From: Nishanth Menon <nm@xxxxxx> 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] [<c04d079c>] (__irq_svc+0x3c/0x120) from [<c04d0484>] (_raw_spin_unlock_irq+0x28/0x2c) [ 82.023895] [<c04d0484>] (_raw_spin_unlock_irq+0x28/0x2c) from [<c0323234>] (rpm_callback+0x4c/0x68) [ 82.023956] [<c0323234>] (rpm_callback+0x4c/0x68) from [<c0323f7c>] (rpm_resume+0x338/0x53c) [ 82.023956] [<c0323f7c>] (rpm_resume+0x338/0x53c) from [<c03243f4>] (__pm_runtime_resume+0x48/0x60) [ 82.023986] [<c03243f4>] (__pm_runtime_resume+0x48/0x60) from [<c008aee0>] (sr_enable+0xa8/0x19c) [ 82.023986] [<c008aee0>] (sr_enable+0xa8/0x19c) from [<c008b2fc>] (omap_sr_enable+0x50/0x90) [ 82.024017] [<c008b2fc>] (omap_sr_enable+0x50/0x90) from [<c00888c0>] (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 <rnayak@xxxxxx> Signed-off-by: Nishanth Menon <nm@xxxxxx> [khilman@xxxxxx: minor changelog edits] Signed-off-by: Kevin Hilman <khilman@xxxxxx> --- arch/arm/mach-omap2/smartreflex.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/arch/arm/mach-omap2/smartreflex.c b/arch/arm/mach-omap2/smartreflex.c index 2ce2fb7..dc8e86a 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; -- 1.7.6 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
