On 9/11/18 12:32 AM, Johannes Berg wrote: > On Mon, 2018-09-10 at 19:17 -0700, Randy Dunlap wrote: >> Hi, >> >> Any ideas? > > Hmm. Is this new? I can't be sure. I've been having problems booting this laptop for a few weeks now but haven't tracked it down yet. >> 2018-09-10T18:47:54.532837-07:00 dragon kernel: [ 31.472371] kernel BUG at ../kernel/dma/swiotlb.c:521! > > nslots = ALIGN(size, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT; > [...] > BUG_ON(!nslots) > >> 2018-09-10T18:47:54.613655-07:00 dragon kernel: [ 31.490325] swiotlb_alloc+0x88/0x170 >> 2018-09-10T18:47:54.613656-07:00 dragon kernel: [ 31.490329] ? __kmalloc+0x1cc/0x200 >> 2018-09-10T18:47:54.613657-07:00 dragon kernel: [ 31.491652] iwl_pcie_txq_alloc+0x1d4/0x3b0 [iwlwifi] > > There are two calls to dma_alloc_coherent() here, should those even hit > swiotlb? The sizes of those should be > * 256 x 128 (32k) > * 32 x 256 (8k) [TFH, unlikely to be the case here] > * 256 x 256 (65k) [TFH] > * 32 x 64 (2k) > * 256 x 64 (16k) > > > IO_TLB_SHIFT is 11, so we get 2k alignment, so even the smallest size > (32*64) should result in nslots being 1? > > In fact, unless the driver passed *ZERO* as the size, this should never > happen (hence the BUG_ON), since ALIGN() would take care of rounding up > any smaller allocation here. > > Presumably you can reproduce this pretty easily (and I don't know what > specific model of NIC you have etc.), so perhaps you can do something > like this? The wireless NIC is Condor Peak: 04:00.0 Network controller: Intel Corporation Centrino Wireless-N 1000 [Condor Peak] Subsystem: Intel Corporation Centrino Wireless-N 1000 BGN 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 Interrupt: pin A routed to IRQ 31 Region 0: Memory at c2600000 (64-bit, non-prefetchable) [size=8K] Capabilities: [c8] 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: [d0] MSI: Enable+ Count=1/1 Maskable- 64bit+ Address: 00000000fee0800c Data: 4162 Capabilities: [e0] Express (v1) Endpoint, MSI 00 DevCap: MaxPayload 128 bytes, PhantFunc 0, Latency L0s <512ns, L1 unlimited ExtTag- AttnBtn- AttnInd- PwrInd- RBE+ FLReset+ SlotPowerLimit 0.000W DevCtl: Report errors: Correctable- Non-Fatal- Fatal- Unsupported- RlxdOrd+ ExtTag- PhantFunc- AuxPwr- NoSnoop+ FLReset- MaxPayload 128 bytes, MaxReadReq 128 bytes DevSta: CorrErr- UncorrErr- FatalErr- UnsuppReq- AuxPwr+ TransPend- LnkCap: Port #0, Speed 2.5GT/s, Width x1, ASPM L0s L1, Exit Latency L0s <128ns, L1 <32us ClockPM+ Surprise- LLActRep- BwNot- ASPMOptComp- LnkCtl: ASPM L0s L1 Enabled; 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- NonFatalErr- CEMsk: RxErr- BadTLP- BadDLLP- Rollover- Timeout- NonFatalErr+ AERCap: First Error Pointer: 00, ECRCGenCap- ECRCGenEn- ECRCChkCap- ECRCChkEn- MultHdrRecCap- MultHdrRecEn- TLPPfxPres- HdrLogCap- HeaderLog: 00000000 00000000 00000000 00000000 Capabilities: [140 v1] Device Serial Number 74-e5-0b-ff-ff-2d-dc-28 Kernel driver in use: iwlwifi Kernel modules: iwlwifi sigh. I can reproduce it without the patch: > https://p.sipsolutions.net/aa0dccd7a60fe176.txt but with that patch, it just hangs after about 25 seconds of booting (slow hard drive, not SSD). I'll try some other ways. -- ~Randy
