From a0806f9eed23a5d317e8591e06bc3ebffdbd36e8 Mon Sep 17 00:00:00 2001
From: Stephen Boyd <sboyd@codeaurora.org>
Date: Wed, 18 Apr 2012 20:00:23 -0700
Subject: [PATCH] USB: OTG: msm: Fix inconsistent lockdep state warning

=================================
[ INFO: inconsistent lock state ]
3.0.21-g51ce160-00021-g8b33780-dirty #2904
---------------------------------
inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W}

kworker/0:1/32 [HC0[0]:SC0[0]:HE1:SE1] takes:
 (&irq_desc_lock_class){?.....}, at: [<c01cfd10>] irq_read_line+0x3c/0x80
{IN-HARDIRQ-W} state was registered at:
  [<c01b8768>] __lock_acquire+0x704/0x9f8
  [<c01b9034>] lock_acquire+0x10c/0x130
  [<c0833ac8>] _raw_spin_lock+0x44/0x54
  [<c01d1c30>] handle_fasteoi_irq+0x14/0x108
  [<c01ce8ac>] generic_handle_irq+0x28/0x3c
  [<c0106f6c>] handle_IRQ+0x7c/0xc0
  [<c0100458>] gic_handle_irq+0xac/0x104
  [<c0834798>] __irq_svc+0x58/0x8c
  [<c01070b4>] default_idle+0x28/0x2c
  [<c010742c>] cpu_idle+0x8c/0xf4
  [<c0808ddc>] rest_init+0xd8/0x100
  [<c0008a90>] start_kernel+0x464/0x4d8
  [<8020803c>] 0x8020803c

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&irq_desc_lock_class);
  <Interrupt>
    lock(&irq_desc_lock_class);

 *** DEADLOCK ***

2 locks held by kworker/0:1/32:
 #0:  (events_nrt){.+.+..}, at: [<c019c49c>] process_one_work+0x1f8/0x518
 #1:  ((&motg->sm_work)){+.+...}, at: [<c019c49c>] process_one_work+0x1f8/0x518

stack backtrace:
[<c010c798>] (unwind_backtrace+0x0/0x12c) from [<c01b53bc>]
[<c01b53bc>] (print_usage_bug+0x248/0x2ac) from [<c01b5804>]
[<c01b5804>] (mark_lock+0x3e4/0x6ec) from [<c01b87f4>]
[<c01b87f4>] (__lock_acquire+0x790/0x9f8) from [<c01b9034>]
[<c01b9034>] (lock_acquire+0x10c/0x130) from [<c0833ac8>]
[<c0833ac8>] (_raw_spin_lock+0x44/0x54) from [<c01cfd10>]
[<c01cfd10>] (irq_read_line+0x3c/0x80) from [<c04e79b8>]
[<c04e79b8>] (msm_otg_sm_work+0x1a0/0x1510) from [<c019c57c>]
[<c019c57c>] (process_one_work+0x2d8/0x518) from [<c019cb94>]
[<c019cb94>] (worker_thread+0x220/0x3a0) from [<c01a2a80>]
[<c01a2a80>] (kthread+0x88/0x94) from [<c0107008>]

Change-Id: I7966d183cad54758508cb9635ebe3f31fba408b9
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
---
 drivers/usb/otg/msm_otg.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/usb/otg/msm_otg.c b/drivers/usb/otg/msm_otg.c
index 40089adfec0..55a45d9a4c8 100644
--- a/drivers/usb/otg/msm_otg.c
+++ b/drivers/usb/otg/msm_otg.c
@@ -1995,10 +1995,13 @@ static void msm_otg_init_sm(struct msm_otg *motg)
 				clear_bit(B_SESS_VLD, &motg->inputs);
 		} else if (pdata->otg_control == OTG_PMIC_CONTROL) {
 			if (pdata->pmic_id_irq) {
+				unsigned long flags;
+				local_irq_save(flags);
 				if (irq_read_line(pdata->pmic_id_irq))
 					set_bit(ID, &motg->inputs);
 				else
 					clear_bit(ID, &motg->inputs);
+				local_irq_restore(flags);
 			}
 			/*
 			 * VBUS initial state is reported after PMIC