PCI: host: Mark PCIe/PCI (MSI) IRQ cascade handlers as IRQF_NO_THREAD
On -RT and if kernel is booting with "threadirqs" cmd line parameter,
PCIe/PCI (MSI) IRQ cascade handlers (like dra7xx_pcie_msi_irq_handler())
will be forced threaded and, as result, will generate warnings like this:
WARNING: CPU: 1 PID: 82 at kernel/irq/handle.c:150 handle_irq_event_percpu+0x14c/0x174()
irq 460 handler irq_default_primary_handler+0x0/0x14 enabled interrupts
Backtrace:
(warn_slowpath_common) from (warn_slowpath_fmt+0x38/0x40)
(warn_slowpath_fmt) from (handle_irq_event_percpu+0x14c/0x174)
(handle_irq_event_percpu) from (handle_irq_event+0x84/0xb8)
(handle_irq_event) from (handle_simple_irq+0x90/0x118)
(handle_simple_irq) from (generic_handle_irq+0x30/0x44)
(generic_handle_irq) from (dra7xx_pcie_msi_irq_handler+0x7c/0x8c)
(dra7xx_pcie_msi_irq_handler) from (irq_forced_thread_fn+0x28/0x5c)
(irq_forced_thread_fn) from (irq_thread+0x128/0x204)
This happens because all of them invoke generic_handle_irq() from the
requested handler. generic_handle_irq() grabs raw_locks and thus needs to
run in raw-IRQ context.
This issue was originally reproduced on TI dra7-evem, but, as was
identified during discussion [1], other hosts can also suffer from this
issue. Fix all them at once by marking PCIe/PCI (MSI) IRQ cascade handlers
IRQF_NO_THREAD explicitly.
[1] http://lkml.kernel.org/r/1448027966-21610-1-git-send-email-grygorii.strashko@ti.com
[bhelgaas: add stable tag, fix typos]
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Lucas Stach <l.stach@pengutronix.de> (for imx6)
CC: stable@vger.kernel.org
CC: Kishon Vijay Abraham I <kishon@ti.com>
CC: Jingoo Han <jingoohan1@gmail.com>
CC: Kukjin Kim <kgene@kernel.org>
CC: Krzysztof Kozlowski <k.kozlowski@samsung.com>
CC: Richard Zhu <Richard.Zhu@freescale.com>
CC: Thierry Reding <thierry.reding@gmail.com>
CC: Stephen Warren <swarren@wwwdotorg.org>
CC: Alexandre Courbot <gnurou@gmail.com>
CC: Simon Horman <horms@verge.net.au>
CC: Pratyush Anand <pratyush.anand@gmail.com>
CC: Michal Simek <michal.simek@xilinx.com>
CC: "Sören Brinkmann" <soren.brinkmann@xilinx.com>
CC: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
diff --git a/drivers/pci/host/pci-dra7xx.c b/drivers/pci/host/pci-dra7xx.c
index 8c36880..923607b 100644
--- a/drivers/pci/host/pci-dra7xx.c
+++ b/drivers/pci/host/pci-dra7xx.c
@@ -302,7 +302,8 @@
}
ret = devm_request_irq(&pdev->dev, pp->irq,
- dra7xx_pcie_msi_irq_handler, IRQF_SHARED,
+ dra7xx_pcie_msi_irq_handler,
+ IRQF_SHARED | IRQF_NO_THREAD,
"dra7-pcie-msi", pp);
if (ret) {
dev_err(&pdev->dev, "failed to request irq\n");
diff --git a/drivers/pci/host/pci-exynos.c b/drivers/pci/host/pci-exynos.c
index 01095e1..d997d22 100644
--- a/drivers/pci/host/pci-exynos.c
+++ b/drivers/pci/host/pci-exynos.c
@@ -522,7 +522,8 @@
ret = devm_request_irq(&pdev->dev, pp->msi_irq,
exynos_pcie_msi_irq_handler,
- IRQF_SHARED, "exynos-pcie", pp);
+ IRQF_SHARED | IRQF_NO_THREAD,
+ "exynos-pcie", pp);
if (ret) {
dev_err(&pdev->dev, "failed to request msi irq\n");
return ret;
diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c
index 22e8224..9ce7cd1 100644
--- a/drivers/pci/host/pci-imx6.c
+++ b/drivers/pci/host/pci-imx6.c
@@ -537,7 +537,8 @@
ret = devm_request_irq(&pdev->dev, pp->msi_irq,
imx6_pcie_msi_handler,
- IRQF_SHARED, "mx6-pcie-msi", pp);
+ IRQF_SHARED | IRQF_NO_THREAD,
+ "mx6-pcie-msi", pp);
if (ret) {
dev_err(&pdev->dev, "failed to request MSI irq\n");
return ret;
diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c
index 3018ae5..3032311 100644
--- a/drivers/pci/host/pci-tegra.c
+++ b/drivers/pci/host/pci-tegra.c
@@ -1288,7 +1288,7 @@
msi->irq = err;
- err = request_irq(msi->irq, tegra_pcie_msi_irq, 0,
+ err = request_irq(msi->irq, tegra_pcie_msi_irq, IRQF_NO_THREAD,
tegra_msi_irq_chip.name, pcie);
if (err < 0) {
dev_err(&pdev->dev, "failed to request IRQ: %d\n", err);
diff --git a/drivers/pci/host/pcie-rcar.c b/drivers/pci/host/pcie-rcar.c
index f4fa6c5..414c336 100644
--- a/drivers/pci/host/pcie-rcar.c
+++ b/drivers/pci/host/pcie-rcar.c
@@ -720,14 +720,16 @@
/* Two irqs are for MSI, but they are also used for non-MSI irqs */
err = devm_request_irq(&pdev->dev, msi->irq1, rcar_pcie_msi_irq,
- IRQF_SHARED, rcar_msi_irq_chip.name, pcie);
+ IRQF_SHARED | IRQF_NO_THREAD,
+ rcar_msi_irq_chip.name, pcie);
if (err < 0) {
dev_err(&pdev->dev, "failed to request IRQ: %d\n", err);
goto err;
}
err = devm_request_irq(&pdev->dev, msi->irq2, rcar_pcie_msi_irq,
- IRQF_SHARED, rcar_msi_irq_chip.name, pcie);
+ IRQF_SHARED | IRQF_NO_THREAD,
+ rcar_msi_irq_chip.name, pcie);
if (err < 0) {
dev_err(&pdev->dev, "failed to request IRQ: %d\n", err);
goto err;
diff --git a/drivers/pci/host/pcie-spear13xx.c b/drivers/pci/host/pcie-spear13xx.c
index b95b756..a6cd823 100644
--- a/drivers/pci/host/pcie-spear13xx.c
+++ b/drivers/pci/host/pcie-spear13xx.c
@@ -279,7 +279,8 @@
return -ENODEV;
}
ret = devm_request_irq(dev, pp->irq, spear13xx_pcie_irq_handler,
- IRQF_SHARED, "spear1340-pcie", pp);
+ IRQF_SHARED | IRQF_NO_THREAD,
+ "spear1340-pcie", pp);
if (ret) {
dev_err(dev, "failed to request irq %d\n", pp->irq);
return ret;
diff --git a/drivers/pci/host/pcie-xilinx.c b/drivers/pci/host/pcie-xilinx.c
index 3c7a0d5..4cfa463 100644
--- a/drivers/pci/host/pcie-xilinx.c
+++ b/drivers/pci/host/pcie-xilinx.c
@@ -781,7 +781,8 @@
port->irq = irq_of_parse_and_map(node, 0);
err = devm_request_irq(dev, port->irq, xilinx_pcie_intr_handler,
- IRQF_SHARED, "xilinx-pcie", port);
+ IRQF_SHARED | IRQF_NO_THREAD,
+ "xilinx-pcie", port);
if (err) {
dev_err(dev, "unable to request irq %d\n", port->irq);
return err;