[3.16.y-ckt stable] Patch "mmc: sdhci-s3c: fix runtime PM handling on sdhci_add_host() failure" has been added to staging queue

[Luis Henriques]

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

    mmc: sdhci-s3c: fix runtime PM handling on sdhci_add_host() failure

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt2.

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

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From aadefebf34df8c74cf2aa6e35459e258c85047c0 Mon Sep 17 00:00:00 2001
From: Bartlomiej Zolnierkiewicz <b.zolnierkie at samsung.com>
Date: Thu, 7 Aug 2014 18:07:07 +0200
Subject: mmc: sdhci-s3c: fix runtime PM handling on sdhci_add_host() failure

commit 221414db1934c1c883501998f510bb75acfbaa51 upstream.

Runtime Power Management handling for the sdhci_add_host() failure
case in sdhci_s3c_probe() should match the code in sdhci_s3c_remove()
(which uses pm_runtime_disable() call which matches the earlier
pm_runtime_enable() one).  Fix it.

This patch fixes "BUG: spinlock bad magic on CPU#0, swapper/0/1" and
"Unbalanced pm_runtime_enable!" warnings.

>From the kernel log:
...
[    1.659631] s3c-sdhci 12530000.sdhci: sdhci_add_host() failed
[    1.665096] BUG: spinlock bad magic on CPU#0, swapper/0/1
[    1.670433]  lock: 0xea01e484, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0
[    1.677895] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.16.0-next-20140804-00008-ga59480f-dirty #707
[    1.687037] [<c0013ae4>] (unwind_backtrace) from [<c0010d70>] (show_stack+0x10/0x14)
[    1.694740] [<c0010d70>] (show_stack) from [<c04050c8>] (dump_stack+0x68/0xb8)
[    1.701948] [<c04050c8>] (dump_stack) from [<c0052558>] (do_raw_spin_lock+0x15c/0x1a4)
[    1.709848] [<c0052558>] (do_raw_spin_lock) from [<c040a630>] (_raw_spin_lock_irqsave+0x20/0x28)
[    1.718619] [<c040a630>] (_raw_spin_lock_irqsave) from [<c030d7d0>] (sdhci_do_set_ios+0x1c/0x5cc)
[    1.727464] [<c030d7d0>] (sdhci_do_set_ios) from [<c030ddfc>] (sdhci_runtime_resume_host+0x50/0x104)
[    1.736574] [<c030ddfc>] (sdhci_runtime_resume_host) from [<c02462dc>] (pm_generic_runtime_resume+0x2c/0x40)
[    1.746383] [<c02462dc>] (pm_generic_runtime_resume) from [<c0247898>] (__rpm_callback+0x34/0x70)
[    1.755233] [<c0247898>] (__rpm_callback) from [<c02478fc>] (rpm_callback+0x28/0x88)
[    1.762958] [<c02478fc>] (rpm_callback) from [<c02486f0>] (rpm_resume+0x384/0x4ec)
[    1.770511] [<c02486f0>] (rpm_resume) from [<c02488b0>] (pm_runtime_forbid+0x58/0x64)
[    1.778325] [<c02488b0>] (pm_runtime_forbid) from [<c030ea70>] (sdhci_s3c_probe+0x4a4/0x540)
[    1.786749] [<c030ea70>] (sdhci_s3c_probe) from [<c02429cc>] (platform_drv_probe+0x2c/0x5c)
[    1.795076] [<c02429cc>] (platform_drv_probe) from [<c02415f0>] (driver_probe_device+0x114/0x234)
[    1.803929] [<c02415f0>] (driver_probe_device) from [<c024179c>] (__driver_attach+0x8c/0x90)
[    1.812347] [<c024179c>] (__driver_attach) from [<c023ffb4>] (bus_for_each_dev+0x54/0x88)
[    1.820506] [<c023ffb4>] (bus_for_each_dev) from [<c0240df8>] (bus_add_driver+0xd8/0x1cc)
[    1.828665] [<c0240df8>] (bus_add_driver) from [<c0241db8>] (driver_register+0x78/0xf4)
[    1.836652] [<c0241db8>] (driver_register) from [<c00088a4>] (do_one_initcall+0x80/0x1d0)
[    1.844816] [<c00088a4>] (do_one_initcall) from [<c059ac94>] (kernel_init_freeable+0x108/0x1d4)
[    1.853503] [<c059ac94>] (kernel_init_freeable) from [<c0401300>] (kernel_init+0x8/0xe4)
[    1.861568] [<c0401300>] (kernel_init) from [<c000e538>] (ret_from_fork+0x14/0x3c)
[    1.869582] platform 12530000.sdhci: Driver s3c-sdhci requests probe deferral
...
[    1.997047] s3c-sdhci 12530000.sdhci: Unbalanced pm_runtime_enable!
...
[    2.027235] s3c-sdhci 12530000.sdhci: sdhci_add_host() failed
[    2.032884] platform 12530000.sdhci: Driver s3c-sdhci requests probe deferral
...

Tested on Hardkernel's Exynos4412 based ODROID-U3 board.

Fixes: 9f4e8151dbbc ("mmc: sdhci-s3c: Enable runtime power management")
Cc: Mark Brown <broonie at opensource.wolfsonmicro.com>
Cc: Jaehoon Chung <jh80.chung at samsung.com>
Cc: Ben Dooks <ben-linux at fluff.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie at samsung.com>
Acked-by: Kyungmin Park <kyungmin.park at samsung.com>
Signed-off-by: Ulf Hansson <ulf.hansson at linaro.org>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/mmc/host/sdhci-s3c.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/host/sdhci-s3c.c b/drivers/mmc/host/sdhci-s3c.c
index fa5954a05449..1e47903fa184 100644
--- a/drivers/mmc/host/sdhci-s3c.c
+++ b/drivers/mmc/host/sdhci-s3c.c
@@ -606,8 +606,6 @@ static int sdhci_s3c_probe(struct platform_device *pdev)
 	ret = sdhci_add_host(host);
 	if (ret) {
 		dev_err(dev, "sdhci_add_host() failed\n");
-		pm_runtime_forbid(&pdev->dev);
-		pm_runtime_get_noresume(&pdev->dev);
 		goto err_req_regs;
 	}

@@ -618,6 +616,8 @@ static int sdhci_s3c_probe(struct platform_device *pdev)
 	return 0;

  err_req_regs:
+	pm_runtime_disable(&pdev->dev);
+
  err_no_busclks:
 	clk_disable_unprepare(sc->clk_io);

--
2.1.0