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Message-ID: <51DF6912.5040305@hp.com>
Date: Fri, 12 Jul 2013 10:25:22 +0800
From: ZhenHua <zhen-hual@...com>
To: Bjorn Helgaas <bhelgaas@...gle.com>
CC: "linux-pci@...r.kernel.org" <linux-pci@...r.kernel.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 1/1] ia64/pci: set mmio decoding on for some host bridge
Hi Bjorn,
Thanks for your suggestions. I will try to find more information.
ZhenHua
On 07/11/2013 12:12 AM, Bjorn Helgaas wrote:
> On Wed, Jul 10, 2013 at 12:23 AM, ZhenHua <zhen-hual@...com> wrote:
>> Hi Bjorn,
>> On the system that this bug happens, an MCA event is generated while kernel
>> crashed:
>> Transaction Address: memory write to address 0x00000ae041428 (LMMIO -
>> SBL Blade 1 SFW DDR Memory)
>>
>> I guess the there is some module trying to visit the address 0x00000ae041428
>> right after this line is run:
>> pci_write_config_word(dev, PCI_COMMAND,
>> orig_cmd & ~(PCI_COMMAND_MEMORY | PCI_COMMAND_IO));
> Well, you need to figure out what is accessing 0x00000ae041428 and
> why. Presumably that address belongs to some device below the 40:01.0
> root port, and knowing which device that is would be a good clue, but
> you didn't include that in your lspci.
>
> I'm trying to give you hints about how *you* can figure out what's
> going on here. Obviously I don't have the system and I'm not
> proposing a change, so that's about all I can do.
>
>> The output of lspci -vvv is followed.
>> 40:01.0 PCI bridge: Intel Corporation 5520/5500/X58 I/O Hub PCI Express Root
>> Port 1 (rev 22) (prog-if 00 [Normal decode])
>> Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr+
>> Stepping- SERR+ FastB2B- DisINTx+
>> Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort-
>> <TAbort- <MAbort- >SERR- <PERR- INTx-
>> Latency: 0, Cache Line Size: 64 bytes
>> Bus: primary=40, secondary=41, subordinate=41, sec-latency=0
>> I/O behind bridge: 0000f000-00000fff
>> Memory behind bridge: ae000000-af8fffff
>> Prefetchable memory behind bridge: fffffffffff00000-00000000000fffff
>> Secondary status: 66MHz- FastB2B- ParErr- DEVSEL=fast >TAbort-
>> <TAbort- <MAbort- <SERR- <PERR-
>> BridgeCtl: Parity+ SERR+ NoISA- VGA- MAbort- >Reset- FastB2B-
>> PriDiscTmr- SecDiscTmr- DiscTmrStat- DiscTmrSERREn-
>> Capabilities: [40] Subsystem: Intel Corporation 5520/5500/X58 I/O
>> Hub PCI Express Root Port 1
>> Capabilities: [60] Message Signalled Interrupts: Mask+ 64bit-
>> Count=1/2 Enable+
>> Address: fee00000 Data: 4046
>> Masking: 00000002 Pending: 00000000
>> Capabilities: [90] Express (v2) Root Port (Slot-), MSI 00
>> DevCap: MaxPayload 256 bytes, PhantFunc 0, Latency L0s
>> <64ns, L1 <1us
>> ExtTag+ RBE+ FLReset-
>> DevCtl: Report errors: Correctable+ Non-Fatal+ Fatal+
>> Unsupported+
>> RlxdOrd- ExtTag- PhantFunc- AuxPwr- NoSnoop-
>> MaxPayload 128 bytes, MaxReadReq 128 bytes
>> DevSta: CorrErr- UncorrErr- FatalErr- UnsuppReq- AuxPwr-
>> TransPend-
>> LnkCap: Port #0, Speed 5GT/s, Width x2, ASPM L0s L1, Latency
>> L0 <512ns, L1 <64us
>> ClockPM- Suprise+ LLActRep+ BwNot+
>> LnkCtl: ASPM Disabled; RCB 64 bytes Disabled- Retrain-
>> CommClk-
>> ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt-
>> LnkSta: Speed 2.5GT/s, Width x1, TrErr- Train- SlotClk+
>> DLActive+ BWMgmt- ABWMgmt-
>> RootCtl: ErrCorrectable- ErrNon-Fatal- ErrFatal- PMEIntEna+
>> CRSVisible-
>> RootCap: CRSVisible-
>> RootSta: PME ReqID 0000, PMEStatus- PMEPending-
>> DevCap2: Completion Timeout: Range BCD, TimeoutDis+ ARIFwd+
>> DevCtl2: Completion Timeout: 260ms to 900ms, TimeoutDis-
>> ARIFwd-
>> LnkCtl2: Target Link Speed: 5GT/s, EnterCompliance-
>> SpeedDis-, Selectable De-emphasis: -3.5dB
>> Transmit Margin: Normal Operating Range,
>> EnterModifiedCompliance- ComplianceSOS-
>> Compliance De-emphasis: -6dB
>> LnkSta2: Current De-emphasis Level: -3.5dB
>> Capabilities: [e0] Power Management version 3
>> Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA
>> PME(D0+,D1-,D2-,D3hot+,D3cold+)
>> Status: D0 PME-Enable- DSel=0 DScale=0 PME-
>> Capabilities: [100] Advanced Error Reporting
>> UESta: DLP- SDES- TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt-
>> RxOF- MalfTLP- ECRC- UnsupReq- ACSViol-
>> UEMsk: DLP- SDES- TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt-
>> RxOF- MalfTLP- ECRC- UnsupReq- ACSViol-
>> UESvrt: DLP+ SDES+ TLP+ FCP+ CmpltTO- CmpltAbrt- UnxCmplt-
>> RxOF+ MalfTLP+ ECRC- UnsupReq+ ACSViol-
>> CESta: RxErr- BadTLP- BadDLLP- Rollover- Timeout-
>> NonFatalErr-
>> CEMsk: RxErr- BadTLP- BadDLLP- Rollover- Timeout-
>> NonFatalErr+
>> AERCap: First Error Pointer: 00, GenCap- CGenEn- ChkCap-
>> ChkEn-
>> Capabilities: [150] Access Control Services
>> ACSCap: SrcValid+ TransBlk+ ReqRedir+ CmpltRedir+
>> UpstreamFwd+ EgressCtrl- DirectTrans-
>> ACSCtl: SrcValid- TransBlk- ReqRedir- CmpltRedir-
>> UpstreamFwd- EgressCtrl- DirectTrans-
>> Capabilities: [160] Vendor Specific Information <?>
>> Kernel driver in use: pcieport
>> Kernel modules: shpchp
>>
>>
>>
>> On 07/10/2013 12:49 AM, Bjorn Helgaas wrote:
>>
>> On Mon, Jul 8, 2013 at 11:42 PM, Li, Zhen-Hua <zhen-hual@...com> wrote:
>>
>> On some IA64 platforms with intel PCI bridge, for example, HP BL890c i2
>> with Intel Corporation 5520/5500/X58 I/O Hub PCI Express Root Port,
>> when kernel tries to disable the mmio decoding on the PCI bridge devices,
>> kernel may crash.
>>
>> And in the comment of function quirk_mmio_always_on, it also says:
>> "But doing so (disable the mmio decoding) may cause problems on host bridge
>> and perhaps other key system devices"
>>
>> So, for this PCI bridge, dev->mmio_always_on bit should be set to 1.
>>
>> To avoid affecting the use of quirk_mmio_always_on, a new function is
>> created.
>>
>> Signed-off-by: Li, Zhen-Hua <zhen-hual@...com>
>> ---
>> drivers/pci/quirks.c | 17 +++++++++++++++++
>> include/linux/pci_ids.h | 1 +
>> 2 files changed, 18 insertions(+)
>>
>> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
>> index e85d230..665af3e 100644
>> --- a/drivers/pci/quirks.c
>> +++ b/drivers/pci/quirks.c
>> @@ -44,6 +44,23 @@ static void quirk_mmio_always_on(struct pci_dev *dev)
>> DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_ANY_ID, PCI_ANY_ID,
>> PCI_CLASS_BRIDGE_HOST, 8,
>> quirk_mmio_always_on);
>>
>> +#ifdef CONFIG_IA64
>> +/*
>> + * On some IA64 platforms, for some intel PCI bridge devices, for example,
>> + * the Intel Corporation 5520/5500/X58 I/O Hub PCI Express Root Port,
>> + * disable the mmio decoding on this device may cause system crash.
>> + * So dev->mmio_always_on bit should be set to 1.
>> + */
>> +static void quirk_mmio_on_intel_pcibridge(struct pci_dev *dev)
>> +{
>> + dev->mmio_always_on = 1;
>> +}
>> +DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_INTEL,
>> + PCI_DEVICE_ID_INTEL_5520_5550_X58,
>> + PCI_CLASS_BRIDGE_PCI,
>> + 8, quirk_mmio_on_intel_pcibridge);
>> +#endif
>> +
>> /* The Mellanox Tavor device gives false positive parity errors
>> * Mark this device with a broken_parity_status, to allow
>> * PCI scanning code to "skip" this now blacklisted device.
>> diff --git a/include/linux/pci_ids.h b/include/linux/pci_ids.h
>> index 3bed2e8..d8c60b7 100644
>> --- a/include/linux/pci_ids.h
>> +++ b/include/linux/pci_ids.h
>> @@ -2742,6 +2742,7 @@
>> #define PCI_DEVICE_ID_INTEL_LYNNFIELD_MC_CH2_RANK_REV2 0x2db2
>> #define PCI_DEVICE_ID_INTEL_LYNNFIELD_MC_CH2_TC_REV2 0x2db3
>> #define PCI_DEVICE_ID_INTEL_82855PM_HB 0x3340
>> +#define PCI_DEVICE_ID_INTEL_5520_5550_X58 0x3408
>> #define PCI_DEVICE_ID_INTEL_IOAT_TBG4 0x3429
>> #define PCI_DEVICE_ID_INTEL_IOAT_TBG5 0x342a
>> #define PCI_DEVICE_ID_INTEL_IOAT_TBG6 0x342b
>> --
>> 1.7.10.4
>>
>> You need to figure out what the problem is, not just avoid it. It's
>> very unlikely that the problem is something unique to ia64. In fact,
>> I think it's very doubtful that the problem is even something unique
>> to the 5520 root ports. My guess is there's something special about
>> the system you're testing.
>>
>> Evidently you have traffic going to a device behind the root port at
>> the same time as we're trying to read the root port's BARs. Linux
>> should not generate traffic like that while we're enumerating the root
>> port. Does the problem happen on a root port with an iLO behind it?
>> Can you collect "lspci -vvv" output and identify the root port where
>> the problem occurs?
>>
>> Bjorn
>>
>>
--
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