> That isn't a limit, just a reporting clause - the real check is this > line a little above: > > if (unlikely(dev && !dma_capable(dev, dma_addr, size))) { > > which is purely based on the dma mask. So for some reason we must > be in 32-bit only mode for the dma-mask, and not actually enabling > swiotlb. And thinking more about it the latter is what is really odd, > we should always enable swiotlb for systems with 4GB memory. I'll > defintivetly wait for your dmesg! Christoph, here is the dmesg output. It does not successfully boot. [ 16.527021] aic7xxx: large SCBS not supported [ 21.984104] scsi host0: Adaptec AIC7XXX EISA/VLB/PCI SCSI HBA DRIVER, Rev 7.0 [ 21.984104] <Adaptec aic7892 Ultra160 SCSI adapter> [ 21.984104] aic7892: Ultra160 Wide Channel A, SCSI Id=7, 32/253 SCBs [ 21.984104] [ 22.012511] scsi 0:0:0:0: Direct-Access SEAGATE ST373454LC D403 PQ: 0 ANSI: 3 [ 22.020995] scsi0:A:0:0: [ 22.020997] Tagged Queuing enabled. Depth 32 [ 22.028503] scsi target0:0:0: Beginning Domain Validation [ 22.037780] scsi target0:0:0: wide asynchronous [ 22.045276] scsi target0:0:0: FAST-80 WIDE SCSI 160.0 MB/s DT (12.5 ns, offset 63) [ 22.056417] scsi 0:0:0:0: Power-on or device reset occurred [ 22.065532] scsi target0:0:0: Ending Domain Validation [ 22.104034] scsi 0:0:1:0: Direct-Access FUJITSU MAW3147NC 0104 PQ: 0 ANSI: 3 [ 22.112535] scsi0:A:1:0: [ 22.112538] Tagged Queuing enabled. Depth 32 [ 22.120056] scsi target0:0:1: Beginning Domain Validation [ 22.129058] scsi target0:0:1: wide asynchronous [ 22.136422] scsi target0:0:1: FAST-80 WIDE SCSI 160.0 MB/s DT (12.5 ns, offset 127) [ 22.152111] scsi 0:0:1:0: Power-on or device reset occurred [ 22.161065] scsi target0:0:1: Ending Domain Validation [ 22.188449] scsi 0:0:2:0: Direct-Access IBM IC35L073UCDY10-0 S27N PQ: 0 ANSI: 3 [ 22.196952] scsi0:A:2:0: [ 22.196955] Tagged Queuing enabled. Depth 32 [ 22.204460] scsi target0:0:2: Beginning Domain Validation [ 22.222059] random: fast init done [ 22.225725] scsi target0:0:2: wide asynchronous [ 22.231731] scsi target0:0:2: FAST-20 WIDE SCSI 40.0 MB/s ST (50 ns, offset 8) [ 22.240024] scsi target0:0:2: Domain Validation skipping write tests [ 22.246600] scsi target0:0:2: Ending Domain Validation [ 22.284567] scsi 0:0:3:0: Direct-Access IBM IC35L073UCDY10-0 S27N PQ: 0 ANSI: 3 [ 22.293069] scsi0:A:3:0: [ 22.293072] Tagged Queuing enabled. Depth 32 [ 22.300583] scsi target0:0:3: Beginning Domain Validation [ 22.328612] scsi target0:0:3: wide asynchronous [ 22.334718] scsi target0:0:3: FAST-20 WIDE SCSI 40.0 MB/s ST (50 ns, offset 8) [ 22.343006] scsi target0:0:3: Domain Validation skipping write tests [ 22.349589] scsi target0:0:3: Ending Domain Validation [ 22.901684] scsi 0:0:6:0: Processor PE/PV 1x5 SCSI BP 1.1 PQ: 0 ANSI: 2 [ 22.910273] scsi target0:0:6: Beginning Domain Validation [ 22.939101] scsi target0:0:6: Ending Domain Validation [ 25.096168] sd 0:0:0:0: [sda] 143374650 512-byte logical blocks: (73.4 GB/68.4 GiB) [ 25.096225] sd 0:0:1:0: [sdb] 287277984 512-byte logical blocks: (147 GB/137 GiB) [ 25.107747] sd 0:0:2:0: Power-on or device reset occurred [ 25.139537] sd 0:0:3:0: Power-on or device reset occurred [ 25.145255] sd 0:0:0:0: [sda] Write Protect is off [ 25.145278] sd 0:0:1:0: [sdb] Write Protect is off [ 25.145643] scsi host1: pata_serverworks [ 25.177180] sd 0:0:2:0: [sdc] 143374805 512-byte logical blocks: (73.4 GB/68.4 GiB) [ 25.177240] sd 0:0:3:0: [sdd] 143374805 512-byte logical blocks: (73.4 GB/68.4 GiB) [ 25.178429] sd 0:0:1:0: [sdb] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA [ 25.189353] sd 0:0:0:0: [sda] Write cache: disabled, read cache: enabled, supports DPO and FUA [ 25.200252] scsi host2: pata_serverworks [ 25.202942] sd 0:0:3:0: [sdd] Write Protect is off [ 25.202953] sd 0:0:2:0: [sdc] Write Protect is off [ 25.213855] ata1: PATA max UDMA/100 cmd 0x1f0 ctl 0x3f6 bmdma 0x8b0 irq 14 [ 25.247030] sd 0:0:2:0: [sdc] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA [ 25.247037] ata2: PATA max UDMA/100 cmd 0x170 ctl 0x376 bmdma 0x8b8 irq 15 [ 25.278937] sd 0:0:3:0: [sdd] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA [ 25.300661] sdb: sdb1 [ 25.406317] sda: sda1 sda2 [ 25.409465] sdc: sdc1 [ 25.474427] sd 0:0:1:0: [sdb] Attached SCSI disk [ 25.475141] sdd: sdd1 [ 25.486165] sd 0:0:2:0: [sdc] Attached SCSI disk [ 25.529044] sd 0:0:0:0: [sda] Attached SCSI disk [ 25.530061] sd 0:0:3:0: [sdd] Attached SCSI disk [ 25.537753] scsi 1:0:0:0: CD-ROM HL-DT-ST RW/DVD GCC-4243N A102 PQ: 0 ANSI: 5 [ 25.963649] EXT4-fs (sda2): mounting ext3 file system using the ext4 subsystem [ 26.206768] EXT4-fs (sda2): mounted filesystem with ordered data mode. Opts: (null) [ 26.214856] VFS: Mounted root (ext3 filesystem) readonly on device 8:2. [ 26.274864] devtmpfs: mounted [ 26.278548] Freeing unused kernel image memory: 500K [ 26.283885] Write protecting the kernel text: 3540k [ 26.289142] Write protecting the kernel read-only data: 1976k [ 27.895223] random: crng init done [ 28.369523] aic7xxx 0000:00:03.0: dma_direct_map_sg: overflow 0x00000003ff800000+65536 of device mask ffffffff [ 28.424016] aic7xxx 0000:00:03.0: dma_direct_map_sg: overflow 0x00000003ff800000+65536 of device mask ffffffff [ 28.480015] aic7xxx 0000:00:03.0: dma_direct_map_sg: overflow 0x00000003ff800000+65536 of device mask ffffffff [ 28.536015] aic7xxx 0000:00:03.0: dma_direct_map_sg: overflow 0x00000003ff800000+65536 of device mask ffffffff - Matthew