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Message-ID: <4FB1C6F8.7060902@lwfinger.net> (sfid-20120515_050129_368024_2B3DB1D3)
Date: Mon, 14 May 2012 22:01:12 -0500
From: Larry Finger <Larry.Finger@lwfinger.net>
MIME-Version: 1.0
To: Stanislav Yakovlev <stas.yakovlev@gmail.com>
CC: linville@tuxdriver.com, linux-wireless@vger.kernel.org
Subject: Re: [PATCH] net/wireless: ipw2100: Fix WARN_ON occurring in wiphy_register
 called by ipw2100_pci_init_one
References: <1337036779-16348-1-git-send-email-stas.yakovlev@gmail.com>
In-Reply-To: <1337036779-16348-1-git-send-email-stas.yakovlev@gmail.com>
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On 05/14/2012 06:06 PM, Stanislav Yakovlev wrote:
> The problem was found by Larry Finger:
> http://marc.info/?l=linux-wireless&m=133702401700614&w=2
>
> The problem is identical to the one for ipw2200 which is already fixed:
> http://marc.info/?l=linux-wireless&m=133457257407196&w=2
>
> [   17.766431] ------------[ cut here ]------------
> [   17.766467] WARNING: at net/wireless/core.c:562 wiphy_register+0x34c/0x3c0 [cfg80211]()
> [   17.766471] Hardware name: Latitude D600
> [   17.766474] Modules linked in: ipw2100(+) libipw pcmcia cfg80211 ppdev parport_pc yenta_socket sr_mod pcmcia_rsrc parport iTCO_wdt cdrom sg rfkill pcmcia_
> core lib80211 tg3 video button battery ac iTCO_vendor_support joydev shpchp pcspkr pciehp pci_hotplug autofs4 radeon ttm drm_kms_helper uhci_hcd ehci_hcd rtc
> _cmos thermal drm hwmon i2c_algo_bit i2c_core processor usbcore usb_common ata_generic ata_piix ahci libahci libata
> [   17.766525] Pid: 474, comm: modprobe Not tainted 3.4.0-rc7-wl+ #6
> [   17.766528] Call Trace:
> [   17.766541]  [<c066ad08>] ? printk+0x28/0x2a
> [   17.766552]  [<c0230edd>] warn_slowpath_common+0x6d/0xa0
> [   17.766563]  [<e0b253bc>] ? wiphy_register+0x34c/0x3c0 [cfg80211]
> [   17.766573]  [<e0b253bc>] ? wiphy_register+0x34c/0x3c0 [cfg80211]
> [   17.766578]  [<c0230f2d>] warn_slowpath_null+0x1d/0x20
> [   17.766588]  [<e0b253bc>] wiphy_register+0x34c/0x3c0 [cfg80211]
> [   17.766605]  [<e0b5b0d6>] ipw2100_wdev_init+0x196/0x1c0 [ipw2100]
> [   17.766616]  [<e0b5d962>] ipw2100_pci_init_one+0x2b2/0x694 [ipw2100]
> [   17.766632]  [<c047ce52>] local_pci_probe+0x42/0xb0
> [   17.766637]  [<c047e2b0>] pci_device_probe+0x60/0x90
> [   17.766645]  [<c0376de2>] ? sysfs_create_link+0x12/0x20
> [   17.766654]  [<c050f1f6>] really_probe+0x56/0x2e0
> [   17.766659]  [<c037636d>] ? create_dir+0x5d/0xa0
> [   17.766667]  [<c0518c6b>] ? pm_runtime_barrier+0x3b/0xa0
> [   17.766672]  [<c050f5e4>] driver_probe_device+0x44/0xa0
> [   17.766677]  [<c047e227>] ? pci_match_device+0x97/0xa0
> [   17.766681]  [<c050f6c9>] __driver_attach+0x89/0x90
> [   17.766686]  [<c050f640>] ? driver_probe_device+0xa0/0xa0
> [   17.766691]  [<c050da2a>] bus_for_each_dev+0x3a/0x70
> [   17.766695]  [<c050ee6c>] driver_attach+0x1c/0x30
> [   17.766699]  [<c050f640>] ? driver_probe_device+0xa0/0xa0
> [   17.766704]  [<c050ea77>] bus_add_driver+0x187/0x280
> [   17.766710]  [<c045b9cd>] ? kset_find_obj+0x2d/0x60
> [   17.766715]  [<c047e2e0>] ? pci_device_probe+0x90/0x90
> [   17.766719]  [<c047e2e0>] ? pci_device_probe+0x90/0x90
> [   17.766724]  [<c050fb85>] driver_register+0x65/0x110
> [   17.766729]  [<c047e09d>] __pci_register_driver+0x3d/0xa0
> [   17.766738]  [<e09f705c>] ipw2100_init+0x5c/0x1000 [ipw2100]
> [   17.766743]  [<c020110f>] do_one_initcall+0x2f/0x170
> [   17.766749]  [<e09f7000>] ? 0xe09f6fff
> [   17.766757]  [<c0287ce8>] sys_init_module+0xa8/0x210
> [   17.766766]  [<c067a075>] syscall_call+0x7/0xb
> [   17.766769] ---[ end trace 559898c6bb0d1c75 ]---
> [   17.767093] ipw2100: probe of 0000:02:03.0 failed with error -5
>
> This warning appears only if we apply Ben Hutchings' fix
> http://marc.info/?l=linux-wireless&m=132720204412667&w=2
> for the bug reported by Cesare Leonardi
> http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=656813
> with cfg80211 warning during device registration
> ("cfg80211: failed to add phy80211 symlink to netdev!").
>
> We separate device bring up and registration with network stack
> to avoid the problem.
>
> Signed-off-by: Stanislav Yakovlev<stas.yakovlev@gmail.com>
> ---
>
> Larry, can you test it once again?

Tested-by: Larry Finger <Larry.Finger@lwfinger.net>

Yes, this patch fixes the problem.

Larry