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Based on kernel version 3.16. Page generated on 2014-08-06 21:41 EST.

1	The tmscsim driver
2	==================
3	
4	1. Purpose and history
5	2. Installation
6	3. Features
7	4. Configuration via /proc/scsi/tmscsim/?
8	5. Configuration via boot/module params
9	6. Potential improvements
10	7. Bug reports, debugging and updates
11	8. Acknowledgements
12	9. Copyright
13	
14	
15	1. Purpose and history
16	----------------------
17	The tmscsim driver supports PCI SCSI Host Adapters based on the AM53C974
18	chip. AM53C974 based SCSI adapters include: 
19	 Tekram DC390, DC390T
20	 Dawicontrol 2974
21	 QLogic Fast! PCI Basic
22	 some on-board adapters
23	(This is most probably not a complete list)
24	
25	It has originally written by C.L. Huang from the Tekram corp. to support the
26	Tekram DC390(T) adapter. This is where the name comes from: tm = Tekram
27	scsi = SCSI driver, m = AMD (?) as opposed to w for the DC390W/U/F
28	(NCR53c8X5, X=2/7) driver. Yes, there was also a driver for the latter,
29	tmscsiw, which supported DC390W/U/F adapters. It's not maintained any more,
30	as the ncr53c8xx is perfectly supporting these adapters since some time.
31	
32	The driver first appeared in April 1996, exclusively supported the DC390 
33	and has been enhanced since then in various steps. In May 1998 support for 
34	general AM53C974 based adapters and some possibilities to configure it were
35	added. The non-DC390 support works by assuming some values for the data
36	normally taken from the DC390 EEPROM. See below (chapter 5) for details.
37	
38	When using the DC390, the configuration is still be done using the DC390
39	BIOS setup. The DC390 EEPROM is read and used by the driver, any boot or
40	module parameters (chapter 5) are ignored! However, you can change settings
41	dynamically, as described in chapter 4. 
42	
43	For a more detailed description of the driver's history, see the first lines
44	of tmscsim.c.
45	The numbering scheme isn't consistent. The first versions went from 1.00 to
46	1.12, then 1.20a to 1.20t. Finally I decided to use the ncr53c8xx scheme. So
47	the next revisions will be 2.0a to 2.0X (stable), 2.1a to 2.1X (experimental),
48	2.2a to 2.2X (stable, again) etc. (X = anything between a and z.) If I send
49	fixes to people for testing, I create intermediate versions with a digit 
50	appended, e.g. 2.0c3.
51	
52	
53	2. Installation
54	---------------
55	If you got any recent kernel with this driver and document included in
56	linux/drivers/scsi, you basically have to do nothing special to use this
57	driver. Of course you have to choose to compile SCSI support and DC390(T)
58	support into your kernel or as module when configuring your kernel for
59	compiling.
60	NEW: You may as well compile this module outside your kernel, using the
61	supplied Makefile.
62	
63	 If you got an old kernel (pre 2.1.127, pre 2.0.37p1) with an old version of
64	 this driver: Get dc390-21125-20b.diff.gz or dc390-2036p21-20b1.diff.gz from
65	 my web page and apply the patch. Apply further patches to upgrade to the 
66	 latest version of the driver.
67	
68	 If you want to do it manually, you should copy the files (dc390.h,
69	 tmscsim.h, tmscsim.c, scsiiom.c and README.tmscsim) from this directory to
70	 linux/drivers/scsi. You have to recompile your kernel/module of course.
71	
72	 You should apply the three patches included in dc390-120-kernel.diff
73	 (Applying them: cd /usr/src; patch -p0 <~/dc390-120-kernel.diff)
74	 The patches are against 2.1.125, so you might have to manually resolve
75	 rejections when applying to another kernel version.
76	
77	 The patches will update the kernel startup code to allow boot parameters to
78	 be passed to the driver, update the Documentation and finally offer you the
79	 possibility to omit the non-DC390 parts of the driver.
80	 (By selecting "Omit support for non DC390" you basically disable the
81	 emulation of a DC390 EEPROM for non DC390 adapters. This saves a few bytes
82	 of memory.)
83	
84	If you got a very old kernel without the tmscsim driver (pre 2.0.31)
85	I recommend upgrading your kernel. However, if you don't want to, please
86	contact me to get the appropriate patches.
87	
88	
89	Upgrading a SCSI driver is always a delicate thing to do. The 2.0 driver has
90	proven stable on many systems, but it's still a good idea to take some
91	precautions. In an ideal world you would have a full backup of your disks.
92	The world isn't ideal and most people don't have full backups (me neither).
93	So take at least the following measures:
94	* make your kernel remount the FS read-only on detecting an error:
95	  tune2fs -e remount-ro /dev/sd??
96	* have copies of your SCSI disk's partition tables on some safe location:
97	  dd if=/dev/sda of=/mnt/floppy/sda bs=512 count=1
98	  or just print it with:
99	  fdisk -l | lpr
100	* make sure you are able to boot Linux (e.g. from floppy disk using InitRD)
101	  if your SCSI disk gets corrupted. You can use 
102	  ftp://student.physik.uni-dortmund.de/pub/linux/kernel/bootdisk.gz
103	
104	One more warning: I used to overclock my PCI bus to 41.67 MHz. My Tekram
105	DC390F (Sym53c875) accepted this as well as my Millennium. But the Am53C974
106	produced errors and started to corrupt my disks. So don't do that! A 37.50
107	MHz PCI bus works for me, though, but I don't recommend using higher clocks
108	than the 33.33 MHz being in the PCI spec.
109	
110	If you want to share the IRQ with another device and the driver refuses to
111	do so, you might succeed with changing the DC390_IRQ type in tmscsim.c to 
112	IRQF_SHARED | IRQF_DISABLED.
113	
114	
115	3.Features
116	----------
117	- SCSI
118	 * Tagged command queueing
119	 * Sync speed up to 10 MHz
120	 * Disconnection
121	 * Multiple LUNs
122	
123	- General / Linux interface
124	 * Support for up to 4 AM53C974 adapters.
125	 * DC390 EEPROM usage or boot/module params
126	 * Information via cat /proc/scsi/tmscsim/?
127	 * Dynamically configurable by writing to /proc/scsi/tmscsim/?
128	 * Dynamic allocation of resources
129	 * SMP support: Locking on io_request lock (Linux 2.1/2.2) or adapter 
130	    specific locks (Linux 2.5?)
131	 * Uniform source code for Linux-2.x.y
132	 * Support for dyn. addition/removal of devices via add/remove-single-device
133	   (Try: echo "scsi add-single-device C B T U" >/proc/scsi/scsi 
134	    C = Controller, B = Bus, T = Target SCSI ID, U = Unit SCSI LUN.) 
135	    Use with care!
136	 * Try to use the partition table for the determination of the mapping
137	
138	
139	4. Configuration via /proc/scsi/tmscsim/?
140	-----------------------------------------
141	First of all look at the output of /proc/scsi/tmscsim/? by typing
142	 cat /proc/scsi/tmscsim/?
143	The "?" should be replaced by the SCSI host number. (The shell might do this
144	for you.)
145	You will see some info regarding the adapter and, at the end, a listing of
146	the attached devices and their settings.
147	
148	Here's an example:
149	garloff@kurt:/home/garloff > cat /proc/scsi/tmscsim/0
150	Tekram DC390/AM53C974 PCI SCSI Host Adapter, Driver Version 2.0e7 2000-11-28
151	SCSI Host Nr 1, AM53C974 Adapter Nr 0
152	IOPortBase 0xb000, IRQ 10
153	MaxID 8, MaxLUN 8, AdapterID 6, SelTimeout 250 ms, DelayReset 1 s
154	TagMaxNum 16, Status 0x00, ACBFlag 0x00, GlitchEater 24 ns
155	Statistics: Cmnds 1470165, Cmnds not sent directly 0, Out of SRB conds 0
156	            Lost arbitrations 587,  Sel. connected 0, Connected: No
157	Nr of attached devices: 4, Nr of DCBs: 4
158	Map of attached LUNs: 01 00 00 03 01 00 00 00
159	Idx ID LUN Prty Sync DsCn SndS TagQ NegoPeriod SyncSpeed SyncOffs MaxCmd
160	00  00  00  Yes  Yes  Yes  Yes  Yes   100 ns    10.0 M      15      16
161	01  03  00  Yes  Yes  Yes  Yes  No    100 ns    10.0 M      15      01
162	02  03  01  Yes  Yes  Yes  Yes  No    100 ns    10.0 M      15      01
163	03  04  00  Yes  Yes  Yes  Yes  No    100 ns    10.0 M      15      01
164	
165	Note that the settings MaxID and MaxLUN are not zero- but one-based, which
166	means that a setting MaxLUN=4, will result in the support of LUNs 0..3. This
167	is somehow inconvenient, but the way the mid-level SCSI code expects it to be.
168	
169	ACB and DCB are acronyms for Adapter Control Block and Device Control Block.
170	These are data structures of the driver containing information about the
171	adapter and the connected SCSI devices respectively.
172	
173	Idx is the device index (just a consecutive number for the driver), ID and
174	LUN are the SCSI ID and LUN, Prty means Parity checking, Sync synchronous
175	negotiation, DsCn Disconnection, SndS Send Start command on startup (not
176	used by the driver) and TagQ Tagged Command Queueing. NegoPeriod and
177	SyncSpeed are somehow redundant, because they are reciprocal values 
178	(1 / 112 ns = 8.9 MHz). At least in theory. The driver is able to adjust the
179	NegoPeriod more accurate (4ns) than the SyncSpeed (1 / 25ns). I don't know
180	if certain devices will have problems with this discrepancy. Max. speed is
181	10 MHz corresp. to a min. NegoPeriod of 100 ns. 
182	(The driver allows slightly higher speeds if the devices (Ultra SCSI) accept
183	it, but that's out of adapter spec, on your own risk and unlikely to improve
184	performance. You're likely to crash your disks.) 
185	SyncOffs is the offset used for synchronous negotiations; max. is 15. 
186	The last values are only shown, if Sync is enabled. (NegoPeriod is still
187	displayed in brackets to show the values which will be used after enabling
188	Sync.)
189	MaxCmd ist the number of commands (=tags) which can be processed at the same
190	time by the device.
191	
192	If you want to change a setting, you can do that by writing to
193	/proc/scsi/tmscsim/?. Basically you have to imitate the output of driver.
194	(Don't use the brackets for NegoPeriod on Sync disabled devices.)
195	You don't have to care about capitalisation. The driver will accept space,
196	tab, comma, = and : as separators.
197	
198	There are three kinds of changes: 
199	
200	(1) Change driver settings: 
201	    You type the names of the parameters and the params following it.
202	    Example:
203	     echo "MaxLUN=8 seltimeout 200" >/proc/scsi/tmscsim/0
204	
205	    Note that you can only change MaxID, MaxLUN, AdapterID, SelTimeOut,
206	    TagMaxNum, ACBFlag, GlitchEater and DelayReset. Don't change ACBFlag
207	    unless you want to see what happens, if the driver hangs.
208	
209	(2) Change device settings: You write a config line to the driver. The Nr
210	    must match the ID and LUN given. If you give "-" as parameter, it is
211	    ignored and the corresponding setting won't be changed. 
212	    You can use "y" or "n" instead of "Yes" and "No" if you want to.
213	    You don't need to specify a full line. The driver automatically performs
214	    an INQUIRY on the device if necessary to check if it is capable to operate
215	    with the given settings (Sync, TagQ).
216	    Examples:
217	     echo "0 0 0 y y y - y - 10 " >/proc/scsi/tmscsim/0
218	     echo "3 5 0 y n y " >/proc/scsi/tmscsim/0
219	
220	    To give a short explanation of the first example: 
221	    The first three numbers, "0 0 0" (Device index 0, SCSI ID 0, SCSI LUN 0),
222	    select the device to which the following parameters apply. Note that it
223	    would be sufficient to use the index or both SCSI ID and LUN, but I chose
224	    to require all three to have a syntax similar to the output.
225	    The following "y y y - y" enables Parity checking, enables Synchronous
226	    transfers, Disconnection, leaves Send Start (not used) untouched and
227	    enables Tagged Command Queueing for the selected device. The "-" skips
228	    the Negotiation Period setting but the "10" sets the max sync. speed to
229	    10 MHz. It's useless to specify both NegoPeriod and SyncSpeed as
230	    discussed above. The values used in this example will result in maximum
231	    performance.
232	
233	(3) Special commands: You can force a SCSI bus reset, an INQUIRY command, the
234	    removal or the addition of a device's DCB and a SCSI register dump.
235	    This is only used for debugging when you meet problems. The parameter of
236	    the INQUIRY and REMOVE commands is the device index as shown by the
237	    output of /proc/scsi/tmscsim/? in the device listing in the first column
238	    (Idx). ADD takes the SCSI ID and LUN.
239	    Examples:
240	     echo "reset" >/proc/scsi/tmscsim/0
241	     echo "inquiry 1" >/proc/scsi/tmscsim/0
242	     echo "remove 2" >/proc/scsi/tmscsim/1
243	     echo "add 2 3" >/proc/scsi/tmscsim/?
244	     echo "dump" >/proc/scsi/tmscsim/0
245	
246	    Note that you will meet problems when you REMOVE a device's DCB with the
247	    remove command if it contains partitions which are mounted. Only use it
248	    after unmounting its partitions, telling the SCSI mid-level code to
249	    remove it (scsi remove-single-device) and you really need a few bytes of
250	    memory.
251	    The ADD command allows you to configure a device before you tell the
252	    mid-level code to try detection.
253	
254	
255	I'd suggest reviewing the output of /proc/scsi/tmscsim/? after changing
256	settings to see if everything changed as requested.
257	
258	
259	5. Configuration via boot/module parameters
260	-------------------------------------------
261	With the DC390, the driver reads its EEPROM settings and tries to use them.
262	But you may want to override the settings prior to being able to change the
263	driver configuration via /proc/scsi/tmscsim/?.
264	If you do have another AM53C974 based adapter, that's even the only
265	possibility to adjust settings before you are able to write to the
266	/proc/scsi/tmscsim/? pseudo-file, e.g. if you want to use another 
267	adapter ID than 7.  
268	(BTW, the log message "DC390: No EEPROM found!" is normal without a DC390.)
269	For this purpose, you can pass options to the driver before it is initialised
270	by using kernel or module parameters. See lilo(8) or modprobe(1) manual
271	pages on how to pass params to the kernel or a module.
272	[NOTE: Formerly, it was not possible to override the EEPROM supplied
273	 settings of the DC390 with cmd line parameters. This has changed since
274	 2.0e7]
275	
276	The syntax of the params is much shorter than the syntax of the /proc/...
277	interface. This makes it a little bit more difficult to use. However, long
278	parameter lines have the risk to be misinterpreted and the length of kernel
279	parameters is limited.
280	
281	As the support for non-DC390 adapters works by simulating the values of the
282	DC390 EEPROM, the settings are given in a DC390 BIOS' way.
283	
284	Here's the syntax:
285	tmscsim=AdaptID,SpdIdx,DevMode,AdaptMode,TaggedCmnds,DelayReset
286	
287	Each of the parameters is a number, containing the described information:
288	
289	* AdaptID: The SCSI ID of the host adapter. Must be in the range 0..7
290	  Default is 7.
291	
292	* SpdIdx: The index of the maximum speed as in the DC390 BIOS. The values
293	  0..7 mean 10, 8.0, 6.7, 5.7, 5.0, 4.0, 3.1 and 2 MHz resp. Default is
294	  0 (10.0 MHz).
295	
296	* DevMode is a bit mapped value describing the per-device features. It
297	  applies to all devices. (Sync, Disc and TagQ will only apply, if the
298	  device supports it.) The meaning of the bits (* = default):
299	
300	   Bit Val(hex) Val(dec)  Meaning
301	   *0	 0x01	    1	  Parity check
302	   *1	 0x02	    2	  Synchronous Negotiation
303	   *2	 0x04	    4	  Disconnection
304	   *3	 0x08	    8	  Send Start command on startup. (Not used)
305	   *4	 0x10	   16	  Tagged Command Queueing
306	
307	  As usual, the desired value is obtained by adding the wanted values. If
308	  you want to enable all values, e.g., you would use 31(0x1f). Default is 31.
309	
310	* AdaptMode is a bit mapped value describing the enabled adapter features.
311	
312	   Bit Val(hex) Val(dec)  Meaning
313	   *0	 0x01	    1	  Support more than two drives. (Not used)
314	   *1	 0x02	    2	  Use DOS compatible mapping for HDs greater than 1GB.
315	   *2	 0x04	    4	  Reset SCSI Bus on startup.
316	   *3	 0x08	    8	  Active Negation: Improves SCSI Bus noise immunity.
317	    4	 0x10	   16	  Immediate return on BIOS seek command. (Not used)
318	 (*)5	 0x20	   32	  Check for LUNs >= 1.
319	  
320	  The default for LUN Check depends on CONFIG_SCSI_MULTI_LUN.
321	
322	* TaggedCmnds is a number indicating the maximum number of Tagged Commands.
323	  It is the binary logarithm - 1 of the actual number. Max is 4 (32).
324	   Value  Number of Tagged Commands
325	     0		 2
326	     1		 4
327	     2		 8
328	    *3		16
329	     4		32
330	
331	* DelayReset is the time in seconds (minus 0.5s), the adapter waits, after a
332	  bus reset. Default is 1 (corresp. to 1.5s).
333	
334	Example:
335	 modprobe tmscsim tmscsim=6,2,31
336	would set the adapter ID to 6, max. speed to 6.7 MHz, enable all device
337	features and leave the adapter features, the number of Tagged Commands
338	and the Delay after a reset to the defaults.
339	
340	As you can see, you don't need to specify all of the six params.
341	If you want values to be ignored (i.e. the EEprom settings or the defaults
342	will be used), you may pass -2 (not 0!) at the corresponding position.
343	
344	The defaults (7,0,31,15,3,1) are aggressive to allow good performance. You
345	can use tmscsim=7,0,31,63,4,0 for maximum performance, if your SCSI chain
346	allows it. If you meet problems, you can use tmscsim=-1 which is a shortcut
347	for tmscsim=7,4,9,15,2,10.
348	
349	
350	6. Potential improvements
351	-------------------------
352	Most of the intended work on the driver has been done. Here are a few ideas
353	to further improve its usability:
354	
355	* Cleanly separate per-Target and per-LUN properties (DCB)
356	* More intelligent abort() routine
357	* Use new_eh code (Linux-2.1+)
358	* Have the mid-level (ML) code (and not the driver) handle more of the
359	  various conditions.
360	* Command queueing in the driver: Eliminate Query list and use ML instead.
361	* More user friendly boot/module param syntax
362	
363	Further investigation on these problems:
364	
365	* Driver hangs with sync readcdda (xcdroast) (most probably VIA PCI error)
366	
367	Known problems: 
368	Please see http://www.garloff.de/kurt/linux/dc390/problems.html
369	
370	* Changing the parameters of multi-lun by the tmscsim/? interface will
371	  cause problems, cause these settings are mostly per Target and not per LUN
372	  and should be updated accordingly. To be fixed for 2.0d24.
373	* CDRs (eg Yam CRW4416) not recognized, because some buggy devices don't 
374	  recover from a SCSI reset in time. Use a higher delay or don't issue
375	  a SCSI bus reset on driver initialization. See problems page.
376	  For the CRW4416S, this seems to be solved with firmware 1.0g (reported by 
377	  Jean-Yves Barbier).
378	* TEAC CD-532S not being recognized. (Works with 1.11).
379	* Scanners (eg. Astra UMAX 1220S) don't work: Disable Sync Negotiation.
380	  If this does not help, try echo "INQUIRY t" >/proc/scsi/tmscsim/? (t
381	  replaced by the dev index of your scanner). You may try to reset your SCSI
382	  bus afterwards (echo "RESET" >/proc/scsi/tmscsim/?).
383	  The problem seems to be solved as of 2.0d18, thanks to Andreas Rick.
384	* If there is a valid partition table, the driver will use it for determining
385	  the mapping. If there's none, a reasonable mapping (Symbios-like) will be
386	  assumed. Other operating systems may not like this mapping, though
387	  it's consistent with the BIOS' behaviour. Old DC390 drivers ignored the
388	  partition table and used a H/S = 64/32 or 255/63 translation. So if you
389	  want to be compatible to those, use this old mapping when creating
390	  partition tables. Even worse, on bootup the DC390 might complain if other
391	  mappings are found, so auto rebooting may fail.
392	* In some situations, the driver will get stuck in an abort loop. This is a
393	  bad interaction between the Mid-Layer of Linux' SCSI code and the driver.
394	  Try to disable DsCn, if you meet this problem. Please contact me for
395	  further debugging.
396	
397	
398	7. Bug reports, debugging and updates
399	-------------------------------------
400	Whenever you have problems with the driver, you are invited to ask the
401	author for help. However, I'd suggest reading the docs and trying to solve
402	the problem yourself, first. 
403	If you find something, which you believe to be a bug, please report it to me. 
404	Please append the output of /proc/scsi/scsi, /proc/scsi/tmscsim/? and
405	maybe the DC390 log messages to the report. 
406	
407	Bug reports should be send to me (Kurt Garloff <dc390@garloff.de>) as well
408	as to the linux-scsi list (<linux-scsi@vger.kernel.org>), as sometimes bugs
409	are caused by the SCSI mid-level code.
410	
411	I will ask you for some more details and probably I will also ask you to
412	enable some of the DEBUG options in the driver (tmscsim.c:DC390_DEBUGXXX
413	defines). The driver will produce some data for the syslog facility then.
414	Beware: If your syslog gets written to a SCSI disk connected to your
415	AM53C974, the logging might produce log output again, and you might end
416	having your box spending most of its time doing the logging.
417	
418	The latest version of the driver can be found at:
419	 http://www.garloff.de/kurt/linux/dc390/
420	 ftp://ftp.suse.com/pub/people/garloff/linux/dc390/
421	
422	
423	8. Acknowledgements
424	-------------------
425	Thanks to Linus Torvalds, Alan Cox, the FSF people, the XFree86 team and 
426	all the others for the wonderful OS and software.
427	Thanks to C.L. Huang and Philip Giang (Tekram) for the initial driver
428	release and support.
429	Thanks to Doug Ledford, Gérard Roudier for support with SCSI coding.
430	Thanks to a lot of people (espec. Chiaki Ishikawa, Andreas Haumer, Hubert 
431	Tonneau) for intensively testing the driver (and even risking data loss
432	doing this during early revisions).
433	Recently, SuSE GmbH, Nuernberg, FRG, has been paying me for the driver
434	development and maintenance. Special thanks!
435	
436	
437	9. Copyright
438	------------
439	 This driver is free software; you can redistribute it and/or modify
440	 it under the terms of the GNU General Public License as published by   
441	 the Free Software Foundation; version 2 of the License.
442	 If you want to use any later version of the GNU GPL, you will probably
443	 be allowed to, but you have to ask me and Tekram <erich@tekram.com.tw>
444	 before.
445	
446	-------------------------------------------------------------------------
447	Written by Kurt Garloff <kurt@garloff.de> 1998/06/11
448	Last updated 2000/11/28, driver revision 2.0e7
449	$Id: README.tmscsim,v 2.25.2.7 2000/12/20 01:07:12 garloff Exp $
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