Hi Bjorn Helgaas, (C.C.ed to linux1394-devel@xxxxxxxxxxxxxxxxxxxxx) I have an objection to applying the change. I've been using the issued 1394 OHCI hardware in my development for recent years, while I have never faced the reported trouble. I think there are any misunderstanding or misjudge somwhow in the review process to apply it. Would I ask your precise advice to regenerate the reported issue in my local? This is my 1394 OHCI hardware. ``` $ sudo lspci -vvvnns 06:00.0 06:00.0 FireWire (IEEE 1394) [0c00]: LSI Corporation FW643 [TrueFire] PCIe 1394b Controller [11c1:5901] (rev 06) (prog-if 10 [OHCI]) Subsystem: LSI Corporation FW643 [TrueFire] PCIe 1394b Controller [11c1:5900] 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- Interrupt: pin A routed to IRQ 255 IOMMU group: 17 Region 0: Memory at fc700000 (64-bit, non-prefetchable) [disabled] [size=4K] Capabilities: [44] Power Management version 3 Flags: PMEClk- DSI- D1+ D2+ AuxCurrent=375mA PME(D0+,D1+,D2+,D3hot+,D3cold+) Status: D3 NoSoftRst- PME-Enable+ DSel=0 DScale=0 PME- Capabilities: [4c] MSI: Enable- Count=1/1 Maskable- 64bit+ Address: 0000000000000000 Data: 0000 Capabilities: [60] Express (v1) Endpoint, MSI 00 DevCap: MaxPayload 256 bytes, PhantFunc 0, Latency L0s <4us, L1 <64us ExtTag- AttnBtn- AttnInd- PwrInd- RBE+ FLReset- SlotPowerLimit 0W 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 2.5GT/s, Width x1, ASPM L0s L1, Exit Latency L0s <512ns, L1 <64us ClockPM+ Surprise- LLActRep- BwNot- ASPMOptComp- LnkCtl: ASPM Disabled; RCB 64 bytes, Disabled- CommClk+ ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt- LnkSta: Speed 2.5GT/s, Width x1 TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt- 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- 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 Capabilities: [140 v1] Virtual Channel Caps: LPEVC=0 RefClk=100ns PATEntryBits=1 Arb: Fixed- WRR32- WRR64- WRR128- Ctrl: ArbSelect=Fixed Status: InProgress- VC0: Caps: PATOffset=00 MaxTimeSlots=1 RejSnoopTrans- Arb: Fixed- WRR32- WRR64- WRR128- TWRR128- WRR256- Ctrl: Enable+ ID=0 ArbSelect=Fixed TC/VC=01 Status: NegoPending- InProgress- VC1: Caps: PATOffset=00 MaxTimeSlots=1 RejSnoopTrans- Arb: Fixed- WRR32- WRR64- WRR128- TWRR128- WRR256- Ctrl: Enable- ID=1 ArbSelect=Fixed TC/VC=00 Status: NegoPending- InProgress- Capabilities: [170 v1] Device Serial Number 12-34-56-10-12-30-00-86 Kernel driver in use: vfio-pci Kernel modules: firewire_ohci ``` I use it in the following environment at present: * Host system * AMD Ryzen 5 2400G * TUF GAMING X570-PLUS with BIOS 5003 (AGESA ComboV2PI 1.2.0.B) * SMT enabled * SVM enabled * IOMMU enabled * Secure boot disabled * Ubuntu 24.04 LTS amd64 * linux-image-6.8.0-11-generic (6.8.0-11.11) * default kernel cmdline * QEMU 8.2.1 (1:8.2.1+ds-1ubuntu1) * Libvert 10.0.0 (10.0.0-2ubuntu1) * Guest system * UEFI using OVMF * Seecure boot enabled * Ubuntu 24.04 LTS amd64 (the same as above) * default kernel cmdline > Using LSI / Agere FW643 with vfio-pci will exhaust all > pci_reset_fn_methods, the bus reset at the end causes a broken link > only recoverable by removing power > (power-off / suspend + rescan). > Prevent this bus reset. > With this change, the device can be assigned to VMs with VFIO. > Note that it will not be reset, resulting in leaking state between VMs > and host. > > Signed-off-by: Edmund Raile <edmund.raile@xxxxxxxxx> > > I sincerely thank you for your patience and explaining > the background of pci resets which I lacked. > The commit message and comment now describe it correctly. > The comment on leaking states was added. > > Usefulness: > > The LSI FW643 PCIe->FireWire 800 interface may be EOL but it is > the only one that does not use a PCIe->PCI bridge. > It is reliable and enables FireWire audio interfaces to be used > on modern machines. > > Virtualization allows for flexible access to professional audio > software. > > It has been used in at least the following Apple machines: > MacBookPro10,1 > MacBookPro9,2 > MacBookPro6,2 > MacBookPro5,1 > Macmini6,1 > Macmini3,1 > iMac12,2 > iMac9,1 > iMac8,1 > > Implementation: > > PCI_VENDOR_ID_ATT was reused as they are identical. > > drivers/pci/quirks.c | 13 +++++++++++++ > 1 file changed, 13 insertions(+) > > diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c > index d797df6e5f3e..e0e4ad9e6d50 100644 > --- a/drivers/pci/quirks.c > +++ b/drivers/pci/quirks.c > @@ -3765,6 +3765,19 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATHEROS, 0x003e, quirk_no_bus_reset); > */ > DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_CAVIUM, 0xa100, quirk_no_bus_reset); > > +/* > + * Using LSI / Agere FW643 with vfio-pci will exhaust all > + * pci_reset_fn_methods, the bus reset at the end causes a broken link > + * only recoverable by removing power > + * (power-off / suspend + rescan). > + * Prevent this bus reset. > + * With this change, the device can be assigned to VMs with VFIO. > + * Note that it will not be reset, resulting in leaking state between VMs > + * and host. > + */ > +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATT, 0x5900, quirk_no_bus_reset); > +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATT, 0x5901, quirk_no_bus_reset); > + > /* > * Some TI KeyStone C667X devices do not support bus/hot reset. The PCIESS > * automatically disables LTSSM when Secondary Bus Reset is received and Regards Takashi Sakamoto