From 185e3dead35dacb79c8cca1073fd67a26d09a0d7 Mon Sep 17 00:00:00 2001 From: Li Yang Date: Thu, 29 May 2008 21:04:45 +0800 Subject: [PATCH] USB: fsl_usb2_udc: fix recursive lock UDC needs to release lock before calling out to gadget driver, since it may need to reenter. The change fixes kernel BUG observed on rt kernel. > kernel BUG at kernel/rtmutex.c:683! > stopped custom tracer. > Oops: Exception in kernel mode, sig: 5 [#1] > PREEMPT MPC834x ITX > NIP: c021629c LR: c0216270 CTR: 00000000 > REGS: df761d70 TRAP: 0700 Not tainted (2.6.23.9-rt13) > MSR: 00021032 CR: 28000022 XER: 00000000 > TASK = df632080[241] 'IRQ-38' THREAD: df760000 > GPR00: 00000001 df761e20 df632080 00000000 11111111 00000000 df761e6c > 00000000 > GPR08: df761e48 00000000 df761e50 00000000 80000000 ede5cdde 1fffd000 > 00800000 > GPR16: ffffffff 00000000 007fff00 00000040 00000000 007ffeb0 00000000 > 1fff8b08 > GPR24: 00000000 00000026 00000000 df79a320 c026b2e8 c02240bc 00009032 > df79a320 > NIP [c021629c] rt_spin_lock_slowlock+0x9c/0x200 > LR [c0216270] rt_spin_lock_slowlock+0x70/0x200 > Call Trace: > [df761e20] [c0216270] rt_spin_lock_slowlock+0x70/0x200 (unreliable) > [df761e90] [c0182828] fsl_ep_disable+0xcc/0x154 > [df761eb0] [c0184d30] eth_reset_config+0x88/0x1d0 > [df761ed0] [c0184ec0] eth_disconnect+0x48/0x64 > [df761ef0] [c01831a4] reset_queues+0x60/0x78 > [df761f00] [c0183b74] fsl_udc_irq+0x9b8/0xa58 > [df761f50] [c003ef30] handle_IRQ_event+0x64/0x100 > [df761f80] [c003f758] thread_simple_irq+0x6c/0xc8 > [df761fa0] [c003f888] do_irqd+0xd4/0x2e4 > [df761fd0] [c0032284] kthread+0x50/0x8c > [df761ff0] [c000f9b4] kernel_thread+0x44/0x60 Signed-off-by: Li Yang Cc: Eugene T. Bordenkircher Acked-by: David Brownell Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/fsl_usb2_udc.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/usb/gadget/fsl_usb2_udc.c b/drivers/usb/gadget/fsl_usb2_udc.c index 651b8270139..18687543d7f 100644 --- a/drivers/usb/gadget/fsl_usb2_udc.c +++ b/drivers/usb/gadget/fsl_usb2_udc.c @@ -1627,7 +1627,9 @@ static int reset_queues(struct fsl_udc *udc) udc_reset_ep_queue(udc, pipe); /* report disconnect; the driver is already quiesced */ + spin_unlock(&udc->lock); udc->driver->disconnect(&udc->gadget); + spin_lock(&udc->lock); return 0; } -- 2.20.1