diff options
| author | Stephen Warren <swarren@nvidia.com> | 2013-05-06 14:19:19 -0600 |
|---|---|---|
| committer | Stephen Warren <swarren@nvidia.com> | 2013-08-13 12:07:56 -0600 |
| commit | b4f173752a56187bd55752b0474429202f2ab1d3 (patch) | |
| tree | 64b5936abc2c238f5114b42915ba3958c32890af /arch/arm | |
| parent | 0447cfd75a6bad561ebf2b393dcb2263c261b6c5 (diff) | |
| download | talos-obmc-linux-b4f173752a56187bd55752b0474429202f2ab1d3.tar.gz talos-obmc-linux-b4f173752a56187bd55752b0474429202f2ab1d3.zip | |
ARM: tegra: disable LP2 cpuidle state if PCIe is enabled
Tegra20 HW appears to have a bug such that PCIe device interrupts,
whether they are legacy IRQs or MSI, are lost when LP2 is enabled. To
work around this, simply disable LP2 if any PCIe devices with interrupts
are present. Detect this via the IRQ domain map operation. This is
slightly over-conservative; if a device with an interrupt is present but
the driver does not actually use them, LP2 will still be disabled.
However, this is a reasonable trade-off which enables a simpler
workaround.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Diffstat (limited to 'arch/arm')
| -rw-r--r-- | arch/arm/mach-tegra/cpuidle-tegra20.c | 12 | ||||
| -rw-r--r-- | arch/arm/mach-tegra/cpuidle.c | 10 | ||||
| -rw-r--r-- | arch/arm/mach-tegra/cpuidle.h | 1 |
3 files changed, 23 insertions, 0 deletions
diff --git a/arch/arm/mach-tegra/cpuidle-tegra20.c b/arch/arm/mach-tegra/cpuidle-tegra20.c index 706aa4215c36..b82dcaee2ef4 100644 --- a/arch/arm/mach-tegra/cpuidle-tegra20.c +++ b/arch/arm/mach-tegra/cpuidle-tegra20.c @@ -211,6 +211,18 @@ static int tegra20_idle_lp2_coupled(struct cpuidle_device *dev, } #endif +/* + * Tegra20 HW appears to have a bug such that PCIe device interrupts, whether + * they are legacy IRQs or MSI, are lost when LP2 is enabled. To work around + * this, simply disable LP2 if the PCI driver and DT node are both enabled. + */ +void tegra20_cpuidle_pcie_irqs_in_use(void) +{ + pr_info_once( + "Disabling cpuidle LP2 state, since PCIe IRQs are in use\n"); + tegra_idle_driver.states[1].disabled = true; +} + int __init tegra20_cpuidle_init(void) { return cpuidle_register(&tegra_idle_driver, cpu_possible_mask); diff --git a/arch/arm/mach-tegra/cpuidle.c b/arch/arm/mach-tegra/cpuidle.c index e85973cef037..0961dfcf83a4 100644 --- a/arch/arm/mach-tegra/cpuidle.c +++ b/arch/arm/mach-tegra/cpuidle.c @@ -44,3 +44,13 @@ void __init tegra_cpuidle_init(void) break; } } + +void tegra_cpuidle_pcie_irqs_in_use(void) +{ + switch (tegra_chip_id) { + case TEGRA20: + if (IS_ENABLED(CONFIG_ARCH_TEGRA_2x_SOC)) + tegra20_cpuidle_pcie_irqs_in_use(); + break; + } +} diff --git a/arch/arm/mach-tegra/cpuidle.h b/arch/arm/mach-tegra/cpuidle.h index 9ec2c1ab0fa4..c017dab60ffa 100644 --- a/arch/arm/mach-tegra/cpuidle.h +++ b/arch/arm/mach-tegra/cpuidle.h @@ -19,6 +19,7 @@ #ifdef CONFIG_CPU_IDLE int tegra20_cpuidle_init(void); +void tegra20_cpuidle_pcie_irqs_in_use(void); int tegra30_cpuidle_init(void); int tegra114_cpuidle_init(void); void tegra_cpuidle_init(void); |
