Date: Wed, 7 Feb 2001 21:12:39 -0700 From: "Kenneth D. Merry" <ken@kdm.org> To: Mike Smith <msmith@FreeBSD.ORG> Cc: Tom Samplonius <tom@sdf.com>, freebsd-scsi@FreeBSD.ORG Subject: Re: Tags and the mly driver Message-ID: <20010207211239.A7966@panzer.kdm.org> In-Reply-To: <200102080411.f184BH907296@mass.dis.org>; from msmith@FreeBSD.ORG on Wed, Feb 07, 2001 at 08:11:17PM -0800 References: <20010205155730.A85912@panzer.kdm.org> <200102080411.f184BH907296@mass.dis.org>
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On Wed, Feb 07, 2001 at 20:11:17 -0800, Mike Smith wrote: > > > How do we go about telling the transport layer that multiple commands per > > > target is OK, but that we don't care about tags? > > > > There are two numbers that get passed in to cam_sim_alloc(), the maximum > > number of untagged commands and the maximum number of tagged commands per > > device. > > > cam_sim_alloc(mly_cam_action, > mly_cam_poll, > "mly", > sc, > device_get_unit(sc->mly_dev), > max untagged -> 1, > max tagged -> sc->mly_controllerinfo->maximum_parallel_commands, > devq) Correct. > > Since the inquiry data from the Mylex array doesn't claim that it supports > > tagged queueing, the transport layer uses the number of untagged commands > > to determine how many transactions to send down at a time. > > Ah, ok. Since I create a separate sim for each channel, and since the > array devices are on virtual channels separate from the passthrough > devices, it should be relatively straightforward to adjust this > accordingly so that the untagged command limit is raised for the array > devices. That'll work. > > > Actually, the driver should probably block attempts to access the > > > enclosure device as well as disks listed in the array config, since the > > > controller is meant to handle these. The driver doesn't actually attach > > > to it - this is the generic CAM code. > > > > You could probably return selection timeouts for any device you didn't want > > CAM to talk to, if you have a way of knowing which devices those are. That > > would keep CAM from trying to talk to it. > > This is how I currently handle the disks that are part of the array. Cool! Ken -- Kenneth Merry ken@kdm.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message
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