On Tue, Jun 12, 2018 at 2:42 PM Pingfan Liu <kernelfans@xxxxxxxxx> wrote: > > The Linux Device Driver Model allows a physical device to be handled > by only a single driver. But at present, both shpchp and portdrv_pci > claim PCI_CLASS_BRIDGE_PCI, and touch devices_kset. This causes a > few problems, one is the wrong shutdown seq of devices, owing to the > broken devices_kset. > > I hit this bug on a Power9 machine, when "kexec -e", and see a ata-disk > behind a bridge can not write back buffer in flight due to the former > shutdown of the bridge which clears the BusMaster bit. > > Note the device involved: > 0004:00:00.0 PCI bridge: IBM Device 04c1 (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 > NUMA node: 0 > Bus: primary=00, secondary=01, subordinate=12, sec-latency=0 > I/O behind bridge: 00000000-00000fff > Memory behind bridge: 80000000-ffefffff > Prefetchable memory behind bridge: 0006024000000000-0006027f7fffffff > 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] Power Management version 3 > Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0+,D1-,D2-,D3hot+,D3cold+) > Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME- > Capabilities: [48] Express (v2) Root Port (Slot-), MSI 00 > DevCap: MaxPayload 512 bytes, PhantFunc 0 > ExtTag- RBE+ > DevCtl: Report errors: Correctable- Non-Fatal- Fatal- Unsupported- > RlxdOrd- ExtTag- PhantFunc- AuxPwr- NoSnoop- > MaxPayload 256 bytes, MaxReadReq 128 bytes > DevSta: CorrErr- UncorrErr- FatalErr- UnsuppReq- AuxPwr- TransPend- > LnkCap: Port #0, Speed 8GT/s, Width x8, ASPM not supported, Exit Latency L0s <64ns, L1 <1us > ClockPM- Surprise- LLActRep+ BwNot+ ASPMOptComp- > LnkCtl: ASPM Disabled; RCB 128 bytes Disabled- CommClk- > ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt- > LnkSta: Speed 8GT/s, Width x4, 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+ > DevCtl2: Completion Timeout: 16ms to 55ms, TimeoutDis+, LTR-, OBFF Disabled ARIFwd+ > LnkCtl2: Target Link Speed: 8GT/s, EnterCompliance- SpeedDis- > Transmit Margin: Normal Operating Range, EnterModifiedCompliance- ComplianceSOS- > Compliance De-emphasis: -6dB > LnkSta2: Current De-emphasis Level: -3.5dB, EqualizationComplete+, EqualizationPhase1+ > EqualizationPhase2+, EqualizationPhase3+, LinkEqualizationRequest- > Capabilities: [100 v1] 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: [148 v1] #19 > > Signed-off-by: Pingfan Liu <kernelfans@xxxxxxxxx> > --- > drivers/pci/hotplug/shpchp_core.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/drivers/pci/hotplug/shpchp_core.c b/drivers/pci/hotplug/shpchp_core.c > index 1f0f969..2cd8e19 100644 > --- a/drivers/pci/hotplug/shpchp_core.c > +++ b/drivers/pci/hotplug/shpchp_core.c > @@ -287,6 +287,13 @@ static int shpc_probe(struct pci_dev *pdev, const struct pci_device_id *ent) > int rc; > struct controller *ctrl; > > + /* do not claim pcie port device */ > + if (pci_is_pcie(dev) && > + ((pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT) || > + (pci_pcie_type(dev) == PCI_EXP_TYPE_UPSTREAM) || > + (pci_pcie_type(dev) == PCI_EXP_TYPE_DOWNSTREAM))) > + return -ENODEV; > + Sorry, should s/dev/pdev/. I will try to loan a power9 to test it. NACK it, I will send out v2. Thanks, Pingfan > if (!is_shpc_capable(pdev)) > return -ENODEV; > > -- > 2.7.4 >
