3.16.51-rc1 review patch. If anyone has any objections, please let me know.
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From: Johan Hovold johan@kernel.org
commit 90de9634a5d57b92d8af4ec23aa2c9b297ec8168 upstream.
Since commit a8636c89648a ("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 3522bf7bfa24 ("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 6f3c77b040fc ("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: 3522bf7bfa24 ("ARM: OMAP2+: omap_device: maintain sane runtime pm status around suspend/resume") Fixes: a8636c89648a ("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 Signed-off-by: Ben Hutchings ben@decadent.org.uk --- arch/arm/mach-omap2/omap_device.c | 10 ---------- 1 file changed, 10 deletions(-)
--- a/arch/arm/mach-omap2/omap_device.c +++ b/arch/arm/mach-omap2/omap_device.c @@ -640,7 +640,6 @@ static int _od_suspend_noirq(struct devi
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; } @@ -657,15 +656,6 @@ static int _od_resume_noirq(struct devic 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); }