From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org ([63.228.1.57]:46966 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752629Ab2GJPtv convert rfc822-to-8bit (ORCPT ); Tue, 10 Jul 2012 11:49:51 -0400 Subject: Re: [PATCH] PCI: Add pcie_irq=other to enable non MSI/INTx interrupt for port service driver Mime-Version: 1.0 (Apple Message framework v1278) Content-Type: text/plain; charset=us-ascii From: Kumar Gala In-Reply-To: <4FFC4AD0.3070201@freescale.com> Date: Tue, 10 Jul 2012 10:49:42 -0500 Cc: Liu Shengzhou-B36685 , "bhelgaas@google.com" , Wood Scott-B07421 , "linuxppc-dev@lists.ozlabs.org" , "linux-pci@vger.kernel.org" Message-Id: <009D8F85-2036-47C1-A19E-3E8D3EB8462F@kernel.crashing.org> References: <1341830970-12779-1-git-send-email-Shengzhou.Liu@freescale.com> <4FFB0927.7080406@freescale.com> <3F453DDFF675A64A89321A1F3528102176B4BF@039-SN1MPN1-003.039d.mgd.msft.net> <4FFC4AD0.3070201@freescale.com> To: Scott Wood Sender: linux-pci-owner@vger.kernel.org List-ID: 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@google.com; linux-pci@vger.kernel.org; linuxppc- >>> dev@lists.ozlabs.org >>> 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 >>>> --- >>>> 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 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 1FEFD2C0089 for ; Wed, 11 Jul 2012 01:49:49 +1000 (EST) Subject: Re: [PATCH] PCI: Add pcie_irq=other to enable non MSI/INTx interrupt for port service driver Mime-Version: 1.0 (Apple Message framework v1278) Content-Type: text/plain; charset=us-ascii From: Kumar Gala In-Reply-To: <4FFC4AD0.3070201@freescale.com> Date: Tue, 10 Jul 2012 10:49:42 -0500 Message-Id: <009D8F85-2036-47C1-A19E-3E8D3EB8462F@kernel.crashing.org> References: <1341830970-12779-1-git-send-email-Shengzhou.Liu@freescale.com> <4FFB0927.7080406@freescale.com> <3F453DDFF675A64A89321A1F3528102176B4BF@039-SN1MPN1-003.039d.mgd.msft.net> <4FFC4AD0.3070201@freescale.com> To: Scott Wood Cc: "bhelgaas@google.com" , Liu Shengzhou-B36685 , "linuxppc-dev@lists.ozlabs.org" , "linux-pci@vger.kernel.org" , Wood Scott-B07421 List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Jul 10, 2012, at 10:31 AM, Scott Wood wrote: > On 07/10/2012 01:13 AM, Liu Shengzhou-B36685 wrote: >>=20 >>=20 >>> -----Original Message----- >>> From: Wood Scott-B07421 >>> Sent: Tuesday, July 10, 2012 12:39 AM >>> To: Liu Shengzhou-B36685 >>> Cc: bhelgaas@google.com; linux-pci@vger.kernel.org; linuxppc- >>> dev@lists.ozlabs.org >>> Subject: Re: [PATCH] PCI: Add pcie_irq=3Dother to enable non = MSI/INTx interrupt >>> for port service driver >>>=20 >>> 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. >>>>=20 >>>> Signed-off-by: Shengzhou Liu >>>> --- >>>> Documentation/kernel-parameters.txt | 4 ++++ >>>> drivers/pci/pcie/portdrv_core.c | 19 +++++++++++++++++++ >>>> 2 files changed, 23 insertions(+), 0 deletions(-) >>>>=20 >>>> 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). >>>>=20 >>>> + pcie_irq=3D [PCIE] Native PCIe root port interrupt options: >>>> + other Try to use other interrupt when root port has >>>> + neither MSI/MSI-X nor INTx support. >>>=20 >>> Why does the user need to specify this? Shouldn't this be a matter = of >>> communication between kernel internals? >>>=20 >>=20 >> The "other interrupt" appears a non-standard interrupt way compared = to MSI/MSI-X and INTx in point of PCIe spec. >=20 > 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. >>=20 >> I'm glad to remove the specified kernel parameter if it would be = accepted upstream. >=20 > 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. >=20 > -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=