(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: [<ffffffff8104e988>] drain_workqueue+0x25/0x142
> PGD 153ac6067 PUD 153b82067 PMD 0
> Oops: 0000 [#1] SMP
>
> Signed-off-by: Oleksij Rempel
> <bug-track-m18mab7tlt0ycq4ww13eyl6hyfs7n...@public.gmane.org>
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 <seth.fors...@canonical.com>
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
>
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