On Jul 10, 2012, at 10:31 AM, Scott Wood wrote: > On 07/10/2012 01:13 AM, Liu Shengzhou-B36685 wrote: >> >> >>> -----Original Message----- >>> From: Wood Scott-B07421 >>> Sent: Tuesday, July 10, 2012 12:39 AM >>> To: Liu Shengzhou-B36685 >>> Cc: bhelgaas@xxxxxxxxxx; linux-pci@xxxxxxxxxxxxxxx; linuxppc- >>> dev@xxxxxxxxxxxxxxxx >>> Subject: Re: [PATCH] PCI: Add pcie_irq=other to enable non MSI/INTx interrupt >>> for port service driver >>> >>> On 07/09/2012 05:49 AM, Shengzhou Liu wrote: >>>> On some platforms, in RC mode, root port has neither MSI/MSI-X nor >>>> INTx interrupt generated, which are available only in EP mode on those >>> platform. >>>> In this case, we try to use other interrupt if supported (i.e. there >>>> is the shared error interrupt on platform P1010, P3041, P4080, etc) to >>>> have AER, Hot-plug, etc, services to work. >>>> >>>> Signed-off-by: Shengzhou Liu <Shengzhou.Liu@xxxxxxxxxxxxx> >>>> --- >>>> Documentation/kernel-parameters.txt | 4 ++++ >>>> drivers/pci/pcie/portdrv_core.c | 19 +++++++++++++++++++ >>>> 2 files changed, 23 insertions(+), 0 deletions(-) >>>> >>>> diff --git a/Documentation/kernel-parameters.txt >>>> b/Documentation/kernel-parameters.txt >>>> index a92c5eb..af97c81 100644 >>>> --- a/Documentation/kernel-parameters.txt >>>> +++ b/Documentation/kernel-parameters.txt >>>> @@ -2218,6 +2218,10 @@ bytes respectively. Such letter suffixes can also be >>> entirely omitted. >>>> nomsi Do not use MSI for native PCIe PME signaling (this makes >>>> all PCIe root ports use INTx for all services). >>>> >>>> + pcie_irq= [PCIE] Native PCIe root port interrupt options: >>>> + other Try to use other interrupt when root port has >>>> + neither MSI/MSI-X nor INTx support. >>> >>> Why does the user need to specify this? Shouldn't this be a matter of >>> communication between kernel internals? >>> >> >> The "other interrupt" appears a non-standard interrupt way compared to MSI/MSI-X and INTx in point of PCIe spec. > > It still shouldn't be the user's responsibility to pass this in. I agree with Scott, this should be done in board code or as a PCI fixup, not as a command line arg. >> The intent of specifying this is to have an intervention and >> confirmation manually to avoid causing unexpected issue on some >> unknown platforms. >> >> I'm glad to remove the specified kernel parameter if it would be accepted upstream. > > Hopefully someone will comment if there is harm in doing this > unconditionally. If there is, then we should handle this via a quirk or > similar mechanism. > > -Scott If we need to do it via quirk, wondering if we can use the pci_dev_flags and set the flag in a quirk. - k-- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
