Bernd, This looks OK for me, but I am not sure whether we should take this work-around to the upstream driver. As this is a workaround to avoid the deadlock and not the actual fix. I hope you can retain this with your in-house driver. May be James can comment whether we can take this into MPT driver or not? Thanks Sathya -----Original Message----- From: Bernd Schubert [mailto:bs@xxxxxxxxx] Sent: Tuesday, September 23, 2008 6:58 PM To: Linux SCSI Mailing List Cc: Moore, Eric; Prakash, Sathya; James Bottomley; DL-MPT Fusion Linux Subject: [ PATCH 3/4 ] mpt fusion prevent DV deadlock The mpt fusion driver will do a domain revalidation on an ioc reset, but this DV might cause a live deadlock. The problem has been entirely analyzed in this thread http://marc.info/?t=118039577800004, but so far none of the suggested solutions has been implemented. This patch simply disables the domain revalidation, if it does know it will run into the deadlock. Signed-off-by: Bernd Schubert <bs@xxxxxxxxx> drivers/message/fusion/mptspi.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) Index: linux-2.6.26/drivers/message/fusion/mptspi.c =================================================================== --- linux-2.6.26.orig/drivers/message/fusion/mptspi.c +++ linux-2.6.26/drivers/message/fusion/mptspi.c @@ -672,12 +672,24 @@ static void mptspi_dv_device(struct _MPT { VirtTarget *vtarget = scsi_target(sdev)->hostdata; MPT_ADAPTER *ioc = hd->ioc; + unsigned long nr_requests = sdev->request_queue->nr_requests; + struct request_list *rl = &sdev->request_queue->rq; /* no DV on RAID devices */ if (sdev->channel == 0 && mptspi_is_raid(hd, sdev->id)) return; + if (rl->count[0] + 1 >= nr_requests + || rl->count[1] + 1 >= nr_requests) { + /* we must NOT do a DV after an error recovery, when we + * don't have left a space in the request list, since + * this will cause a live dead lock */ + starget_printk(KERN_INFO, scsi_target(sdev), MYIOC_s_FMT + "Skipping DV, to prevent dead lock!\n", ioc->name); + return; + } + /* If this is a piece of a RAID, then quiesce first */ if (sdev->channel == 1 && mptscsih_quiesce_raid(hd, 1, vtarget->channel, vtarget->id) < 0) { -- Bernd Schubert Q-Leap Networks GmbH -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
