Re: [PATCH V6 02/15] PCI/PME: Export pcie_pme_disable_msi() & pcie_pme_no_msi() APIs

From: Bjorn Helgaas
Date: Fri May 17 2019 - 14:57:58 EST

On Fri, May 17, 2019 at 11:23:36PM +0530, Vidya Sagar wrote:
> On 5/17/2019 6:54 PM, Bjorn Helgaas wrote:
> > Do you have "lspci -vvxxx" output for the root ports handy?
> >
> > If there's some clue in the standard config space that would tell us
> > that MSI works for some events but not others, we could make the PCI
> > core pay attention it. That would be the best solution because it
> > wouldn't require Tegra-specific code.
>
> Here is the output of 'lspci vvxxx' for one of Tegra194's root ports.

Thanks!

This port advertises both MSI and MSI-X, and neither one is enabled.
This particular port doesn't have a slot, so hotplug isn't applicable
to it.

But if I understand correctly, if MSI or MSI-X were enabled and the
port had a slot, the port would generate MSI/MSI-X hotplug interrupts.
But PME and AER events would still cause INTx interrupts (even with
MSI or MSI-X enabled).

Do I have that right? I just want to make sure that the reason for
PME being INTx is a permanent hardware choice and that it's not
related to MSI and MSI-X currently being disabled.

> 0005:00:00.0 PCI bridge: NVIDIA Corporation Device 1ad0 (rev a1) (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
> Interrupt: pin A routed to IRQ 50
> Bus: primary=00, secondary=01, subordinate=ff, sec-latency=0
> I/O behind bridge: None
> Memory behind bridge: 40000000-400fffff [size=1M]
> Prefetchable memory behind bridge: None
> Secondary status: 66MHz- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- <SERR- <PERR-
> BridgeCtl: Parity- SERR+ NoISA- VGA- VGA16- MAbort- >Reset- FastB2B-
> PriDiscTmr- SecDiscTmr- DiscTmrStat- DiscTmrSERREn-
> Capabilities: [40] Power Management version 3
> Flags: PMEClk- DSI- D1- D2- AuxCurrent=375mA PME(D0+,D1-,D2-,D3hot+,D3cold+)
> Status: D0 NoSoftRst+ PME-Enable- DSel=0 DScale=0 PME-
> Capabilities: [50] MSI: Enable- Count=1/1 Maskable+ 64bit+
> Address: 0000000000000000 Data: 0000
> Masking: 00000000 Pending: 00000000
> Capabilities: [70] Express (v2) Root Port (Slot-), MSI 00
> DevCap: MaxPayload 256 bytes, PhantFunc 0
> ExtTag- RBE+
> DevCtl: CorrErr+ NonFatalErr+ FatalErr+ UnsupReq+
> RlxdOrd+ ExtTag- PhantFunc- AuxPwr- NoSnoop+
> MaxPayload 128 bytes, MaxReadReq 512 bytes
> DevSta: CorrErr- NonFatalErr- FatalErr- UnsupReq- AuxPwr+ TransPend-
> LnkCap: Port #0, Speed 16GT/s, Width x8, ASPM L0s L1, Exit Latency L0s <1us, L1 <64us
> ClockPM- Surprise+ LLActRep+ BwNot+ ASPMOptComp+
> LnkCtl: ASPM Disabled; RCB 64 bytes Disabled- CommClk+
> ExtSynch- ClockPM- AutWidDis- BWInt+ AutBWInt-
> LnkSta: Speed 5GT/s (downgraded), Width x1 (downgraded)
> 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 ABCD, TimeoutDis+, LTR+, OBFF Not Supported ARIFwd-
> AtomicOpsCap: Routing- 32bit- 64bit- 128bitCAS-
> DevCtl2: Completion Timeout: 50us to 50ms, TimeoutDis-, LTR+, OBFF Disabled ARIFwd-
> AtomicOpsCtl: ReqEn- EgressBlck-
> LnkCtl2: Target Link Speed: 16GT/s, EnterCompliance- SpeedDis-
> Transmit Margin: Normal Operating Range, EnterModifiedCompliance- ComplianceSOS-
> Compliance De-emphasis: -6dB
> LnkSta2: Current De-emphasis Level: -6dB, EqualizationComplete-, EqualizationPhase1-
> EqualizationPhase2-, EqualizationPhase3-, LinkEqualizationRequest-
> Capabilities: [b0] MSI-X: Enable- Count=8 Masked-
> Vector table: BAR=2 offset=00000000
> PBA: BAR=2 offset=00010000
> Capabilities: [100 v2] 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- AdvNonFatalErr-
> CEMsk: RxErr- BadTLP- BadDLLP- Rollover- Timeout- AdvNonFatalErr+
> AERCap: First Error Pointer: 00, ECRCGenCap+ ECRCGenEn- ECRCChkCap+ ECRCChkEn-
> MultHdrRecCap+ MultHdrRecEn- TLPPfxPres- HdrLogCap-
> HeaderLog: 00000000 00000000 00000000 00000000
> RootCmd: CERptEn+ NFERptEn+ FERptEn+
> RootSta: CERcvd- MultCERcvd- UERcvd- MultUERcvd-
> FirstFatal- NonFatalMsg- FatalMsg- IntMsg 0
> ErrorSrc: ERR_COR: 0000 ERR_FATAL/NONFATAL: 0000
> Capabilities: [148 v1] Secondary PCI Express <?>
> Capabilities: [168 v1] Physical Layer 16.0 GT/s <?>
> Capabilities: [190 v1] Lane Margining at the Receiver <?>
> Capabilities: [1c0 v1] L1 PM Substates
> L1SubCap: PCI-PM_L1.2+ PCI-PM_L1.1+ ASPM_L1.2+ ASPM_L1.1+ L1_PM_Substates+
> PortCommonModeRestoreTime=60us PortTPowerOnTime=40us
> L1SubCtl1: PCI-PM_L1.2- PCI-PM_L1.1- ASPM_L1.2- ASPM_L1.1-
> T_CommonMode=10us LTR1.2_Threshold=0ns
> L1SubCtl2: T_PwrOn=10us
> Capabilities: [1d0 v1] Vendor Specific Information: ID=0002 Rev=4 Len=100 <?>
> Capabilities: [2d0 v1] Vendor Specific Information: ID=0001 Rev=1 Len=038 <?>
> Capabilities: [308 v1] Data Link Feature <?>
> Capabilities: [314 v1] Precision Time Measurement
> PTMCap: Requester:+ Responder:+ Root:+
> PTMClockGranularity: 16ns
> PTMControl: Enabled:- RootSelected:-
> PTMEffectiveGranularity: Unknown
> Capabilities: [320 v1] Vendor Specific Information: ID=0004 Rev=1 Len=054 <?>
> Kernel driver in use: pcieport
> 00: de 10 d0 1a 07 01 10 00 a1 00 04 06 00 00 01 00
> 10: 00 00 00 00 00 00 00 00 00 01 ff 00 f0 00 00 00
> 20: 00 40 00 40 f1 ff 01 00 00 00 00 00 00 00 00 00
> 30: 00 00 00 00 40 00 00 00 00 00 00 00 32 01 02 00
> 40: 01 50 c3 c9 08 00 00 00 00 00 00 00 00 00 00 00
> 50: 05 70 80 01 00 00 00 00 00 00 00 00 00 00 00 00
> 60: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> 70: 10 b0 42 00 01 80 00 00 1f 28 10 00 84 4c 7b 00
> 80: 40 04 12 f0 00 00 00 00 c0 03 40 00 18 00 01 00
> 90: 00 00 00 00 1f 0c 01 00 00 04 00 00 1e 00 80 01
> a0: 04 00 00 02 00 00 00 00 00 00 00 00 00 00 00 00
> b0: 11 00 07 00 02 00 00 00 02 00 01 00 00 00 00 00
> c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00