From mboxrd@z Thu Jan 1 00:00:00 1970 From: John W. Linville Date: Tue, 5 Jun 2012 14:24:10 -0400 Subject: [PATCH 1/1] b43: do not call ieee80211_unregister_hw if we are not registred In-Reply-To: <20120605164945.GB18176@thinkpad-t410> References: <1338536240-4392-1-git-send-email-bug-track@fisher-privat.net> <1338536240-4392-2-git-send-email-bug-track@fisher-privat.net> <20120605164945.GB18176@thinkpad-t410> Message-ID: <20120605182410.GA1937@tuxdriver.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Seth Forshee Cc: Oleksij Rempel , b43-dev@lists.infradead.org, Stefano Brivio , Larry Finger , linux-wireless@vger.kernel.org Could someone repost a clean version to linux-wireless at vger.kernel.org? On Tue, Jun 05, 2012 at 11:49:45AM -0500, Seth Forshee wrote: > (I don't have access to the original message, so I appologize if any > Cc's were dropped. I added some additional Cc's.) > > On Fri, Jun 01, 2012 at 09:37:20AM +0200, Oleksij Rempel wrote: > > this patch fixes kernel Oops on "rmmod b43" if firmware was not loaded: > > > > BUG: unable to handle kernel NULL pointer dereference at 0000000000000088 > > IP: [] drain_workqueue+0x25/0x142 > > PGD 153ac6067 PUD 153b82067 PMD 0 > > Oops: 0000 [#1] SMP > > > > Signed-off-by: Oleksij Rempel > > This issue is affecting the Ubuntu installer, and I've verified the > patch fixes the problem on a Mac Mini 5,2. > > Tested-by: Seth Forshee > > This issue affects 3.4, probably introduced in 6b6fa58 (b43: Load > firmware from a work queue and not from the probe routine), so I'd > suggest a Cc for stable also be added. > > > --- > > drivers/net/wireless/b43/b43.h | 4 ++++ > > drivers/net/wireless/b43/main.c | 19 ++++++++++++------- > > 2 files changed, 16 insertions(+), 7 deletions(-) > > > > diff --git a/drivers/net/wireless/b43/b43.h b/drivers/net/wireless/b43/b43.h > > index 67c13af..c06b6cb 100644 > > --- a/drivers/net/wireless/b43/b43.h > > +++ b/drivers/net/wireless/b43/b43.h > > @@ -877,6 +877,10 @@ struct b43_wl { > > * from the mac80211 subsystem. */ > > u16 mac80211_initially_registered_queues; > > > > + /* Set this if we call ieee80211_register_hw() and check if we call > > + * ieee80211_unregister_hw(). */ > > + bool hw_registred; > > + > > /* We can only have one operating interface (802.11 core) > > * at a time. General information about this interface follows. > > */ > > diff --git a/drivers/net/wireless/b43/main.c b/drivers/net/wireless/b43/main.c > > index e4d6dc2..747079b 100644 > > --- a/drivers/net/wireless/b43/main.c > > +++ b/drivers/net/wireless/b43/main.c > > @@ -2437,6 +2437,7 @@ start_ieee80211: > > err = ieee80211_register_hw(wl->hw); > > if (err) > > goto err_one_core_detach; > > + wl->hw_registred = true; > > b43_leds_register(wl->current_dev); > > goto out; > > > > @@ -5283,6 +5284,7 @@ static struct b43_wl *b43_wireless_init(struct b43_bus_dev *dev) > > > > hw->queues = modparam_qos ? B43_QOS_QUEUE_NUM : 1; > > wl->mac80211_initially_registered_queues = hw->queues; > > + wl->hw_registred = false; > > hw->max_rates = 2; > > SET_IEEE80211_DEV(hw, dev->dev); > > if (is_valid_ether_addr(sprom->et1mac)) > > @@ -5354,12 +5356,15 @@ static void b43_bcma_remove(struct bcma_device *core) > > * as the ieee80211 unreg will destroy the workqueue. */ > > cancel_work_sync(&wldev->restart_work); > > > > - /* Restore the queues count before unregistering, because firmware detect > > - * might have modified it. Restoring is important, so the networking > > - * stack can properly free resources. */ > > - wl->hw->queues = wl->mac80211_initially_registered_queues; > > - b43_leds_stop(wldev); > > - ieee80211_unregister_hw(wl->hw); > > + B43_WARN_ON(!wl); > > + if (wl->current_dev == wldev && wl->hw_registred) { > > + /* Restore the queues count before unregistering, because firmware detect > > + * might have modified it. Restoring is important, so the networking > > + * stack can properly free resources. */ > > + wl->hw->queues = wl->mac80211_initially_registered_queues; > > + b43_leds_stop(wldev); > > + ieee80211_unregister_hw(wl->hw); > > + } > > > > b43_one_core_detach(wldev->dev); > > > > @@ -5430,7 +5435,7 @@ static void b43_ssb_remove(struct ssb_device *sdev) > > cancel_work_sync(&wldev->restart_work); > > > > B43_WARN_ON(!wl); > > - if (wl->current_dev == wldev) { > > + if (wl->current_dev == wldev && wl->hw_registred) { > > /* Restore the queues count before unregistering, because firmware detect > > * might have modified it. Restoring is important, so the networking > > * stack can properly free resources. */ > > -- > > 1.7.9.5 > > > -- John W. Linville Someday the world will need a hero, and you linville at tuxdriver.com might be all we have. Be ready.