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authorriastradh <riastradh@NetBSD.org>2021-06-16 00:21:17 +0000
committerriastradh <riastradh@NetBSD.org>2021-06-16 00:21:17 +0000
commitbbdda93be2f0bfefe91466b398fe42700a6ea284 (patch)
treee75e77046575209dbb21f73d0bc44c61ec0ec6c0 /sys/dev/ic/bwfm.c
parent5a96957fa793651c8e7093a5a4c2fcae87232af2 (diff)
if_attach and if_initialize cannot fail, don't test return value
These were originally made failable back in 2017 when if_initialize allocated a softint in every interface for link state changes, so that it could fail gracefully instead of panicking: https://mail-index.NetBSD.org/source-changes/2017/10/23/msg089053.html However, this spawned many seldom- or never-tested error branches, which are risky to have around. And that softint in every interface has since been replaced by a single global workqueue, because link state changes require thread context but not low latency or high throughput: https://mail-index.NetBSD.org/source-changes/2020/02/06/msg113759.html So there is no longer any reason for if_initialize to fail. (The subroutine if_stats_init can't fail because percpu_alloc can't fail either.) There is a snag: the softint_establish in if_percpuq_create could fail, potentially leading to bad consequences later on trying to use the softint. This change doesn't introduce any new bugs because of the snag -- if_percpuq_attach was already broken. However, the snag can be better addressed without spawning error branches, either by using a single softint or making softints less scarce. (Separate commit will change the signatures of if_attach and if_initialize to return void, scheduled to ride whatever is the next convenient kernel bump.) Patch and testing on amd64 and evbmips64-eb by maya@; commit message soliloquy, and compile-testing on evbppc/i386/earmv7hf, by me.
Diffstat (limited to 'sys/dev/ic/bwfm.c')
-rw-r--r--sys/dev/ic/bwfm.c12
1 files changed, 2 insertions, 10 deletions
diff --git a/sys/dev/ic/bwfm.c b/sys/dev/ic/bwfm.c
index 89c1b08aefa..b42abf3004c 100644
--- a/sys/dev/ic/bwfm.c
+++ b/sys/dev/ic/bwfm.c
@@ -1,4 +1,4 @@
-/* $NetBSD: bwfm.c,v 1.30 2021/04/13 04:13:52 mrg Exp $ */
+/* $NetBSD: bwfm.c,v 1.31 2021/06/16 00:21:18 riastradh Exp $ */
/* $OpenBSD: bwfm.c,v 1.5 2017/10/16 22:27:16 patrick Exp $ */
/*
* Copyright (c) 2010-2016 Broadcom Corporation
@@ -422,15 +422,7 @@ bwfm_attach(struct bwfm_softc *sc)
IFQ_SET_READY(&ifp->if_snd);
memcpy(ifp->if_xname, DEVNAME(sc), IFNAMSIZ);
- error = if_initialize(ifp);
- if (error != 0) {
- printf("%s: if_initialize failed(%d)\n", DEVNAME(sc), error);
- pool_cache_destroy(sc->sc_freetask);
- workqueue_destroy(sc->sc_taskq);
-
- return; /* Error */
- }
-
+ if_initialize(ifp);
ieee80211_ifattach(ic);
sc->sc_newstate = ic->ic_newstate;
ic->ic_newstate = bwfm_newstate;