| ahc.4 (23462) | ahc.4 (26282) |
|---|---|
| 1.\" 2.\" Copyright (c) 1995, 1996, 1997 3.\" Justin T. Gibbs. All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright --- 10 unchanged lines hidden (view full) --- 19.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26.\" | 1.\" 2.\" Copyright (c) 1995, 1996, 1997 3.\" Justin T. Gibbs. All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright --- 10 unchanged lines hidden (view full) --- 19.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26.\" |
| 27.\" $Id$ | 27.\" $Id: ahc.4,v 1.8 1997/03/07 02:49:44 jmg Exp $ |
| 28.\" 29.Dd April 20, 1996 30.Dt AHC 4 i386 31.Os FreeBSD 32.Sh NAME 33.Nm ahc 34.Nd Adaptec VL/EISA/PCI SCSI host adapter driver 35.Sh SYNOPSIS --- 71 unchanged lines hidden (view full) --- 107stop gap measure until a mechanism to detect these broken devices and to 108control this feature on a per device basis is in place. 109.Pp 110Memory mapped I/O can be enabled with the 111.Dq Dv AHC_ALLOW_MEMIO 112configuration option. 113Memory mapped I/O is more efficient than the alternative, programmed I/O. 114Most PCI BIOSes will map devices so that either technique for communicating | 28.\" 29.Dd April 20, 1996 30.Dt AHC 4 i386 31.Os FreeBSD 32.Sh NAME 33.Nm ahc 34.Nd Adaptec VL/EISA/PCI SCSI host adapter driver 35.Sh SYNOPSIS --- 71 unchanged lines hidden (view full) --- 107stop gap measure until a mechanism to detect these broken devices and to 108control this feature on a per device basis is in place. 109.Pp 110Memory mapped I/O can be enabled with the 111.Dq Dv AHC_ALLOW_MEMIO 112configuration option. 113Memory mapped I/O is more efficient than the alternative, programmed I/O. 114Most PCI BIOSes will map devices so that either technique for communicating |
| 115with the card is availible. | 115with the card is available. |
| 116In some cases, 117usually when the PCI device is sitting behind a PCI->PCI bridge, 118the BIOS fails to properly initialize the chip for memory mapped I/O. 119The symptom of this problem is usually a system hang if memory mapped I/O 120is attempted. 121Most modern motherboards perform the initialization correctly and work fine 122with this option enabled. 123.Pp 124Per target configuration performed in the 125.Tn SCSI-Select | 116In some cases, 117usually when the PCI device is sitting behind a PCI->PCI bridge, 118the BIOS fails to properly initialize the chip for memory mapped I/O. 119The symptom of this problem is usually a system hang if memory mapped I/O 120is attempted. 121Most modern motherboards perform the initialization correctly and work fine 122with this option enabled. 123.Pp 124Per target configuration performed in the 125.Tn SCSI-Select |
| 126menu, accesible at boot | 126menu, accessible at boot |
| 127in 128.No non- Ns Tn EISA 129models, 130or through an 131.Tn EISA 132configuration utility for 133.Tn EISA 134models, --- 48 unchanged lines hidden --- | 127in 128.No non- Ns Tn EISA 129models, 130or through an 131.Tn EISA 132configuration utility for 133.Tn EISA 134models, --- 48 unchanged lines hidden --- |