From e13d8f383985b7ab8c859c1fa327e9b3d201894e Mon Sep 17 00:00:00 2001 From: Nishanth Menon Date: Sat, 9 Jul 2011 14:37:21 -0700 Subject: [PATCH] OMAP3+: SR: ensure pm-runtime callbacks can be invoked with IRQs disabled SmartReflex should be disabled while entering low power mode due to a) SmartReflex values are not defined for retention voltage, further b) with SmartReflex enabled, if CPU enters lower c-states, FSM will try to bump the voltage to current OPP's voltage for which it has entered c-state; hence SmartReflex needs to be disabled for MPU, CORE and IVA voltage domains in idle path before enabling auto retention voltage achievement on the device. However, since the current pm_runtime setup for SmartReflex devices are setup to allow callbacks to be invoked with interrupts enabled, calling SmartReflex enable/disable from other contexts such as idle paths where preemption is disabled causes warnings such as the following indicating of a potential race. [ 82.023895] [] (__irq_svc+0x3c/0x120) from [] (_raw_spin_unlock_irq+0x28/0x2c) [ 82.023895] [] (_raw_spin_unlock_irq+0x28/0x2c) from [] (rpm_callback+0x4c/0x68) [ 82.023956] [] (rpm_callback+0x4c/0x68) from [] (rpm_resume+0x338/0x53c) [ 82.023956] [] (rpm_resume+0x338/0x53c) from [] (__pm_runtime_resume+0x48/0x60) [ 82.023986] [] (__pm_runtime_resume+0x48/0x60) from [] (sr_enable+0xa8/0x19c) [ 82.023986] [] (sr_enable+0xa8/0x19c) from [] (omap_sr_enable+0x50/0x90) [ 82.024017] [] (omap_sr_enable+0x50/0x90) from [] (omap4_enter_sleep+0x138/0x168) Instead, we use pm_runtime_irq_safe to tell the PM core that callbacks can be invoked in interrupt disabled contexts. Acked-by: Rajendra Nayak Signed-off-by: Nishanth Menon [khilman@ti.com: minor changelog edits] Signed-off-by: Kevin Hilman --- arch/arm/mach-omap2/smartreflex.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arm/mach-omap2/smartreflex.c b/arch/arm/mach-omap2/smartreflex.c index 2ce2fb7664bc..dc8e86a54ac5 100644 --- a/arch/arm/mach-omap2/smartreflex.c +++ b/arch/arm/mach-omap2/smartreflex.c @@ -860,6 +860,7 @@ static int __init omap_sr_probe(struct platform_device *pdev) irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0); pm_runtime_enable(&pdev->dev); + pm_runtime_irq_safe(&pdev->dev); sr_info->pdev = pdev; sr_info->srid = pdev->id; -- GitLab