diff options
| author | Grygorii Strashko <grygorii.strashko@ti.com> | 2015-12-10 21:18:20 +0200 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2016-01-06 16:08:02 -0600 |
| commit | 8ff0ef996ca00028519c70e8d51d32bd37eb51dc (patch) | |
| tree | 44f51fc6086caf0c4f2971de66356d5334d847c2 /drivers/pci/host/pcie-xilinx.c | |
| parent | 1ec218373b8ebda821aec00bb156a9c94fad9cd4 (diff) | |
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>
Diffstat (limited to 'drivers/pci/host/pcie-xilinx.c')
| -rw-r--r-- | drivers/pci/host/pcie-xilinx.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/pci/host/pcie-xilinx.c b/drivers/pci/host/pcie-xilinx.c index 3c7a0d580b1e..4cfa46360d12 100644 --- a/drivers/pci/host/pcie-xilinx.c +++ b/drivers/pci/host/pcie-xilinx.c @@ -781,7 +781,8 @@ static int xilinx_pcie_parse_dt(struct xilinx_pcie_port *port) 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; |