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Commit 1e447c57 authored by Bjorn Helgaas's avatar Bjorn Helgaas Committed by Bjorn Helgaas
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PCI/portdrv: Remove "pcie_hp=nomsi" kernel parameter 



7570a333 ("PCI: Add pcie_hp=nomsi to disable MSI/MSI-X for pciehp
driver") added the "pcie_hp=nomsi" kernel parameter to work around this
error on shutdown:

  irq 16: nobody cared (try booting with the "irqpoll" option)
  Pid: 1081, comm: reboot Not tainted 3.2.0 #1
  ...
  Disabling IRQ #16

This happened on an unspecified system (possibly involving the Integrated
Device Technology, Inc. Device 807f bridge) where "an un-wanted interrupt
is generated when PCI driver switches from MSI/MSI-X to INTx while shutting
down the device."

The implication was that the device was buggy, but it is normal for a
device to use INTx after MSI/MSI-X have been disabled.  The only problem
was that the driver was still attached and it wasn't prepared for INTx
interrupts.  Prarit Bhargava fixed this issue with fda78d7a ("PCI/MSI:
Stop disabling MSI/MSI-X in pci_device_shutdown()").

There is no automated way to set this parameter, so it's not very useful
for distributions or end users.  It's really only useful for debugging, and
we have "pci=nomsi" for that purpose.

Revert 7570a333 to remove the "pcie_hp=nomsi" parameter.

Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
CC: MUNEDA Takahiro <muneda.takahiro@jp.fujitsu.com>
CC: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
CC: Prarit Bhargava <prarit@redhat.com>
parent 1b64cb87

Documentation/admin-guide/kernel-parameters.txt

+0 −4
Original line number Diff line number Diff line
@@ -3130,10 +3130,6 @@ 
		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

drivers/pci/pcie/portdrv.h

+0 −12
Original line number Diff line number Diff line
@@ -91,18 +91,6 @@ void pcie_port_bus_unregister(void); 


struct pci_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;

drivers/pci/pcie/portdrv_core.c

+3 −17
Original line number Diff line number Diff line
@@ -20,17 +20,6 @@ 
#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
@@ -168,16 +157,13 @@ static int pcie_init_service_irqs(struct pci_dev *dev, int *irqs, int mask) 
		irqs[i] = -1;



	/*

	 * If we support PME or hotplug, but we can't use MSI/MSI-X for

	 * them, we have to fall back to INTx or other interrupts, e.g., a

	 * system shared interrupt.

	 * If we support PME but can't use MSI/MSI-X for it, we have to

	 * fall back to INTx or other interrupts, e.g., a system shared

	 * interrupt.

	 */

	if ((mask & PCIE_PORT_SERVICE_PME) && pcie_pme_no_msi())

		goto legacy_irq;



	if ((mask & PCIE_PORT_SERVICE_HP) && pciehp_no_msi())

		goto legacy_irq;



	/* Try to use MSI-X or MSI if supported */

	if (pcie_port_enable_irq_vec(dev, irqs, mask) == 0)

		return 0;