3b7bc433 100644
--- a/sys/dev/ixgbe/if_ix.c
+++ b/sys/dev/ixgbe/if_ix.c
@@ -5968,11 +5968,13 @@ static int
 ixgbe_sysctl_dmac(SYSCTL_HANDLER_ARGS)
 {
 	struct ixgbe_softc *sc = (struct ixgbe_softc *)arg1;
-	if_t ifp = iflib_get_ifp(sc->ctx);
+	struct sx *ctx_lock = iflib_ctx_lock_get(sc->ctx);
 	int error;
 	u16 newval;
 
+	sx_xlock(ctx_lock);
 	newval = sc->dmac;
+	sx_xunlock(ctx_lock);
 	error = sysctl_handle_16(oidp, &newval, 0, req);
 	if ((error) || (req->newptr == NULL))
 		return (error);
@@ -5980,11 +5982,10 @@ ixgbe_sysctl_dmac(SYSCTL_HANDLER_ARGS)
 	switch (newval) {
 	case 0:
 		/* Disabled */
-		sc->dmac = 0;
 		break;
 	case 1:
 		/* Enable and use default */
-		sc->dmac = 1000;
+		newval = 1000;
 		break;
 	case 50:
 	case 100:
@@ -5995,18 +5996,24 @@ ixgbe_sysctl_dmac(SYSCTL_HANDLER_ARGS)
 	case 5000:
 	case 10000:
 		/* Legal values - allow */
-		sc->dmac = newval;
 		break;
 	default:
 		/* Do nothing, illegal value */
 		return (EINVAL);
 	}
 
-	/* Re-initialize hardware if it's already running */
-	if (iflib_is_running(sc->ctx))
-		if_init(ifp, ifp);
+	sx_xlock(ctx_lock);
+	if (iflib_in_detach(sc->ctx)) {
+		error = ENXIO;
+	} else if (sc->dmac != newval) {
+		sc->dmac = newval;
+		/* Apply through init only if still administratively up. */
+		iflib_request_reset_if_up(sc->ctx);
+		iflib_admin_intr_deferred(sc->ctx);
+	}
+	sx_xunlock(ctx_lock);
 
-	return (0);
+	return (error);
 } /* ixgbe_sysctl_dmac */
 
 #ifdef IXGBE_DEBUG