5 files changed, 47 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);
diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c
index ad95c406a6d0..7356741de36b 100644
--- a/drivers/pci/host/pci-tegra.c
+++ b/drivers/pci/host/pci-tegra.c
@@ -41,6 +41,7 @@
 #include <linux/platform_device.h>
 #include <linux/sizes.h>
 #include <linux/slab.h>
+#include <linux/tegra-cpuidle.h>
 #include <linux/tegra-powergate.h>
 #include <linux/vmalloc.h>
 #include <linux/regulator/consumer.h>
@@ -636,6 +637,8 @@ static int tegra_pcie_map_irq(const struct pci_dev *pdev, u8 slot, u8 pin)
 {
         struct tegra_pcie *pcie = sys_to_pcie(pdev->bus->sysdata);
 
+        tegra_cpuidle_pcie_irqs_in_use();
+
         return pcie->irq;
 }
 
@@ -1221,6 +1224,8 @@ static int tegra_msi_map(struct irq_domain *domain, unsigned int irq,
         irq_set_chip_data(irq, domain->host_data);
         set_irq_flags(irq, IRQF_VALID);
 
+        tegra_cpuidle_pcie_irqs_in_use();
+
         return 0;
 }
 
diff --git a/include/linux/tegra-cpuidle.h b/include/linux/tegra-cpuidle.h
new file mode 100644
index 000000000000..dda3647242a4
--- /dev/null
+++ b/include/linux/tegra-cpuidle.h
@@ -0,0 +1,19 @@
+/*
+ * Copyright (c) 2013, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+
+#ifndef __LINUX_TEGRA_CPUIDLE_H__
+#define __LINUX_TEGRA_CPUIDLE_H__
+
+void tegra_cpuidle_pcie_irqs_in_use(void);
+
+#endif