From 7570a333d8b00e7fd4b05d898e353000a70210ce Mon Sep 17 00:00:00 2001 From: MUNEDA Takahiro Date: Thu, 2 Feb 2012 11:09:22 -0500 Subject: [PATCH] PCI: Add pcie_hp=nomsi to disable MSI/MSI-X for pciehp driver Add a parameter to avoid using MSI/MSI-X for PCIe native hotplug; it's known to be buggy on some platforms. In my environment, while shutting down, following stack trace is shown sometimes. irq 16: nobody cared (try booting with the "irqpoll" option) Pid: 1081, comm: reboot Not tainted 3.2.0 #1 Call Trace: [] __report_bad_irq+0x3d/0xe0 [] note_interrupt+0x15c/0x210 [] handle_irq_event_percpu+0xb5/0x210 [] handle_irq_event+0x41/0x70 [] handle_fasteoi_irq+0x55/0xc0 [] handle_irq+0x46/0xb0 [] do_IRQ+0x5d/0xe0 [] common_interrupt+0x6e/0x6e [] ? __do_softirq+0x60/0x210 [] ? hrtimer_interrupt+0x151/0x240 [] call_softirq+0x1c/0x30 [] do_softirq+0x65/0xa0 [] irq_exit+0xbd/0xe0 [] smp_apic_timer_interrupt+0x6e/0x99 [] apic_timer_interrupt+0x6e/0x80 [] ? _raw_spin_unlock_irqrestore+0x11/0x20 [] pci_bus_write_config_word+0x6c/0x80 [] pci_intx+0x52/0xa0 [] pci_intx_for_msi+0x1d/0x30 [] pci_msi_shutdown+0x7b/0x110 [] pci_device_shutdown+0x34/0x50 [] device_shutdown+0x2f/0x140 [] kernel_restart_prepare+0x31/0x40 [] kernel_restart+0x16/0x60 [] sys_reboot+0x1ad/0x220 [] ? do_page_fault+0x1e0/0x460 [] ? __sync_filesystem+0x90/0x90 [] ? __cond_resched+0x2a/0x40 [] ? _cond_resched+0x30/0x40 [] ? iterate_supers+0xb7/0xd0 [] system_call_fastpath+0x16/0x1b handlers: [] usb_hcd_irq [] usb_hcd_irq [] usb_hcd_irq Disabling IRQ #16 An un-wanted interrupt is generated when PCI driver switches from MSI/MSI-X to INTx while shutting down the device. The interrupt does not happen if MSI/MSI-X is not used on the device. I confirmed that this problem does not happen if pcie_hp=nomsi was specified and hotplug operation worked fine as usual. v2: Automatically disable MSI/MSI-X against following device: PCI bridge: Integrated Device Technology, Inc. Device 807f (rev 02) v3: Based on the review comment, combile the if statements. v4: Removed module parameter. Move some code to build pciehp as a module. Move device specific code to driver/pci/quirks.c. v5: Drop a device specific code until getting a vendor statement. Reviewed-by: Kenji Kaneshige Signed-off-by: MUNEDA Takahiro Signed-off-by: Jesse Barnes --- Documentation/kernel-parameters.txt | 4 ++++ drivers/pci/pcie/portdrv.h | 12 ++++++++++++ drivers/pci/pcie/portdrv_core.c | 16 ++++++++++++++-- 3 files changed, 30 insertions(+), 2 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 033d4e6..7fb7a4b 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2118,6 +2118,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. force Enable ASPM even on devices that claim not to support it. WARNING: Forcing ASPM on may cause system lockups. + pcie_hp= [PCIE] PCI Express Hotplug driver options: + nomsi Do not use MSI for PCI Express Native Hotplug (this + makes all PCIe ports use INTx for hotplug services). + pcie_ports= [PCIE] PCIe ports handling: auto Ask the BIOS whether or not to use native PCIe services associated with PCIe ports (PME, hot-plug, AER). Use diff --git a/drivers/pci/pcie/portdrv.h b/drivers/pci/pcie/portdrv.h index bd00a01..eea2ca2 100644 --- a/drivers/pci/pcie/portdrv.h +++ b/drivers/pci/pcie/portdrv.h @@ -34,6 +34,18 @@ struct pci_dev; extern void pcie_clear_root_pme_status(struct pci_dev *dev); +#ifdef CONFIG_HOTPLUG_PCI_PCIE +extern bool pciehp_msi_disabled; + +static inline bool pciehp_no_msi(void) +{ + return pciehp_msi_disabled; +} + +#else /* !CONFIG_HOTPLUG_PCI_PCIE */ +static inline bool pciehp_no_msi(void) { return false; } +#endif /* !CONFIG_HOTPLUG_PCI_PCIE */ + #ifdef CONFIG_PCIE_PME extern bool pcie_pme_msi_disabled; diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c index 595654a..2f589a5 100644 --- a/drivers/pci/pcie/portdrv_core.c +++ b/drivers/pci/pcie/portdrv_core.c @@ -19,6 +19,17 @@ #include "../pci.h" #include "portdrv.h" +bool pciehp_msi_disabled; + +static int __init pciehp_setup(char *str) +{ + if (!strncmp(str, "nomsi", 5)) + pciehp_msi_disabled = true; + + return 1; +} +__setup("pcie_hp=", pciehp_setup); + /** * release_pcie_device - free PCI Express port service device structure * @dev: Port service device to release @@ -189,8 +200,9 @@ static int init_service_irqs(struct pci_dev *dev, int *irqs, int mask) { int i, irq = -1; - /* We have to use INTx if MSI cannot be used for PCIe PME. */ - if ((mask & PCIE_PORT_SERVICE_PME) && pcie_pme_no_msi()) { + /* We have to use INTx if MSI cannot be used for PCIe PME or pciehp. */ + if (((mask & PCIE_PORT_SERVICE_PME) && pcie_pme_no_msi()) || + ((mask & PCIE_PORT_SERVICE_HP) && pciehp_no_msi())) { if (dev->pin) irq = dev->irq; goto no_msi; -- 2.7.4