HACK: ARM: dts: exynos4412-odroid: leave SDHC regulators always on

There are some stability issues with SDHC detection on boot. To
minimize potential sources for this issue, leave the corresponding
regulators always on for now.
mmc: core: sdio: Fix unconditional wake_up_process() on sdio thread

commit dea67c4ec8218b301d7cac7ee6e63dac0bc566cb upstream.

781e989cf59 ("mmc: sdhci: convert to new SDIO IRQ handling") and
bf3b5ec66bd ("mmc: sdio_irq: rework sdio irq handling") disabled
the use of our own custom threaded IRQ handler, but left in an
unconditional wake_up_process() on that handler at resume-time.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=80151

In addition, the check for MMC_CAP_SDIO_IRQ capability is added
before enable sdio IRQ.

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Chris Ball <chris@printf.net>
Signed-off-by: Fu Zhonghui <zhonghui.fu@linux.intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mmc: don't request CD IRQ until mmc_start_host()

commit d4d11449088ee9aca16fd1884b852b8b73a4bda1 upstream.

As soon as the CD IRQ is requested, it can trigger, since it's an
externally controlled event. If it does, delayed_work host->detect will
be scheduled.

Many host controller probe()s are roughly structured as:

*_probe() {
    host = sdhci_pltfm_init();
    mmc_of_parse(host->mmc);
    rc = sdhci_add_host(host);
    if (rc) {
        sdhci_pltfm_free();
        return rc;
    }

In 3.17, CD IRQs can are enabled quite early via *_probe() ->
mmc_of_parse() -> mmc_gpio_request_cd() -> mmc_gpiod_request_cd_irq().

Note that in linux-next, mmc_of_parse() calls mmc_gpio*d*_request_cd()
rather than mmc_gpio_request_cd(), and mmc_gpio*d*_request_cd() doesn't
call mmc_gpiod_request_cd_irq(). However, this issue still exists if
mmc_gpio_request_cd() is called directly before mmc_start_host().

sdhci_add_host() may fail part way through (e.g. due to deferred
probe for a vmmc regulator), and sdhci_pltfm_free() does nothing to
unrequest the CD IRQ nor cancel the delayed_work. sdhci_pltfm_free() is
coded to assume that if sdhci_add_host() failed, then the delayed_work
cannot (or should not) have been triggered.

This can lead to the following with CONFIG_DEBUG_OBJECTS_* enabled, when
kfree(host) is eventually called inside sdhci_pltfm_free():

WARNING: CPU: 2 PID: 6 at lib/debugobjects.c:263 debug_print_object+0x8c/0xb4()
ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x18

The object being complained about is host->detect.

There's no need to request the CD IRQ so early; mmc_start_host() already
requests it. For most SDHCI hosts at least, the typical call path that
does this is: *_probe() -> sdhci_add_host() -> mmc_add_host() ->
mmc_start_host(). Therefore, remove the call to mmc_gpiod_request_cd_irq()
from mmc_gpio_request_cd(). This also matches mmc_gpio*d*_request_cd(),
which already doesn't call mmc_gpiod_request_cd_irq().

However, some host controller drivers call mmc_gpio_request_cd() after
mmc_start_host() has already been called, and assume that this will also
call mmc_gpiod_request_cd_irq(). Update those drivers to explicitly call
mmc_gpiod_request_cd_irq() themselves. Ideally, these drivers should be
modified to move their call to mmc_gpio_request_cd() before their call
to mmc_add_host(). However that's too large a change for stable.

This solves the problem (eliminates the kernel error message above),
since it guarantees that the IRQ can't trigger before mmc_start_host()
is called.

The critical point here is that once sdhci_add_host() calls
mmc_add_host() -> mmc_start_host(), sdhci_add_host() is coded not to
fail. In other words, if there's a chance that mmc_start_host() may have
been called, and CD IRQs triggered, and the delayed_work scheduled,
sdhci_add_host() won't fail, and so cleanup is no longer via
sdhci_pltfm_free() (which doesn't free the IRQ or cancel the work queue)
but instead must be via sdhci_remove_host(), which calls mmc_remove_host()
-> mmc_stop_host(), which does free the IRQ and cancel the work queue.

CC: Russell King <linux@arm.linux.org.uk>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexandre Courbot <acourbot@nvidia.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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@opensource.wolfsonmicro.com>
Cc: Jaehoon Chung <jh80.chung@samsung.com>
Cc: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>