xref: /linux/Documentation/scsi/dc395x.rst (revision 3d0fe49454652117522f60bfbefb978ba0e5300b)
1.. SPDX-License-Identifier: GPL-2.0
2
3==================
4dc395x SCSI driver
5==================
6
7Status
8------
9The driver has been tested with CD-R and CD-R/W drives. These should
10be safe to use. Testing with hard disks has not been done to any
11great degree and caution should be exercised if you want to attempt
12to use this driver with hard disks.
13
14This driver is evolved from `the original 2.4 driver
15<https://web.archive.org/web/20140129181343/http://www.garloff.de/kurt/linux/dc395/>`_.
16Problems, questions and patches should be submitted to the `Linux SCSI
17mailing list <linux-scsi@vger.kernel.org>`_.
18
19Parameters
20----------
21The driver uses the settings from the EEPROM set in the SCSI BIOS
22setup. If there is no EEPROM, the driver uses default values.
23Both can be overridden by command line parameters (module or kernel
24parameters).
25
26The following parameters are available:
27
28safe
29   Default: 0, Acceptable values: 0 or 1
30
31   If safe is set to 1 then the adapter will use conservative
32   ("safe") default settings. This sets:
33
34		shortcut for dc395x=7,4,9,15,2,10
35
36adapter_id
37   Default: 7, Acceptable values: 0 to 15
38
39   Sets the host adapter SCSI ID.
40
41max_speed
42   Default: 1, Acceptable value: 0 to 7
43
44   ==  ========
45   0   20   Mhz
46   1   12.2 Mhz
47   2   10   Mhz
48   3   8    Mhz
49   4   6.7  Mhz
50   5   5.8  Hhz
51   6   5    Mhz
52   7   4    Mhz
53   ==  ========
54
55dev_mode
56   Bitmap for device configuration
57
58   DevMode bit definition:
59
60      === ======== ========  =========================================
61      Bit Val(hex) Val(dec)  Meaning
62      === ======== ========  =========================================
63       0    0x01       1     Parity check
64       1    0x02       2     Synchronous Negotiation
65       2    0x04       4     Disconnection
66       3    0x08       8     Send Start command on startup. (Not used)
67       4    0x10      16     Tagged Command Queueing
68       5    0x20      32     Wide Negotiation
69      === ======== ========  =========================================
70
71adapter_mode
72   Bitmap for adapter configuration
73
74   AdaptMode bit definition
75
76    ===== ======== ========  ====================================================
77      Bit Val(hex) Val(dec)  Meaning
78    ===== ======== ========  ====================================================
79       0    0x01       1     Support more than two drives. (Not used)
80       1    0x02       2     Use DOS compatible mapping for HDs greater than 1GB.
81       2    0x04       4     Reset SCSI Bus on startup.
82       3    0x08       8     Active Negation: Improves SCSI Bus noise immunity.
83       4    0x10      16     Immediate return on BIOS seek command. (Not used)
84    (*)5    0x20      32     Check for LUNs >= 1.
85    ===== ======== ========  ====================================================
86
87tags
88   Default: 3, Acceptable values: 0-5
89
90   The number of tags is 1<<x, if x has been specified
91
92reset_delay
93   Default: 1, Acceptable values: 0-180
94
95   The seconds to not accept commands after a SCSI Reset
96
97
98For the built  in driver the parameters should be prefixed with
99dc395x. (eg "dc395x.safe=1")
100
101
102Copyright
103---------
104The driver is free software. It is protected by the GNU General Public
105License (GPL). Please read it, before using this driver. It should be
106included in your kernel sources and with your distribution. It carries the
107filename COPYING. If you don't have it, please ask me to send you one by
108email.
109
110Note: The GNU GPL says also something about warranty and liability.
111Please be aware the following: While we do my best to provide a working and
112reliable driver, there is a chance, that it will kill your valuable data.
113We refuse to take any responsibility for that. The driver is provided as-is
114and YOU USE IT AT YOUR OWN RESPONSIBILITY.
115