Re: [PATCH v5] Add pcie_hp=nomsi to disable MSI/MSI-X for pciehp driver

[Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>]

Reviewed-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>

Regards,
Kenji Kaneshige


(2012/02/15 2:55), MUNEDA Takahiro wrote:
> On Thu, 2 Feb 2012 11:09:22 -0500,
> MUNEDA Takahiro<muneda.takahiro@jp.fujitsu.com>  wrote:
> 
>> Not to use MSI/MSI-X for pciehp, add a kernel parameter, pcie_hp=nomsi.
>>
>> 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:
>>      <IRQ>    [<ffffffff810cec1d>] __report_bad_irq+0x3d/0xe0
>>      [<ffffffff810cee1c>] note_interrupt+0x15c/0x210
>>      [<ffffffff810cc485>] handle_irq_event_percpu+0xb5/0x210
>>      [<ffffffff810cc621>] handle_irq_event+0x41/0x70
>>      [<ffffffff810cf675>] handle_fasteoi_irq+0x55/0xc0
>>      [<ffffffff81015356>] handle_irq+0x46/0xb0
>>      [<ffffffff814fbe9d>] do_IRQ+0x5d/0xe0
>>      [<ffffffff814f146e>] common_interrupt+0x6e/0x6e
>>      [<ffffffff8106b040>] ? __do_softirq+0x60/0x210
>>      [<ffffffff8108aeb1>] ? hrtimer_interrupt+0x151/0x240
>>      [<ffffffff814fb5ec>] call_softirq+0x1c/0x30
>>      [<ffffffff810152d5>] do_softirq+0x65/0xa0
>>      [<ffffffff8106ae9d>] irq_exit+0xbd/0xe0
>>      [<ffffffff814fbf8e>] smp_apic_timer_interrupt+0x6e/0x99
>>      [<ffffffff814f9e5e>] apic_timer_interrupt+0x6e/0x80
>>      <EOI>    [<ffffffff814f0fb1>] ? _raw_spin_unlock_irqrestore+0x11/0x20
>>      [<ffffffff812629fc>] pci_bus_write_config_word+0x6c/0x80
>>      [<ffffffff81266fc2>] pci_intx+0x52/0xa0
>>      [<ffffffff8127de3d>] pci_intx_for_msi+0x1d/0x30
>>     [<ffffffff8127e4fb>] pci_msi_shutdown+0x7b/0x110
>>      [<ffffffff81269d34>] pci_device_shutdown+0x34/0x50
>>      [<ffffffff81326c4f>] device_shutdown+0x2f/0x140
>>      [<ffffffff8107b981>] kernel_restart_prepare+0x31/0x40
>>      [<ffffffff8107b9e6>] kernel_restart+0x16/0x60
>>      [<ffffffff8107bbfd>] sys_reboot+0x1ad/0x220
>>      [<ffffffff814f4b90>] ? do_page_fault+0x1e0/0x460
>>      [<ffffffff811942d0>] ? __sync_filesystem+0x90/0x90
>>      [<ffffffff8105c9aa>] ? __cond_resched+0x2a/0x40
>>      [<ffffffff814ef090>] ? _cond_resched+0x30/0x40
>>      [<ffffffff81169e17>] ? iterate_supers+0xb7/0xd0
>>      [<ffffffff814f9382>] system_call_fastpath+0x16/0x1b
>>     handlers:
>>     [<ffffffff8138a0f0>] usb_hcd_irq
>>     [<ffffffff8138a0f0>] usb_hcd_irq
>>     [<ffffffff8138a0f0>] 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.
> 
> ping.  Any comments?
> 
> Thanks,
> Takahiro
> 
>>
>> Signed-off-by: MUNEDA Takahiro<muneda.takahiro@jp.fujitsu.com>
>>
>> ---
>>    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(-)
>>
>> Index: linux-3.3-rc2/drivers/pci/pcie/portdrv.h
>> ===================================================================
>> --- linux-3.3-rc2.orig/drivers/pci/pcie/portdrv.h
>> +++ linux-3.3-rc2/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;
>>
>> Index: linux-3.3-rc2/drivers/pci/pcie/portdrv_core.c
>> ===================================================================
>> --- linux-3.3-rc2.orig/drivers/pci/pcie/portdrv_core.c
>> +++ linux-3.3-rc2/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_
>>    {
>>    	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;
>> Index: linux-3.3-rc2/Documentation/kernel-parameters.txt
>> ===================================================================
>> --- linux-3.3-rc2.orig/Documentation/kernel-parameters.txt
>> +++ linux-3.3-rc2/Documentation/kernel-parameters.txt
>> @@ -2118,6 +2118,10 @@ bytes respectively. Such letter suffixes
>>    		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
>> --
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>