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ARM: OMAP2+: omap_device: drop broken RPM status update from suspend_noirq 

Since commit a8636c8964 ("PM / Runtime: Don't allow to suspend a
device with an active child"), which went into 4.10, it is no longer
permitted to set RPM_SUSPENDED state for a device with active children
(unless power.ignore_children is set).

This specifically means that the attempts to do just that from the omap
pm-domain suspend_noirq callback have since been failing whenever a
child is active, for example:

  am335x-usb-childs 47400000.usb: runtime PM trying to suspend
    device but active child

Silence this warning by dropping the broken pm_runtime_set_suspended()
call from the omap suspend_noirq callback along with the redundant
pm_runtime_set_active() in resume_noirq.

This effectively reverts commit 3522bf7bfa ("ARM: OMAP2+: omap_device:
maintain sane runtime pm status around suspend/resume"), which started
updating the RPM state after the runtime_suspend callback (!) for active
omap devices had been called during system suspend. The rationale was
that a later pm_runtime_get_sync() would then fail (even after runtime
pm had been disabled) and that this in turn would avoid any external
aborts when accessing registers with clocks disabled. (See also commit
6f3c77b040 ("PM / Runtime: let rpm_resume() succeed if RPM_ACTIVE,
even when disabled, v2").

But during the suspend_noirq phase all children would already have been
suspended and their drivers would specifically not attempt any further
register accesses. And if this was all just a workaround for random
device drivers doing cross-tree calls during system suspend, those
drivers should be fixed and updated to explicitly model such
dependencies using device-links instead (and either way, any such calls
have been causing crashes since 4.10).

Fixes: 3522bf7bfa ("ARM: OMAP2+: omap_device: maintain sane runtime pm status around suspend/resume")
Fixes: a8636c8964 ("PM / Runtime: Don't allow to suspend a device with an active child")
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Dave Gerlach <d-gerlach@ti.com>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Nishanth Menon <nm@ti.com>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Tested-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
This commit is contained in:
Johan Hovold 2017-08-10 08:06:39 -07:00 committed by Tony Lindgren
parent 672647afab
commit 90de9634a5
1 changed files with 0 additions and 10 deletions
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10
arch/arm/mach-omap2/omap_device.c
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@ -672,7 +672,6 @@ static int _od_suspend_noirq(struct device *dev)
if (!ret && !pm_runtime_status_suspended(dev)) {
if (pm_generic_runtime_suspend(dev) == 0) {
pm_runtime_set_suspended(dev);
omap_device_idle(pdev);
od->flags |= OMAP_DEVICE_SUSPENDED;
}
@ -689,15 +688,6 @@ static int _od_resume_noirq(struct device *dev)
if (od->flags & OMAP_DEVICE_SUSPENDED) {
od->flags &= ~OMAP_DEVICE_SUSPENDED;
omap_device_enable(pdev);
/*
* XXX: we run before core runtime pm has resumed itself. At
* this point in time, we just restore the runtime pm state and
* considering symmetric operations in resume, we donot expect
* to fail. If we failed, something changed in core runtime_pm
* framework OR some device driver messed things up, hence, WARN
*/
WARN(pm_runtime_set_active(dev),
"Could not set %s runtime state active\n", dev_name(dev));
pm_generic_runtime_resume(dev);
}