Problem description: ==================== A node with Adaptec 6405 controller, latest BIOS V5.3-0[19204] A lot of disks attached to the controller. Simple test: running mkfs.ext4 on many disks on the same controller in parallel (mkfs is not important here, any serious io load triggers controller aborts) Results: * no problems (controller resets) with kernels prior to 395e5df79a95 ("scsi: aacraid: Remove reference to Series-9") * latest ms kernel v5.2-rc6-15-g249155c20f9b - mkfs processes are in D state, lot of complains in logs like: [ 654.894633] aacraid: Host adapter abort request. aacraid: Outstanding commands on (0,1,43,0): [ 699.441034] aacraid: Host adapter abort request. aacraid: Outstanding commands on (0,1,40,0): [ 699.442950] aacraid: Host adapter reset request. SCSI hang ? [ 714.457428] aacraid: Host adapter reset request. SCSI hang ? ... [ 759.514759] aacraid: Host adapter reset request. SCSI hang ? [ 759.514869] aacraid 0000:03:00.0: outstanding cmd: midlevel-0 [ 759.514870] aacraid 0000:03:00.0: outstanding cmd: lowlevel-0 [ 759.514872] aacraid 0000:03:00.0: outstanding cmd: error handler-498 [ 759.514873] aacraid 0000:03:00.0: outstanding cmd: firmware-471 [ 759.514875] aacraid 0000:03:00.0: outstanding cmd: kernel-60 [ 759.514912] aacraid 0000:03:00.0: Controller reset type is 3 [ 759.515013] aacraid 0000:03:00.0: Issuing IOP reset [ 850.296705] aacraid 0000:03:00.0: IOP reset succeeded Same complains on Ubuntu kernel 4.15.0-50-generic: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1777586 Controller: =========== 03:00.0 RAID bus controller: Adaptec Series 6 - 6G SAS/PCIe 2 (rev 01) Subsystem: Adaptec Series 6 - ASR-6405 - 4 internal 6G SAS ports Test: ===== # cat dev.list /dev/sdq1 /dev/sde1 /dev/sds1 /dev/sdb1 /dev/sdk1 /dev/sdaj1 /dev/sdaf1 /dev/sdd1 /dev/sdac1 /dev/sdai1 /dev/sdz1 /dev/sdj1 /dev/sdy1 /dev/sdn1 /dev/sdae1 /dev/sdg1 /dev/sdi1 /dev/sdc1 /dev/sdf1 /dev/sdl1 /dev/sda1 /dev/sdab1 /dev/sdr1 /dev/sdo1 /dev/sdah1 /dev/sdm1 /dev/sdt1 /dev/sdp1 /dev/sdad1 /dev/sdh1 =========================================== # cat run_mkfs.sh #!/bin/bash while read i; do mkfs.ext4 $i -q -E lazy_itable_init=1 -O uninit_bg -m 0 & done ================================= # cat dev.list | ./run_mkfs.sh The issue is 100% reproducible. i've bisected to the culprit patch, it's 395e5df79a95 ("scsi: aacraid: Remove reference to Series-9") it changes arc ctrl checks for Series-6 controllers and i've checked that resurrection of original logic in arc ctrl checks eliminates controller hangs/resets. Konstantin Khorenko (2): Revert "scsi: aacraid: Remove reference to Series-9" scsi: aacraid: Remove references to Series-9 (only) drivers/scsi/aacraid/aacraid.h | 11 ----------- drivers/scsi/aacraid/comminit.c | 15 +++++++++++---- drivers/scsi/aacraid/commsup.c | 4 +++- drivers/scsi/aacraid/linit.c | 8 +++++--- 4 files changed, 19 insertions(+), 19 deletions(-) -- 2.15.1