1.\" $NetBSD: viaide.4,v 1.5 2005/02/02 14:35:40 wiz Exp $ 2.\" 3.\" Copyright (c) 2003 Manuel Bouyer. 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 9.\" notice, this list of conditions and the following disclaimer. 10.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" notice, this list of conditions and the following disclaimer in the 12.\" documentation and/or other materials provided with the distribution. 13.\" 3. All advertising materials mentioning features or use of this software 14.\" must display the following acknowledgement: 15.\" This product includes software developed by Manuel Bouyer. 16.\" 4. The name of the author may not be used to endorse or promote products 17.\" derived from this software without specific prior written permission. 18.\" 19.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 20.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 21.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 22.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 23.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 24.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27.\" INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 28.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29.\" 30.Dd February 2, 2005 31.Dt VIAIDE 4 32.Os 33.Sh NAME 34.Nm viaide 35.Nd AMD, NVIDIA and VIA IDE disk controllers driver 36.Sh SYNOPSIS 37.Cd "viaide* at pci? dev ? function ? flags 0x0000" 38.Cd "options PCIIDE_AMD756_ENABLEDMA" 39.Sh DESCRIPTION 40The 41.Nm 42driver supports the following IDE controllers 43and provides the interface with the hardware for the 44.Ic ata 45driver: 46.Bl -dash -compact -offset indent 47.It 48Advanced Micro Devices AMD-756, 766, and 768 IDE Controllers 49.It 50NVIDIA nForce, nForce2, nForce2 400, nForce3, nForce3 250, 51and nForce4 IDE Controllers 52.It 53VIA Technologies VT82C586, VT82C586A, VT82C596A, VT82C686A, VT8233A, 54VT8235 and VT8237 IDE Controllers, and VT6421 Serial RAID Controller 55.El 56.Pp 57The 0x0002 flag forces the 58.Nm 59driver to disable DMA on chipsets for which DMA would normally be 60enabled. 61This can be used as a debugging aid, or to work around 62problems where the IDE controller is wired up to the system incorrectly. 63.Sh SEE ALSO 64.Xr ata 4 , 65.Xr atapi 4 , 66.Xr intro 4 , 67.Xr pci 4 , 68.Xr pciide 4 , 69.Xr wd 4 , 70.Xr wdc 4 71.Sh NOTES 72Drives on the VT6421 Serial RAID Controller can only be accessed 73after they have been configured into RAID or JBOD sets via its 74BIOS. 75It is also inaptly named as it has both SATA and PATA interfaces. 76.Sh BUGS 77The AMD756 chip revision D2 has a bug affecting DMA (but not Ultra-DMA) 78modes. 79The workaround documented by AMD is to not use DMA on any drive which 80does not support Ultra-DMA modes. 81This does not appear to be necessary on all drives, the 82PCIIDE_AMD756_ENABLEDMA option can be used to force multiword DMA 83on the buggy revisions. 84Multiword DMA can eventually be disabled on a 85per-drive basis with config flags, see 86.Xr wd 4 . 87The bug, if triggered, will cause a total system hang. 88.Pp 89The timings used for the PIO and DMA modes for controllers listed above 90are for a PCI bus running at 30 or 33 MHz. 91This driver may not work properly on overclocked systems. 92