| From: Johan Hovold <johan@kernel.org> |
| Date: Thu, 10 Aug 2017 08:06:39 -0700 |
| Subject: ARM: OMAP2+: omap_device: drop broken RPM status update from |
| suspend_noirq |
| |
| 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); |
| } |
| |
