[3.8.y.z,extended,stable] Patch "mmc: sdhci: fix lockdep error in tuning routine" has been added to staging queue

This is a note to let you know that I have just added a patch titled

    mmc: sdhci: fix lockdep error in tuning routine

to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.18.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

From 66f9227239c9bf7d49538cb33712715395319943 Mon Sep 17 00:00:00 2001
From: Aisheng Dong <b29396@freescale.com>
Date: Mon, 23 Dec 2013 19:13:04 +0800
Subject: mmc: sdhci: fix lockdep error in tuning routine

commit 2b35bd83467df6f8284b9148d6f768148c3a5e5f upstream.

The sdhci_execute_tuning routine gets lock separately by
disable_irq(host->irq);
spin_lock(&host->lock);
It will cause the following lockdep error message since the &host->lock
could also be got in irq context.
Use spin_lock_irqsave/spin_unlock_restore instead to get rid of
this error message.

[ INFO: inconsistent lock state ]
3.13.0-rc1+ #287 Not tainted
---------------------------------
inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
kworker/u2:1/33 [HC0[0]:SC0[0]:HE1:SE1] takes:
 (&(&host->lock)->rlock){?.-...}, at: [<8045f7f4>] sdhci_execute_tuning+0x4c/0x710
{IN-HARDIRQ-W} state was registered at:
  [<8005f030>] mark_lock+0x140/0x6ac
  [<80060760>] __lock_acquire+0xb30/0x1cbc
  [<800620d0>] lock_acquire+0x70/0x84
  [<8061d1c8>] _raw_spin_lock+0x30/0x40
  [<804605cc>] sdhci_irq+0x24/0xa68
  [<8006b1d4>] handle_irq_event_percpu+0x54/0x18c
  [<8006b350>] handle_irq_event+0x44/0x64
  [<8006e50c>] handle_fasteoi_irq+0xa0/0x170
  [<8006a8f0>] generic_handle_irq+0x30/0x44
  [<8000f238>] handle_IRQ+0x54/0xbc
  [<8000864c>] gic_handle_irq+0x30/0x64
  [<80013024>] __irq_svc+0x44/0x5c
  [<80329bf4>] dev_vprintk_emit+0x50/0x58
  [<80329c24>] dev_printk_emit+0x28/0x30
  [<80329fec>] __dev_printk+0x4c/0x90
  [<8032a180>] dev_err+0x3c/0x48
  [<802dd4f0>] _regulator_get+0x158/0x1cc
  [<802dd5b4>] regulator_get_optional+0x18/0x1c
  [<80461df4>] sdhci_add_host+0x42c/0xbd8
  [<80464820>] sdhci_esdhc_imx_probe+0x378/0x67c
  [<8032ee88>] platform_drv_probe+0x20/0x50
  [<8032d48c>] driver_probe_device+0x118/0x234
  [<8032d690>] __driver_attach+0x9c/0xa0
  [<8032b89c>] bus_for_each_dev+0x68/0x9c
  [<8032cf44>] driver_attach+0x20/0x28
  [<8032cbc8>] bus_add_driver+0x148/0x1f4
  [<8032dce0>] driver_register+0x80/0x100
  [<8032ee54>] __platform_driver_register+0x50/0x64
  [<8084b094>] sdhci_esdhc_imx_driver_init+0x18/0x20
  [<80008980>] do_one_initcall+0x108/0x16c
  [<8081cca4>] kernel_init_freeable+0x10c/0x1d0
  [<80611b28>] kernel_init+0x10/0x120
  [<8000e9c8>] ret_from_fork+0x14/0x2c
irq event stamp: 805
hardirqs last  enabled at (805): [<8061d43c>] _raw_spin_unlock_irqrestore+0x38/0x4c
hardirqs last disabled at (804): [<8061d2c8>] _raw_spin_lock_irqsave+0x24/0x54
softirqs last  enabled at (570): [<8002b824>] __do_softirq+0x1c4/0x290
softirqs last disabled at (561): [<8002bcf4>] irq_exit+0xb4/0x10c

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

       CPU0
       ----
  lock(&(&host->lock)->rlock);
  <Interrupt>
    lock(&(&host->lock)->rlock);

 *** DEADLOCK ***

2 locks held by kworker/u2:1/33:
 #0:  (kmmcd){.+.+..}, at: [<8003db18>] process_one_work+0x128/0x468
 #1:  ((&(&host->detect)->work)){+.+...}, at: [<8003db18>] process_one_work+0x128/0x468

stack backtrace:
CPU: 0 PID: 33 Comm: kworker/u2:1 Not tainted 3.13.0-rc1+ #287
Workqueue: kmmcd mmc_rescan
Backtrace:
[<80012160>] (dump_backtrace+0x0/0x10c) from [<80012438>] (show_stack+0x18/0x1c)
 r6:bfad0900 r5:00000000 r4:8088ecc8 r3:bfad0900
[<80012420>] (show_stack+0x0/0x1c) from [<806169ec>] (dump_stack+0x84/0x9c)
[<80616968>] (dump_stack+0x0/0x9c) from [<806147b4>] (print_usage_bug+0x260/0x2d0)
 r5:8076ba88 r4:80977410
[<80614554>] (print_usage_bug+0x0/0x2d0) from [<8005f0d0>] (mark_lock+0x1e0/0x6ac)
 r9:8005e678 r8:00000000 r7:bfad0900 r6:00001015 r5:bfad0cd0
r4:00000002
[<8005eef0>] (mark_lock+0x0/0x6ac) from [<80060234>] (__lock_acquire+0x604/0x1cbc)
[<8005fc30>] (__lock_acquire+0x0/0x1cbc) from [<800620d0>] (lock_acquire+0x70/0x84)
[<80062060>] (lock_acquire+0x0/0x84) from [<8061d1c8>] (_raw_spin_lock+0x30/0x40)
 r7:00000000 r6:bfb63000 r5:00000000 r4:bfb60568
[<8061d198>] (_raw_spin_lock+0x0/0x40) from [<8045f7f4>] (sdhci_execute_tuning+0x4c/0x710)
 r4:bfb60000
[<8045f7a8>] (sdhci_execute_tuning+0x0/0x710) from [<80453454>] (mmc_sd_init_card+0x5f8/0x660)
[<80452e5c>] (mmc_sd_init_card+0x0/0x660) from [<80453748>] (mmc_attach_sd+0xb4/0x180)
 r9:bf92d400 r8:8065f364 r7:00061a80 r6:bfb60000 r5:8065f358
r4:bfb60000
[<80453694>] (mmc_attach_sd+0x0/0x180) from [<8044d9f8>] (mmc_rescan+0x284/0x2f0)
 r5:8065f358 r4:bfb602f8
[<8044d774>] (mmc_rescan+0x0/0x2f0) from [<8003db94>] (process_one_work+0x1a4/0x468)
 r8:00000000 r7:bfb55eb0 r6:bf80dc00 r5:bfb602f8 r4:bfb35980
r3:8044d774
[<8003d9f0>] (process_one_work+0x0/0x468) from [<8003e850>] (worker_thread+0x118/0x3e0)
[<8003e738>] (worker_thread+0x0/0x3e0) from [<80044de0>] (kthread+0xd4/0xf0)
[<80044d0c>] (kthread+0x0/0xf0) from [<8000e9c8>] (ret_from_fork+0x14/0x2c)
 r7:00000000 r6:00000000 r5:80044d0c r4:bfb37b40

Signed-off-by: Dong Aisheng <b29396@freescale.com>
Signed-off-by: Chris Ball <chris@printf.net>
[ kamal: backport to 3.8 (no platform_execute_tuning hook) ]
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
 drivers/mmc/host/sdhci.c | 17 ++++++-----------
 1 file changed, 6 insertions(+), 11 deletions(-)

--
1.8.3.2