Hi Tejun, Thanks very much for your patch - I gave it a spin (against Debian's 2.6.38 kernel) - it's apparently working better than before, but still a bit wonky... This is what happens when I hot-plugging the 3726 (with two drives attached to it) into a SiI3132... 399.038172] ata2: exception Emask 0x10 SAct 0x0 SErr 0x0 action 0xe frozen 399.038296] ata2: irq_stat 0x00b40090, PHY RDY changed 399.038402] ata2: hard resetting link 401.235936] ata2: SATA link up 3.0 Gbps (SStatus 123 SControl 0) 401.236557] ata2.15: Port Multiplier 1.1, 0x1095:0x3726 r23, 6 ports, feat 0x1/0x9 401.236904] ata2.00: hard resetting link 401.556327] ata2.00: SATA link up 1.5 Gbps (SStatus 113 SControl 320) 401.556471] ata2.01: hard resetting link 401.876223] ata2.01: SATA link down (SStatus 0 SControl 320) 401.876440] ata2.02: hard resetting link 402.196093] ata2.02: SATA link down (SStatus 0 SControl 320) 402.196304] ata2.03: hard resetting link 402.516010] ata2.03: SATA link up 3.0 Gbps (SStatus 123 SControl 300) 402.516204] ata2.04: hard resetting link 402.835901] ata2.04: SATA link down (SStatus 0 SControl 320) 403.147472] ata2.05: no reset method available, skipping reset 403.147925] ata2.05: SATA link up 1.5 Gbps (SStatus 113 SControl 300) 403.148773] ata2.00: ATA-7: Maxtor 6Y120M0, YAR51BW0, max UDMA/133 403.148945] ata2.00: 240121728 sectors, multi 0: LBA 403.150032] ata2.00: configured for UDMA/100 403.151113] ata2.03: ATA-7: Hitachi HUA721010KLA330, GKAOAB0A, max UDMA/133 403.151302] ata2.03: 1953525168 sectors, multi 0: LBA48 NCQ (depth 31/32) 403.152568] ata2.03: configured for UDMA/100 403.152721] ata2: EH complete 403.152867] scsi 1:0:0:0: Direct-Access ATA Maxtor 6Y120M0 YAR5 PQ: 0 ANSI: 5 403.153349] sd 1:0:0:0: [sdb] 240121728 512-byte logical blocks: (122 GB/114 GiB) 403.153439] sd 1:0:0:0: [sdb] Write Protect is off 403.153459] sd 1:0:0:0: [sdb] Mode Sense: 00 3a 00 00 403.153505] sd 1:0:0:0: [sdb] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA 403.154034] scsi 1:3:0:0: Direct-Access ATA Hitachi HUA72101 GKAO PQ: 0 ANSI: 5 403.154481] sd 1:3:0:0: [sdc] 1953525168 512-byte logical blocks: (1.00 TB/931 GiB) 403.154546] sd 1:3:0:0: [sdc] Write Protect is off 403.154548] sd 1:3:0:0: [sdc] Mode Sense: 00 3a 00 00 403.154572] sd 1:3:0:0: [sdc] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA 403.162661] sdb: sdb1 403.163293] sd 1:0:0:0: [sdb] Attached SCSI disk 403.168597] sdc: sdc1 sdc2 < sdc5 > 403.169009] sd 1:3:0:0: [sdc] Attached SCSI disk ... reads from those drives then seem to work fine. Unplugging from the 3132 (and waiting for things to settle), then plugging into the 88SE9123 gives the following... 541.610033] ata14: exception Emask 0x10 SAct 0x0 SErr 0x4050000 action 0xe frozen 541.610166] ata14: irq_stat 0x80400040, connection status changed 541.610277] ata14: SError: { PHYRdyChg CommWake DevExch } 541.610391] ata14: hard resetting link 543.288743] ata14: SATA link up 3.0 Gbps (SStatus 123 SControl 370) 543.289086] ata14.15: Port Multiplier 1.1, 0x1095:0x3726 r23, 6 ports, feat 0x1/0x9 543.289220] ahci 0000:01:00.0: FBS is enabled. 543.289418] ata14.00: hard resetting link 543.608852] ata14.00: SATA link up 1.5 Gbps (SStatus 113 SControl 320) 543.609031] ata14.01: hard resetting link 543.928756] ata14.01: SATA link down (SStatus 0 SControl 320) 543.928943] ata14.02: hard resetting link 544.248663] ata14.02: SATA link down (SStatus 0 SControl 320) 544.248856] ata14.03: hard resetting link 544.568553] ata14.03: SATA link up 3.0 Gbps (SStatus 123 SControl 300) 544.880294] ata14.05: no reset method available, skipping reset 544.880594] ata14.05: SATA link up 1.5 Gbps (SStatus 113 SControl 300) 544.881914] ata14.03: ATA-7: Hitachi HUA721010KLA330, GKAOAB0A, max UDMA/133 544.882099] ata14.03: 1953525168 sectors, multi 0: LBA48 NCQ (depth 31/32), AA 544.883774] ata14.03: configured for UDMA/133 544.883987] ata14: EH complete 544.884213] scsi 13:3:0:0: Direct-Access ATA Hitachi HUA72101 GKAO PQ: 0 ANSI: 5 544.884750] sd 13:3:0:0: [sdb] 1953525168 512-byte logical blocks: (1.00 TB/931 GiB) 544.884879] sd 13:3:0:0: [sdb] Write Protect is off 544.884892] sd 13:3:0:0: [sdb] Mode Sense: 00 3a 00 00 544.884957] sd 13:3:0:0: [sdb] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA 544.897087] sdb: sdb1 sdb2 < sdb5 > 544.897519] sd 13:3:0:0: [sdb] Attached SCSI disk ... so definitely some progress, but the Maxtor drive on PMP port zero hasn't been found... I then hot-un-plugged the Maxtor from the pmp and got this lot: 709.515101] ata14.15: PMP product ID mismatch 709.515256] ata14.15: hard resetting link 715.043716] ata14.15: SATA link up 3.0 Gbps (SStatus 123 SControl 370) 715.044020] ata14.15: Port Multiplier vendor mismatch '0x1095' != '0x0' 715.044191] ata14.15: PMP revalidation failed (errno=-19) 715.044352] ata14.15: limiting SATA link speed to 1.5 Gbps 720.042049] ata14.15: hard resetting link 725.572222] ata14.15: SATA link up 1.5 Gbps (SStatus 113 SControl 310) 725.572595] ata14.15: Port Multiplier vendor mismatch '0x1095' != '0x0' 725.572767] ata14.15: PMP revalidation failed (errno=-19) 730.570649] ata14.15: hard resetting link 736.100725] ata14.15: SATA link up 1.5 Gbps (SStatus 113 SControl 310) 736.101093] ata14.15: Port Multiplier vendor mismatch '0x1095' != '0x0' 736.101259] ata14.15: PMP revalidation failed (errno=-19) 736.101417] ata14.15: failed to recover PMP after 5 tries, giving up 736.101578] ata14.15: Port Multiplier detaching 736.101732] ata14.03: disabled 736.101874] ata14.00: disabled 741.099118] ata14: hard resetting link 746.629228] ata14: SATA link up 3.0 Gbps (SStatus 123 SControl 370) 746.629636] ata14.15: Port Multiplier 1.1, 0x1095:0x3726 r23, 6 ports, feat 0x1/0x9 746.629880] ahci 0000:01:00.0: FBS is enabled. 746.630139] ata14.00: hard resetting link 746.949339] ata14.00: SATA link down (SStatus 0 SControl 310) 746.949534] ata14.01: hard resetting link 747.269258] ata14.01: SATA link down (SStatus 0 SControl 320) 747.269448] ata14.02: hard resetting link 747.589167] ata14.02: SATA link down (SStatus 0 SControl 320) 747.589359] ata14.03: hard resetting link 747.909043] ata14.03: SATA link up 3.0 Gbps (SStatus 123 SControl 300) 747.909230] ata14.04: hard resetting link 748.228933] ata14.04: SATA link down (SStatus 0 SControl 320) 748.540699] ata14.05: no reset method available, skipping reset 748.541014] ata14.05: SATA link up 1.5 Gbps (SStatus 113 SControl 300) 748.542361] ata14.03: ATA-7: Hitachi HUA721010KLA330, GKAOAB0A, max UDMA/133 748.542549] ata14.03: 1953525168 sectors, multi 0: LBA48 NCQ (depth 31/32), AA 748.544247] ata14.03: configured for UDMA/133 748.544445] ata14: EH complete 748.544610] ata14.03: detaching (SCSI 13:3:0:0) 748.556691] sd 13:3:0:0: [sdb] Synchronizing SCSI cache 748.556960] sd 13:3:0:0: [sdb] Stopping disk 749.009984] scsi 13:3:0:0: Direct-Access ATA Hitachi HUA72101 GKAO PQ: 0 ANSI: 5 749.010373] sd 13:3:0:0: [sdb] 1953525168 512-byte logical blocks: (1.00 TB/931 GiB) 749.025616] sd 13:3:0:0: [sdb] Write Protect is off 749.025619] sd 13:3:0:0: [sdb] Mode Sense: 00 3a 00 00 749.025641] sd 13:3:0:0: [sdb] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA 751.208927] sdb: sdb1 sdb2 < sdb5 > 751.209352] sd 13:3:0:0: [sdb] Attached SCSI disk Plugging the Maxtor back in then gave: 813.046630] ata14.15: PMP product ID mismatch 813.046787] ata14.15: hard resetting link 814.766608] ata14.15: SATA link up 3.0 Gbps (SStatus 123 SControl 370) 814.766916] ata14.15: Port Multiplier vendor mismatch '0x1095' != '0x0' 814.767080] ata14.15: PMP revalidation failed (errno=-19) 814.767241] ata14.15: limiting SATA link speed to 1.5 Gbps 819.764939] ata14.15: hard resetting link 821.488377] ata14.15: SATA link up 1.5 Gbps (SStatus 113 SControl 310) 821.488766] ata14.15: Port Multiplier vendor mismatch '0x1095' != '0x0' 821.488932] ata14.15: PMP revalidation failed (errno=-19) 826.486679] ata14.15: hard resetting link 828.210145] ata14.15: SATA link up 1.5 Gbps (SStatus 113 SControl 310) 828.210520] ata14.15: Port Multiplier vendor mismatch '0x1095' != '0x0' 828.210681] ata14.15: PMP revalidation failed (errno=-19) 828.210832] ata14.15: failed to recover PMP after 5 tries, giving up 828.210990] ata14.15: Port Multiplier detaching 828.211136] ata14.03: disabled 828.211274] ata14.00: disabled 833.208478] ata14: hard resetting link 834.931910] ata14: SATA link up 3.0 Gbps (SStatus 123 SControl 370) 834.932300] ata14.15: Port Multiplier 1.1, 0x1095:0x3726 r23, 6 ports, feat 0x1/0x9 834.932550] ahci 0000:01:00.0: FBS is enabled. 834.932810] ata14.00: hard resetting link 835.252010] ata14.00: SATA link up 1.5 Gbps (SStatus 113 SControl 310) 835.252200] ata14.01: hard resetting link 835.571932] ata14.01: SATA link down (SStatus 0 SControl 320) 835.572139] ata14.02: hard resetting link 835.891849] ata14.02: SATA link down (SStatus 0 SControl 320) 835.892045] ata14.03: hard resetting link 836.211721] ata14.03: SATA link up 3.0 Gbps (SStatus 123 SControl 300) 836.211903] ata14.04: hard resetting link 836.531597] ata14.04: SATA link down (SStatus 0 SControl 320) 836.843382] ata14.05: no reset method available, skipping reset 836.843720] ata14.05: SATA link up 1.5 Gbps (SStatus 113 SControl 300) 836.844502] ata14.00: ATA-7: Maxtor 6Y120M0, YAR51BW0, max UDMA/133 836.844674] ata14.00: 240121728 sectors, multi 0: LBA 836.845674] ata14.00: configured for UDMA/133 836.847053] ata14.03: ATA-7: Hitachi HUA721010KLA330, GKAOAB0A, max UDMA/133 836.847228] ata14.03: 1953525168 sectors, multi 0: LBA48 NCQ (depth 31/32), AA 836.848736] ata14.03: configured for UDMA/133 836.848913] ata14: EH complete 836.848922] ata14.03: detaching (SCSI 13:3:0:0) 836.871374] sd 13:3:0:0: [sdb] Synchronizing SCSI cache 836.871703] sd 13:3:0:0: [sdb] Stopping disk 837.322901] scsi 13:0:0:0: Direct-Access ATA Maxtor 6Y120M0 YAR5 PQ: 0 ANSI: 5 837.323334] sd 13:0:0:0: [sdb] 240121728 512-byte logical blocks: (122 GB/114 GiB) 837.323392] sd 13:0:0:0: [sdb] Write Protect is off 837.323395] sd 13:0:0:0: [sdb] Mode Sense: 00 3a 00 00 837.323421] sd 13:0:0:0: [sdb] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA 837.323670] scsi 13:3:0:0: Direct-Access ATA Hitachi HUA72101 GKAO PQ: 0 ANSI: 5 837.324358] sd 13:3:0:0: [sdc] 1953525168 512-byte logical blocks: (1.00 TB/931 GiB) 837.324628] sd 13:3:0:0: [sdc] Write Protect is off 837.324787] sd 13:3:0:0: [sdc] Mode Sense: 00 3a 00 00 837.324815] sd 13:3:0:0: [sdc] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA 837.327022] sdb: sdb1 837.327376] sd 13:0:0:0: [sdb] Attached SCSI disk 839.487216] sdc: sdc1 sdc2 < sdc5 > 839.487664] sd 13:3:0:0: [sdc] Attached SCSI disk .... and reading from each disk individually works, but reading from both at the same time doesn't (I/Os time-out, and then the whole lot gets reset). 839.487664] sd 13:3:0:0: [sdc] Attached SCSI disk 928.712783] ata14.00: failed to read SCR 1 (Emask=0x40) 928.713010] ata14.01: failed to read SCR 1 (Emask=0x40) 928.713167] ata14.02: failed to read SCR 1 (Emask=0x40) 928.713320] ata14.03: failed to read SCR 1 (Emask=0x40) 928.713474] ata14.04: failed to read SCR 1 (Emask=0x40) 928.713630] ata14.05: failed to read SCR 1 (Emask=0x40) 928.713787] ata14.15: exception Emask 0x4 SAct 0x0 SErr 0x0 action 0x6 frozen 928.713957] ata14.00: exception Emask 0x100 SAct 0x0 SErr 0x0 action 0x6 frozen 928.714178] ata14.01: exception Emask 0x100 SAct 0x0 SErr 0x0 action 0x6 frozen 928.714399] ata14.02: exception Emask 0x100 SAct 0x0 SErr 0x0 action 0x6 frozen 928.714620] ata14.03: exception Emask 0x100 SAct 0x3 SErr 0x0 action 0x6 frozen 928.714841] ata14.03: failed command: READ FPDMA QUEUED 928.714999] ata14.03: cmd 60/00:00:00:02:00/01:00:00:00:00/40 tag 0 ncq 131072 in 928.715000] res 40/00:01:00:00:00/00:00:00:00:00/00 Emask 0x4 (timeout) 928.715440] ata14.03: status: { DRDY } 928.715583] ata14.03: failed command: READ FPDMA QUEUED 928.715738] ata14.03: cmd 60/00:08:00:03:00/01:00:00:00:00/40 tag 1 ncq 131072 in 928.715739] res 40/00:00:00:00:00/00:00:00:00:00/00 Emask 0x4 (timeout) 928.716179] ata14.03: status: { DRDY } 928.716329] ata14.04: exception Emask 0x100 SAct 0x0 SErr 0x0 action 0x6 frozen 928.716552] ata14.05: exception Emask 0x100 SAct 0x0 SErr 0x0 action 0x6 frozen 928.716785] ata14.15: hard resetting link 930.440201] ata14.15: SATA link up 3.0 Gbps (SStatus 123 SControl 370) 930.440531] ata14.15: Port Multiplier vendor mismatch '0x1095' != '0x0' 930.440702] ata14.15: PMP revalidation failed (errno=-19) 935.438490] ata14.15: hard resetting link 937.161975] ata14.15: SATA link up 3.0 Gbps (SStatus 123 SControl 370) 937.162311] ata14.15: Port Multiplier vendor mismatch '0x1095' != '0x0' 937.162474] ata14.15: PMP revalidation failed (errno=-19) 937.162629] ata14.15: limiting SATA link speed to 1.5 Gbps 942.160272] ata14.15: hard resetting link 943.883736] ata14.15: SATA link up 1.5 Gbps (SStatus 113 SControl 310) 943.884114] ata14.15: Port Multiplier vendor mismatch '0x1095' != '0x0' 943.884297] ata14.15: PMP revalidation failed (errno=-19) 943.884457] ata14.15: failed to recover PMP after 5 tries, giving up 943.884623] ata14.15: Port Multiplier detaching 943.884778] ata14.00: disabled 943.884920] ata14.03: disabled 943.885063] ata14.00: disabled 948.882087] ata14: hard resetting link 950.605510] ata14: SATA link up 3.0 Gbps (SStatus 123 SControl 370) 950.605902] ata14.15: Port Multiplier 1.1, 0x1095:0x3726 r23, 6 ports, feat 0x1/0x9 950.606143] ahci 0000:01:00.0: FBS is enabled. 950.606387] ata14.00: hard resetting link 950.925629] ata14.00: SATA link up 1.5 Gbps (SStatus 113 SControl 310) 950.925807] ata14.01: hard resetting link 951.245532] ata14.01: SATA link down (SStatus 0 SControl 320) 951.245728] ata14.02: hard resetting link 951.565428] ata14.02: SATA link down (SStatus 0 SControl 320) 951.565625] ata14.03: hard resetting link 951.885272] ata14.03: SATA link up 3.0 Gbps (SStatus 123 SControl 300) 951.885449] ata14.04: hard resetting link 952.205216] ata14.04: SATA link down (SStatus 0 SControl 320) 952.516939] ata14.05: no reset method available, skipping reset 952.517234] ata14.05: SATA link up 1.5 Gbps (SStatus 113 SControl 300) 952.517977] ata14.00: ATA-7: Maxtor 6Y120M0, YAR51BW0, max UDMA/133 952.518145] ata14.00: 240121728 sectors, multi 0: LBA 952.518955] ata14.00: configured for UDMA/133 952.519905] ata14.03: ATA-7: Hitachi HUA721010KLA330, GKAOAB0A, max UDMA/133 952.520082] ata14.03: 1953525168 sectors, multi 0: LBA48 NCQ (depth 31/32), AA 952.521264] ata14.03: configured for UDMA/133 952.521443] ata14.03: device reported invalid CHS sector 0 952.521605] ata14.03: device reported invalid CHS sector 0 952.521761] sd 13:3:0:0: [sdc] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE 952.522053] sd 13:3:0:0: [sdc] Sense Key : Aborted Command [current] [descriptor] 952.522548] Descriptor sense data with sense descriptors (in hex): 952.522788] 72 0b 00 00 00 00 00 0c 00 0a 80 00 00 00 00 00 952.524111] 00 00 00 00 952.524591] sd 13:3:0:0: [sdc] Add. Sense: No additional sense information 952.524903] sd 13:3:0:0: [sdc] CDB: Read(10): 28 00 00 00 02 00 00 01 00 00 952.525980] end_request: I/O error, dev sdc, sector 512 952.526140] Buffer I/O error on device sdc, logical block 64 952.526306] Buffer I/O error on device sdc, logical block 65 952.526323] sd 13:3:0:0: rejecting I/O to offline device 952.526628] Buffer I/O error on device sdc, logical block 66 952.526630] Buffer I/O error on device sdc, logical block 67 952.526633] Buffer I/O error on device sdc, logical block 68 952.526635] Buffer I/O error on device sdc, logical block 69 952.526638] Buffer I/O error on device sdc, logical block 70 952.526640] Buffer I/O error on device sdc, logical block 71 952.526642] Buffer I/O error on device sdc, logical block 72 952.526644] Buffer I/O error on device sdc, logical block 73 952.526663] sd 13:3:0:0: [sdc] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE 952.526665] sd 13:3:0:0: [sdc] Sense Key : Aborted Command [current] [descriptor] 952.526668] Descriptor sense data with sense descriptors (in hex): 952.526686] 72 0b 00 00 00 00 00 0c 00 0a 80 00 00 00 00 00 952.526692] 00 00 00 00 952.526696] sd 13:3:0:0: [sdc] Add. Sense: No additional sense information 952.526716] sd 13:3:0:0: [sdc] CDB: Read(10): 28 00 00 00 03 00 00 01 00 00 952.526741] end_request: I/O error, dev sdc, sector 768 952.526811] ata14: EH complete 952.526848] ata14.00: detaching (SCSI 13:0:0:0) 952.531753] sd 13:3:0:0: rejecting I/O to offline device 952.531916] end_request: I/O error, dev sdc, sector 0 952.532078] sd 13:3:0:0: rejecting I/O to offline device 952.532239] end_request: I/O error, dev sdc, sector 0 952.544961] sd 13:0:0:0: [sdb] Synchronizing SCSI cache 952.545209] sd 13:0:0:0: [sdb] Stopping disk 952.653571] ata14.03: detaching (SCSI 13:3:0:0) 952.672917] sd 13:3:0:0: [sdc] Synchronizing SCSI cache 952.673212] sd 13:3:0:0: [sdc] Stopping disk 953.145975] scsi 13:0:0:0: Direct-Access ATA Maxtor 6Y120M0 YAR5 PQ: 0 ANSI: 5 953.146403] sd 13:0:0:0: [sdb] 240121728 512-byte logical blocks: (122 GB/114 GiB) 953.146428] scsi 13:3:0:0: Direct-Access ATA Hitachi HUA72101 GKAO PQ: 0 ANSI: 5 953.146614] sd 13:3:0:0: [sdc] 1953525168 512-byte logical blocks: (1.00 TB/931 GiB) 953.146666] sd 13:3:0:0: [sdc] Write Protect is off 953.146669] sd 13:3:0:0: [sdc] Mode Sense: 00 3a 00 00 953.146692] sd 13:3:0:0: [sdc] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA 953.147550] sd 13:0:0:0: [sdb] Write Protect is off 953.147710] sd 13:0:0:0: [sdb] Mode Sense: 00 3a 00 00 953.147739] sd 13:0:0:0: [sdb] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA 955.301412] sdc: sdc1 sdc2 < sdc5 > 955.301853] sd 13:3:0:0: [sdc] Attached SCSI disk 956.199755] sdb: sdb1 956.200134] sd 13:0:0:0: [sdb] Attached SCSI disk I hope this is of some help - if you can give any hints, I'm happy to try and dig a bit further (and/or if you'd like me to sent you any of the hardware involved, please let me know). Cheers! Tim. -- South East Open Source Solutions Limited Registered in England and Wales with company number 06134732. Registered Office: 2 Powell Gardens, Redhill, Surrey, RH1 1TQ VAT number: 900 6633 53 http://seoss.co.uk/ +44-(0)1273-808309 -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html