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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/dwc_gmac.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These were originally made failable back in 2017 when if_initialize allocated a softint in every interface for link state changes, so that it could fail gracefully instead of panicking: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 And that softint in every interface has since been replaced by a single global workqueue, because link state changes require thread context but not low latency or high throughput: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/dwc_gmac.c')
-rw-r--r--sys/dev/ic/dwc_gmac.c15
1 files changed, 3 insertions, 12 deletions
diff --git a/sys/dev/ic/dwc_gmac.c b/sys/dev/ic/dwc_gmac.c
index e12d86a8ffa..1d2a7fa50a0 100644
--- a/sys/dev/ic/dwc_gmac.c
+++ b/sys/dev/ic/dwc_gmac.c
@@ -1,4 +1,4 @@
-/* $NetBSD: dwc_gmac.c,v 1.73 2021/05/13 05:56:39 msaitoh Exp $ */
+/* $NetBSD: dwc_gmac.c,v 1.74 2021/06/16 00:21:18 riastradh Exp $ */
/*-
* Copyright (c) 2013, 2014 The NetBSD Foundation, Inc.
@@ -41,7 +41,7 @@
#include <sys/cdefs.h>
-__KERNEL_RCSID(1, "$NetBSD: dwc_gmac.c,v 1.73 2021/05/13 05:56:39 msaitoh Exp $");
+__KERNEL_RCSID(1, "$NetBSD: dwc_gmac.c,v 1.74 2021/06/16 00:21:18 riastradh Exp $");
/* #define DWC_GMAC_DEBUG 1 */
@@ -188,7 +188,6 @@ dwc_gmac_attach(struct dwc_gmac_softc *sc, int phy_id, uint32_t mii_clk)
struct mii_data * const mii = &sc->sc_mii;
struct ifnet * const ifp = &sc->sc_ec.ec_if;
prop_dictionary_t dict;
- int rv;
mutex_init(&sc->sc_mdio_lock, MUTEX_DEFAULT, IPL_NET);
sc->sc_mii_clk = mii_clk & 7;
@@ -332,9 +331,7 @@ dwc_gmac_attach(struct dwc_gmac_softc *sc, int phy_id, uint32_t mii_clk)
* Ready, attach interface
*/
/* Attach the interface. */
- rv = if_initialize(ifp);
- if (rv != 0)
- goto fail_2;
+ if_initialize(ifp);
sc->sc_ipq = if_percpuq_create(&sc->sc_ec.ec_if);
if_deferred_start_init(ifp, NULL);
ether_ifattach(ifp, enaddr);
@@ -355,12 +352,6 @@ dwc_gmac_attach(struct dwc_gmac_softc *sc, int phy_id, uint32_t mii_clk)
return 0;
-fail_2:
- ifmedia_removeall(&mii->mii_media);
- mii_detach(mii, MII_PHY_ANY, MII_OFFSET_ANY);
- mutex_destroy(&sc->sc_txq.t_mtx);
- mutex_destroy(&sc->sc_rxq.r_mtx);
- mutex_obj_free(sc->sc_lock);
fail:
dwc_gmac_free_rx_ring(sc, &sc->sc_rxq);
dwc_gmac_free_tx_ring(sc, &sc->sc_txq);