git: 8838f3c32ac0 - main - rtwn: ensure TX work isn't scheduled during reset / abort

From: Adrian Chadd <adrian_at_FreeBSD.org>
Date: Fri, 08 Nov 2024 16:26:15 UTC
The branch main has been updated by adrian:

URL: https://cgit.FreeBSD.org/src/commit/?id=8838f3c32ac0ebcb8b20863f8c455375039a505e

commit 8838f3c32ac0ebcb8b20863f8c455375039a505e
Author:     Adrian Chadd <adrian@FreeBSD.org>
AuthorDate: 2024-11-08 16:26:05 +0000
Commit:     Adrian Chadd <adrian@FreeBSD.org>
CommitDate: 2024-11-08 16:26:05 +0000

    rtwn: ensure TX work isn't scheduled during reset / abort
    
    Don't schedule work during reset / abort.  For USB NICs, work
    must not be scheduled during a call to rtwn_usb_abort_xfers(),
    as then it'll cause the call to usbd_transfer_drain() to hang.
    
    This fixes a hang I've been seeing where the NIC hits a TX timeout
    and then the reset/re-init path is called.  If data is scheduled
    to be transmitted in that window, the call to usbd_transfer_drain()
    would hang and require a hard reboot to recover.
    
    Differential Revision: https://reviews.freebsd.org/D47479
---
 sys/dev/rtwn/if_rtwn_tx.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/sys/dev/rtwn/if_rtwn_tx.c b/sys/dev/rtwn/if_rtwn_tx.c
index f5e97933b314..bf45d14f7edc 100644
--- a/sys/dev/rtwn/if_rtwn_tx.c
+++ b/sys/dev/rtwn/if_rtwn_tx.c
@@ -263,6 +263,11 @@ rtwn_start(struct rtwn_softc *sc)
 	struct mbuf *m;
 
 	RTWN_ASSERT_LOCKED(sc);
+
+	/* Ensure no work is scheduled during reset/teardown */
+	if ((sc->sc_flags & RTWN_RUNNING) == 0)
+		return;
+
 	while ((m = mbufq_dequeue(&sc->sc_snd)) != NULL) {
 		if (sc->qfullmsk != 0) {
 			mbufq_prepend(&sc->sc_snd, m);