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authorBin Liu <b-liu@ti.com>2017-03-10 14:43:37 -0600
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-03-31 10:33:43 +0200
commitd6854f591c2209e36b804779eb175d4e1ae1b9d1 (patch)
tree37b1b454dbd5af572c8a462bc3887292e4490a7f
parentca908a9a57e79e2ff44706eb5fc3fda2ee1eb55a (diff)
usb: musb: fix possible spinlock deadlock
commit bc1e2154542071e3cfe1734b143af9b8bdacf8bd upstream. The DSPS glue calls del_timer_sync() in its musb_platform_disable() implementation, which requires the caller to not hold a lock. But musb_remove() calls musb_platform_disable() will musb->lock held. This could causes spinlock deadlock. So change musb_remove() to call musb_platform_disable() without holds musb->lock. This doesn't impact the musb_platform_disable implementation in other glue drivers. root@am335x-evm:~# modprobe -r musb-dsps [ 126.134879] musb-hdrc musb-hdrc.1: remove, state 1 [ 126.140465] usb usb2: USB disconnect, device number 1 [ 126.146178] usb 2-1: USB disconnect, device number 2 [ 126.416985] musb-hdrc musb-hdrc.1: USB bus 2 deregistered [ 126.423943] [ 126.425525] ====================================================== [ 126.431997] [ INFO: possible circular locking dependency detected ] [ 126.438564] 4.11.0-rc1-00003-g1557f13bca04-dirty #77 Not tainted [ 126.444852] ------------------------------------------------------- [ 126.451414] modprobe/778 is trying to acquire lock: [ 126.456523] (((&glue->timer))){+.-...}, at: [<c01b8788>] del_timer_sync+0x0/0xd0 [ 126.464403] [ 126.464403] but task is already holding lock: [ 126.470511] (&(&musb->lock)->rlock){-.-...}, at: [<bf30b7f8>] musb_remove+0x50/0x1 30 [musb_hdrc] [ 126.479965] [ 126.479965] which lock already depends on the new lock. [ 126.479965] [ 126.488531] [ 126.488531] the existing dependency chain (in reverse order) is: [ 126.496368] [ 126.496368] -> #1 (&(&musb->lock)->rlock){-.-...}: [ 126.502968] otg_timer+0x80/0xec [musb_dsps] [ 126.507990] call_timer_fn+0xb4/0x390 [ 126.512372] expire_timers+0xf0/0x1fc [ 126.516754] run_timer_softirq+0x80/0x178 [ 126.521511] __do_softirq+0xc4/0x554 [ 126.525802] irq_exit+0xe8/0x158 [ 126.529735] __handle_domain_irq+0x58/0xb8 [ 126.534583] __irq_usr+0x54/0x80 [ 126.538507] [ 126.538507] -> #0 (((&glue->timer))){+.-...}: [ 126.544636] del_timer_sync+0x40/0xd0 [ 126.549066] musb_remove+0x6c/0x130 [musb_hdrc] [ 126.554370] platform_drv_remove+0x24/0x3c [ 126.559206] device_release_driver_internal+0x14c/0x1e0 [ 126.565225] bus_remove_device+0xd8/0x108 [ 126.569970] device_del+0x1e4/0x308 [ 126.574170] platform_device_del+0x24/0x8c [ 126.579006] platform_device_unregister+0xc/0x20 [ 126.584394] dsps_remove+0x14/0x30 [musb_dsps] [ 126.589595] platform_drv_remove+0x24/0x3c [ 126.594432] device_release_driver_internal+0x14c/0x1e0 [ 126.600450] driver_detach+0x38/0x6c [ 126.604740] bus_remove_driver+0x4c/0xa0 [ 126.609407] SyS_delete_module+0x11c/0x1e4 [ 126.614252] __sys_trace_return+0x0/0x10 Fixes: ea2f35c01d5ea ("usb: musb: Fix sleeping function called from invalid context for hdrc glue") Acked-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Bin Liu <b-liu@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/usb/musb/musb_core.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
index 772f15821242..4387afabebfd 100644
--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -2497,8 +2497,8 @@ static int musb_remove(struct platform_device *pdev)
pm_runtime_get_sync(musb->controller);
musb_host_cleanup(musb);
musb_gadget_cleanup(musb);
- spin_lock_irqsave(&musb->lock, flags);
musb_platform_disable(musb);
+ spin_lock_irqsave(&musb->lock, flags);
musb_generic_disable(musb);
spin_unlock_irqrestore(&musb->lock, flags);
musb_writeb(musb->mregs, MUSB_DEVCTL, 0);