Hi,
As pointed out by git-bisect, commit ecb44335 (mac80211: fix
suspend/resume races with unregister hw) broke booting on my ThinkPad
R50e. Looks like the rtnl_lock() around rdev->wiphy.registered = true
leads to a deadlock, possibly because ipw2200 is built-in in my
config. Testing with the additional debug patch
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -616,9 +616,8 @@ int wiphy_register(struct wiphy *wiphy)
if (res)
goto out_rm_dev;
- rtnl_lock();
+ WARN_ON(rtnl_is_locked());
rdev->wiphy.registered = true;
- rtnl_unlock();
return 0;
on top of c455ea4f (rc6+) leads to a working system with
[ 1.020738] ipw2200: Intel(R) PRO/Wireless 2200/2915 Network Driver, 1.2.2kmpr
[ 1.020812] ipw2200: Copyright(c) 2003-2006 Intel Corporation
[ 1.023406] ACPI: PCI Interrupt Link [LNKF] enabled at IRQ 11
[ 1.025717] ipw2200 0000:02:02.0: PCI INT A -> Link[LNKF] -> GSI 11 (level, low
) -> IRQ 11
[ 1.028048] ipw2200: Detected Intel PRO/Wireless 2200BG Network Connection
[ 1.148058] ------------[ cut here ]------------
[ 1.150393] WARNING: at net/wireless/core.c:619 wiphy_register+0x4c1/0x58c()
[ 1.152781] Hardware name: 1834S5G
[ 1.155126] Pid: 1, comm: swapper Not tainted 3.1.0-rc6+ #86
[ 1.157520] Call Trace:
[ 1.159871] [<c1028b98>] warn_slowpath_common+0x69/0x90
[ 1.162241] [<c13ee7a8>] ? wiphy_register+0x4c1/0x58c
[ 1.164617] [<c13ee7a8>] ? wiphy_register+0x4c1/0x58c
[ 1.166924] [<c1028be1>] warn_slowpath_null+0x22/0x24
[ 1.169230] [<c13ee7a8>] wiphy_register+0x4c1/0x58c
[ 1.171564] [<c12daad0>] ? ipw_net_init+0x1e6/0x2d0
[ 1.173890] [<c12da995>] ipw_net_init+0xab/0x2d0
[ 1.176173] [<c1375032>] register_netdevice+0x70/0x271
[ 1.178446] [<c137524e>] register_netdev+0x1b/0x28
[ 1.180688] [<c142f5b8>] ipw_pci_probe+0x7c3/0x891
[ 1.182892] [<c11a6f93>] local_pci_probe+0x40/0x9a
[ 1.185086] [<c11a7c98>] pci_device_probe+0x56/0x71
[ 1.187259] [<c128c902>] driver_probe_device+0x6c/0x177
[ 1.189453] [<c11a6ed9>] ? pci_match_device+0x80/0x85
[ 1.191615] [<c128ca79>] __driver_attach+0x6c/0x6e
[ 1.193794] [<c128c257>] bus_for_each_dev+0x4a/0x68
[ 1.195936] [<c128c7b4>] driver_attach+0x1e/0x20
[ 1.198043] [<c128ca0d>] ? driver_probe_device+0x177/0x177
[ 1.200151] [<c128bce5>] bus_add_driver+0x186/0x231
[ 1.202247] [<c11a7b3c>] ? pci_dev_put+0x16/0x16
[ 1.204320] [<c128cfac>] driver_register+0x6a/0x118
[ 1.206386] [<c120665f>] ? misc_register+0xc2/0x133
[ 1.208425] [<c15ee31e>] ? parse_early_options+0x25/0x25
[ 1.210423] [<c11a7e66>] __pci_register_driver+0x33/0x8c
[ 1.212393] [<c15ee31e>] ? parse_early_options+0x25/0x25
[ 1.214384] [<c160e0e8>] ipw_init+0x30/0x75
[ 1.216356] [<c15ee24c>] do_one_initcall+0x86/0x133
[ 1.218340] [<c160e0b8>] ? tun_init+0x8b/0x8b
[ 1.220315] [<c15ee31e>] ? parse_early_options+0x25/0x25
[ 1.222270] [<c15ee393>] kernel_init+0x75/0x10c
[ 1.224214] [<c14349b6>] kernel_thread_helper+0x6/0x10
[ 1.226124] ---[ end trace 4ef665623022622c ]---
[ 1.228121] ipw2200: Detected geography ZZR (14 802.11bg channels, 0 802.11a channels)
in dmesg. It's a shoot in the dark, but register_netdev() issues
rtnl_lock() before calling register_netdevice(), so wiphy_register()
can't possibly acquire the rtnl mutex in the same call chain, or can
it?
--
Thanks,
Feri.
On Sat, Sep 17, 2011 at 6:23 AM, Ferenc Wagner <[email protected]> wrote:
> Hi,
>
> As pointed out by git-bisect, commit ecb44335 (mac80211: fix
> suspend/resume races with unregister hw) broke booting on my ThinkPad
> R50e. Looks like the rtnl_lock() around rdev->wiphy.registered = true
> leads to a deadlock, possibly because ipw2200 is built-in in my
> config. ?Testing with the additional debug patch
>
> --- a/net/wireless/core.c
> +++ b/net/wireless/core.c
> @@ -616,9 +616,8 @@ int wiphy_register(struct wiphy *wiphy)
> ? ? ? ?if (res)
> ? ? ? ? ? ? ? ?goto out_rm_dev;
>
> - ? ? ? rtnl_lock();
> + ? ? ? WARN_ON(rtnl_is_locked());
> ? ? ? ?rdev->wiphy.registered = true;
> - ? ? ? rtnl_unlock();
> ? ? ? ?return 0;
>
> on top of c455ea4f (rc6+) leads to a working system with
>
> [ ? ?1.020738] ipw2200: Intel(R) PRO/Wireless 2200/2915 Network Driver, 1.2.2kmpr
> [ ? ?1.020812] ipw2200: Copyright(c) 2003-2006 Intel Corporation
> [ ? ?1.023406] ACPI: PCI Interrupt Link [LNKF] enabled at IRQ 11
> [ ? ?1.025717] ipw2200 0000:02:02.0: PCI INT A -> Link[LNKF] -> GSI 11 (level, low
> ) -> IRQ 11
> [ ? ?1.028048] ipw2200: Detected Intel PRO/Wireless 2200BG Network Connection
> [ ? ?1.148058] ------------[ cut here ]------------
> [ ? ?1.150393] WARNING: at net/wireless/core.c:619 wiphy_register+0x4c1/0x58c()
> [ ? ?1.152781] Hardware name: 1834S5G
> [ ? ?1.155126] Pid: 1, comm: swapper Not tainted 3.1.0-rc6+ #86
> [ ? ?1.157520] Call Trace:
> [ ? ?1.159871] ?[<c1028b98>] warn_slowpath_common+0x69/0x90
> [ ? ?1.162241] ?[<c13ee7a8>] ? wiphy_register+0x4c1/0x58c
> [ ? ?1.164617] ?[<c13ee7a8>] ? wiphy_register+0x4c1/0x58c
> [ ? ?1.166924] ?[<c1028be1>] warn_slowpath_null+0x22/0x24
> [ ? ?1.169230] ?[<c13ee7a8>] wiphy_register+0x4c1/0x58c
> [ ? ?1.171564] ?[<c12daad0>] ? ipw_net_init+0x1e6/0x2d0
> [ ? ?1.173890] ?[<c12da995>] ipw_net_init+0xab/0x2d0
> [ ? ?1.176173] ?[<c1375032>] register_netdevice+0x70/0x271
> [ ? ?1.178446] ?[<c137524e>] register_netdev+0x1b/0x28
> [ ? ?1.180688] ?[<c142f5b8>] ipw_pci_probe+0x7c3/0x891
> [ ? ?1.182892] ?[<c11a6f93>] local_pci_probe+0x40/0x9a
> [ ? ?1.185086] ?[<c11a7c98>] pci_device_probe+0x56/0x71
> [ ? ?1.187259] ?[<c128c902>] driver_probe_device+0x6c/0x177
> [ ? ?1.189453] ?[<c11a6ed9>] ? pci_match_device+0x80/0x85
> [ ? ?1.191615] ?[<c128ca79>] __driver_attach+0x6c/0x6e
> [ ? ?1.193794] ?[<c128c257>] bus_for_each_dev+0x4a/0x68
> [ ? ?1.195936] ?[<c128c7b4>] driver_attach+0x1e/0x20
> [ ? ?1.198043] ?[<c128ca0d>] ? driver_probe_device+0x177/0x177
> [ ? ?1.200151] ?[<c128bce5>] bus_add_driver+0x186/0x231
> [ ? ?1.202247] ?[<c11a7b3c>] ? pci_dev_put+0x16/0x16
> [ ? ?1.204320] ?[<c128cfac>] driver_register+0x6a/0x118
> [ ? ?1.206386] ?[<c120665f>] ? misc_register+0xc2/0x133
> [ ? ?1.208425] ?[<c15ee31e>] ? parse_early_options+0x25/0x25
> [ ? ?1.210423] ?[<c11a7e66>] __pci_register_driver+0x33/0x8c
> [ ? ?1.212393] ?[<c15ee31e>] ? parse_early_options+0x25/0x25
> [ ? ?1.214384] ?[<c160e0e8>] ipw_init+0x30/0x75
> [ ? ?1.216356] ?[<c15ee24c>] do_one_initcall+0x86/0x133
> [ ? ?1.218340] ?[<c160e0b8>] ? tun_init+0x8b/0x8b
> [ ? ?1.220315] ?[<c15ee31e>] ? parse_early_options+0x25/0x25
> [ ? ?1.222270] ?[<c15ee393>] kernel_init+0x75/0x10c
> [ ? ?1.224214] ?[<c14349b6>] kernel_thread_helper+0x6/0x10
> [ ? ?1.226124] ---[ end trace 4ef665623022622c ]---
> [ ? ?1.228121] ipw2200: Detected geography ZZR (14 802.11bg channels, 0 802.11a channels)
>
> in dmesg. ?It's a shoot in the dark, but register_netdev() issues
> rtnl_lock() before calling register_netdevice(), so wiphy_register()
> can't possibly acquire the rtnl mutex in the same call chain, or can
> it?
This is fixed here:
http://article.gmane.org/gmane.linux.kernel.wireless.general/77103
josh