Commits
Sudeep Holla committed 798523973dc
usb: isp1760: fix possible deadlock in isp1760_udc_irq
Use spin_{un,}lock_irq{save,restore} in isp1760_udc_{start,stop} to
prevent following potentially deadlock scenario between
isp1760_udc_{start,stop} and isp1760_udc_irq :
=================================
[ INFO: inconsistent lock state ]
4.0.0-rc2-00004-gf7bb2ef60173 #51 Not tainted
---------------------------------
inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage.
in:imklog/2118 [HC1[1]:SC0[0]:HE0:SE1] takes:
(&(&udc->lock)->rlock){?.+...}, at: [<c0397a93>] isp1760_udc_irq+0x367/0x9dc
{HARDIRQ-ON-W} state was registered at:
[<c05135b3>] _raw_spin_lock+0x23/0x30
[<c0396b87>] isp1760_udc_start+0x23/0xf8
[<c039dc21>] udc_bind_to_driver+0x71/0xb0
[<c039de4f>] usb_gadget_probe_driver+0x53/0x9c
[<bf80d0df>] usb_composite_probe+0x8a/0xa4 [libcomposite]
[<bf8311a7>] 0xbf8311a7
[<c00088c5>] do_one_initcall+0x8d/0x17c
[<c050b92d>] do_init_module+0x49/0x148
[<c0087323>] load_module+0xb7f/0xbc4
[<c0087471>] SyS_finit_module+0x51/0x74
[<c000d8c1>] ret_fast_syscall+0x1/0x68
irq event stamp: 4966
hardirqs last enabled at (4965): [<c05137df>] _raw_spin_unlock_irq+0x1f/0x24
hardirqs last disabled at (4966): [<c00110b3>] __irq_svc+0x33/0x64
softirqs last enabled at (4458): [<c0023475>] __do_softirq+0x23d/0x2d0
softirqs last disabled at (4389): [<c002380b>] irq_exit+0xef/0x15c
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&(&udc->lock)->rlock);
<Interrupt>
lock(&(&udc->lock)->rlock);
*** DEADLOCK ***
1 lock held by in:imklog/2118:
#0: (&f->f_pos_lock){+.+.+.}, at: [<c010a101>] __fdget_pos+0x31/0x34
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>