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diff --git a/Documentation/scsi/tmscsim.txt b/Documentation/scsi/tmscsim.txt new file mode 100644 index 0000000..e165229 --- /dev/null +++ b/Documentation/scsi/tmscsim.txt @@ -0,0 +1,449 @@ +The tmscsim driver +================== + +1. Purpose and history +2. Installation +3. Features +4. Configuration via /proc/scsi/tmscsim/? +5. Configuration via boot/module params +6. Potential improvements +7. Bug reports, debugging and updates +8. Acknowledgements +9. Copyright + + +1. Purpose and history +---------------------- +The tmscsim driver supports PCI SCSI Host Adapters based on the AM53C974 +chip. AM53C974 based SCSI adapters include: + Tekram DC390, DC390T + Dawicontrol 2974 + QLogic Fast! PCI Basic + some on-board adapters +(This is most probably not a complete list) + +It has originally written by C.L. Huang from the Tekram corp. to support the +Tekram DC390(T) adapter. This is where the name comes from: tm = Tekram +scsi = SCSI driver, m = AMD (?) as opposed to w for the DC390W/U/F +(NCR53c8X5, X=2/7) driver. Yes, there was also a driver for the latter, +tmscsiw, which supported DC390W/U/F adapters. It's not maintained any more, +as the ncr53c8xx is perfectly supporting these adpaters since some time. + +The driver first appeared in April 1996, exclusively supported the DC390 +and has been enhanced since then in various steps. In May 1998 support for +general AM53C974 based adapters and some possibilities to configure it were +added. The non-DC390 support works by assuming some values for the data +normally taken from the DC390 EEPROM. See below (chapter 5) for details. + +When using the DC390, the configuration is still be done using the DC390 +BIOS setup. The DC390 EEPROM is read and used by the driver, any boot or +module parameters (chapter 5) are ignored! However, you can change settings +dynamically, as described in chapter 4. + +For a more detailed description of the driver's history, see the first lines +of tmscsim.c. +The numbering scheme isn't consistent. The first versions went from 1.00 to +1.12, then 1.20a to 1.20t. Finally I decided to use the ncr53c8xx scheme. So +the next revisions will be 2.0a to 2.0X (stable), 2.1a to 2.1X (experimental), +2.2a to 2.2X (stable, again) etc. (X = anything between a and z.) If I send +fixes to people for testing, I create intermediate versions with a digit +appended, e.g. 2.0c3. + + +2. Installation +--------------- +If you got any recent kernel with this driver and document included in +linux/drivers/scsi, you basically have to do nothing special to use this +driver. Of course you have to choose to compile SCSI support and DC390(T) +support into your kernel or as module when configuring your kernel for +compiling. +NEW: You may as well compile this module outside your kernel, using the +supplied Makefile. + + If you got an old kernel (pre 2.1.127, pre 2.0.37p1) with an old version of + this driver: Get dc390-21125-20b.diff.gz or dc390-2036p21-20b1.diff.gz from + my web page and apply the patch. Apply further patches to upgrade to the + latest version of the driver. + + If you want to do it manually, you should copy the files (dc390.h, + tmscsim.h, tmscsim.c, scsiiom.c and README.tmscsim) from this directory to + linux/drivers/scsi. You have to recompile your kernel/module of course. + + You should apply the three patches included in dc390-120-kernel.diff + (Applying them: cd /usr/src; patch -p0 <~/dc390-120-kernel.diff) + The patches are against 2.1.125, so you might have to manually resolve + rejections when applying to another kernel version. + + The patches will update the kernel startup code to allow boot parameters to + be passed to the driver, update the Documentation and finally offer you the + possibility to omit the non-DC390 parts of the driver. + (By selecting "Omit support for non DC390" you basically disable the + emulation of a DC390 EEPROM for non DC390 adapters. This saves a few bytes + of memory.) + +If you got a very old kernel without the tmscsim driver (pre 2.0.31) +I recommend upgrading your kernel. However, if you don't want to, please +contact me to get the appropriate patches. + + +Upgrading a SCSI driver is always a delicate thing to do. The 2.0 driver has +proven stable on many systems, but it's still a good idea to take some +precautions. In an ideal world you would have a full backup of your disks. +The world isn't ideal and most people don't have full backups (me neither). +So take at least the following measures: +* make your kernel remount the FS read-only on detecting an error: + tune2fs -e remount-ro /dev/sd?? +* have copies of your SCSI disk's partition tables on some safe location: + dd if=/dev/sda of=/mnt/floppy/sda bs=512 count=1 + or just print it with: + fdisk -l | lpr +* make sure you are able to boot Linux (e.g. from floppy disk using InitRD) + if your SCSI disk gets corrupted. You can use + ftp://student.physik.uni-dortmund.de/pub/linux/kernel/bootdisk.gz + +One more warning: I used to overclock my PCI bus to 41.67 MHz. My Tekram +DC390F (Sym53c875) accepted this as well as my Millenium. But the Am53C974 +produced errors and started to corrupt my disks. So don't do that! A 37.50 +MHz PCI bus works for me, though, but I don't recommend using higher clocks +than the 33.33 MHz being in the PCI spec. + +If you want to share the IRQ with another device and the driver refuses to +do so, you might succeed with changing the DC390_IRQ type in tmscsim.c to +SA_SHIRQ | SA_INTERRUPT. + + +3.Features +---------- +- SCSI + * Tagged command queueing + * Sync speed up to 10 MHz + * Disconnection + * Multiple LUNs + +- General / Linux interface + * Support for up to 4 AM53C974 adapters. + * DC390 EEPROM usage or boot/module params + * Information via cat /proc/scsi/tmscsim/? + * Dynamically configurable by writing to /proc/scsi/tmscsim/? + * Dynamic allocation of resources + * SMP support: Locking on io_request lock (Linux 2.1/2.2) or adapter + specific locks (Linux 2.5?) + * Uniform source code for Linux-2.x.y + * Support for dyn. addition/removal of devices via add/remove-single-device + (Try: echo "scsi add-single-device C B T U" >/proc/scsi/scsi + C = Controller, B = Bus, T = Target SCSI ID, U = Unit SCSI LUN.) + Use with care! + * Try to use the partition table for the determination of the mapping + + +4. Configuration via /proc/scsi/tmscsim/? +----------------------------------------- +First of all look at the output of /proc/scsi/tmscsim/? by typing + cat /proc/scsi/tmscsim/? +The "?" should be replaced by the SCSI host number. (The shell might do this +for you.) +You will see some info regarding the adapter and, at the end, a listing of +the attached devices and their settings. + +Here's an example: +garloff@kurt:/home/garloff > cat /proc/scsi/tmscsim/0 +Tekram DC390/AM53C974 PCI SCSI Host Adapter, Driver Version 2.0e7 2000-11-28 +SCSI Host Nr 1, AM53C974 Adapter Nr 0 +IOPortBase 0xb000, IRQ 10 +MaxID 8, MaxLUN 8, AdapterID 6, SelTimeout 250 ms, DelayReset 1 s +TagMaxNum 16, Status 0x00, ACBFlag 0x00, GlitchEater 24 ns +Statistics: Cmnds 1470165, Cmnds not sent directly 0, Out of SRB conds 0 + Lost arbitrations 587, Sel. connected 0, Connected: No +Nr of attached devices: 4, Nr of DCBs: 4 +Map of attached LUNs: 01 00 00 03 01 00 00 00 +Idx ID LUN Prty Sync DsCn SndS TagQ NegoPeriod SyncSpeed SyncOffs MaxCmd +00 00 00 Yes Yes Yes Yes Yes 100 ns 10.0 M 15 16 +01 03 00 Yes Yes Yes Yes No 100 ns 10.0 M 15 01 +02 03 01 Yes Yes Yes Yes No 100 ns 10.0 M 15 01 +03 04 00 Yes Yes Yes Yes No 100 ns 10.0 M 15 01 + +Note that the settings MaxID and MaxLUN are not zero- but one-based, which +means that a setting MaxLUN=4, will result in the support of LUNs 0..3. This +is somehow inconvenient, but the way the mid-level SCSI code expects it to be. + +ACB and DCB are acronyms for Adapter Control Block and Device Control Block. +These are data structures of the driver containing information about the +adapter and the connected SCSI devices respectively. + +Idx is the device index (just a consecutive number for the driver), ID and +LUN are the SCSI ID and LUN, Prty means Parity checking, Sync synchronous +negotiation, DsCn Disconnection, SndS Send Start command on startup (not +used by the driver) and TagQ Tagged Command Queueing. NegoPeriod and +SyncSpeed are somehow redundant, because they are reciprocal values +(1 / 112 ns = 8.9 MHz). At least in theory. The driver is able to adjust the +NegoPeriod more accurate (4ns) than the SyncSpeed (1 / 25ns). I don't know +if certain devices will have problems with this discrepancy. Max. speed is +10 MHz corresp. to a min. NegoPeriod of 100 ns. +(The driver allows slightly higher speeds if the devices (Ultra SCSI) accept +it, but that's out of adapter spec, on your own risk and unlikely to improve +performance. You're likely to crash your disks.) +SyncOffs is the offset used for synchronous negotiations; max. is 15. +The last values are only shown, if Sync is enabled. (NegoPeriod is still +displayed in brackets to show the values which will be used after enabling +Sync.) +MaxCmd ist the number of commands (=tags) which can be processed at the same +time by the device. + +If you want to change a setting, you can do that by writing to +/proc/scsi/tmscsim/?. Basically you have to imitate the output of driver. +(Don't use the brackets for NegoPeriod on Sync disabled devices.) +You don't have to care about capitalisation. The driver will accept space, +tab, comma, = and : as separators. + +There are three kinds of changes: + +(1) Change driver settings: + You type the names of the parameters and the params following it. + Example: + echo "MaxLUN=8 seltimeout 200" >/proc/scsi/tmscsim/0 + + Note that you can only change MaxID, MaxLUN, AdapterID, SelTimeOut, + TagMaxNum, ACBFlag, GlitchEater and DelayReset. Don't change ACBFlag + unless you want to see what happens, if the driver hangs. + +(2) Change device settings: You write a config line to the driver. The Nr + must match the ID and LUN given. If you give "-" as parameter, it is + ignored and the corresponding setting won't be changed. + You can use "y" or "n" instead of "Yes" and "No" if you want to. + You don't need to specify a full line. The driver automatically performs + an INQUIRY on the device if necessary to check if it is capable to operate + with the given settings (Sync, TagQ). + Examples: + echo "0 0 0 y y y - y - 10 " >/proc/scsi/tmscsim/0 + echo "3 5 0 y n y " >/proc/scsi/tmscsim/0 + + To give a short explanation of the first example: + The first three numbers, "0 0 0" (Device index 0, SCSI ID 0, SCSI LUN 0), + select the device to which the following parameters apply. Note that it + would be sufficient to use the index or both SCSI ID and LUN, but I chose + to require all three to have a syntax similar to the output. + The following "y y y - y" enables Parity checking, enables Synchronous + transfers, Disconnection, leaves Send Start (not used) untouched and + enables Tagged Command Queueing for the selected device. The "-" skips + the Negotiation Period setting but the "10" sets the max sync. speed to + 10 MHz. It's useless to specify both NegoPeriod and SyncSpeed as + discussed above. The values used in this example will result in maximum + performance. + +(3) Special commands: You can force a SCSI bus reset, an INQUIRY command, the + removal or the addition of a device's DCB and a SCSI register dump. + This is only used for debugging when you meet problems. The parameter of + the INQUIRY and REMOVE commands is the device index as shown by the + output of /proc/scsi/tmscsim/? in the device listing in the first column + (Idx). ADD takes the SCSI ID and LUN. + Examples: + echo "reset" >/proc/scsi/tmscsim/0 + echo "inquiry 1" >/proc/scsi/tmscsim/0 + echo "remove 2" >/proc/scsi/tmscsim/1 + echo "add 2 3" >/proc/scsi/tmscsim/? + echo "dump" >/proc/scsi/tmscsim/0 + + Note that you will meet problems when you REMOVE a device's DCB with the + remove command if it contains partitions which are mounted. Only use it + after unmounting its partitions, telling the SCSI mid-level code to + remove it (scsi remove-single-device) and you really need a few bytes of + memory. + The ADD command allows you to configure a device before you tell the + mid-level code to try detection. + + +I'd suggest reviewing the output of /proc/scsi/tmscsim/? after changing +settings to see if everything changed as requested. + + +5. Configuration via boot/module parameters +------------------------------------------- +With the DC390, the driver reads its EEPROM settings and tries to use them. +But you may want to override the settings prior to being able to change the +driver configuration via /proc/scsi/tmscsim/?. +If you do have another AM53C974 based adapter, that's even the only +possibility to adjust settings before you are able to write to the +/proc/scsi/tmscsim/? pseudo-file, e.g. if you want to use another +adapter ID than 7. +(BTW, the log message "DC390: No EEPROM found!" is normal without a DC390.) +For this purpose, you can pass options to the driver before it is initialised +by using kernel or module parameters. See lilo(8) or modprobe(1) manual +pages on how to pass params to the kernel or a module. +[NOTE: Formerly, it was not possible to override the EEPROM supplied + settings of the DC390 with cmd line parameters. This has changed since + 2.0e7] + +The syntax of the params is much shorter than the syntax of the /proc/... +interface. This makes it a little bit more difficult to use. However, long +parameter lines have the risk to be misinterpreted and the length of kernel +parameters is limited. + +As the support for non-DC390 adapters works by simulating the values of the +DC390 EEPROM, the settings are given in a DC390 BIOS' way. + +Here's the syntax: +tmscsim=AdaptID,SpdIdx,DevMode,AdaptMode,TaggedCmnds,DelayReset + +Each of the parameters is a number, containing the described information: + +* AdaptID: The SCSI ID of the host adapter. Must be in the range 0..7 + Default is 7. + +* SpdIdx: The index of the maximum speed as in the DC390 BIOS. The values + 0..7 mean 10, 8.0, 6.7, 5.7, 5.0, 4.0, 3.1 and 2 MHz resp. Default is + 0 (10.0 MHz). + +* DevMode is a bit mapped value describing the per-device features. It + applies to all devices. (Sync, Disc and TagQ will only apply, if the + device supports it.) The meaning of the bits (* = default): + + Bit Val(hex) Val(dec) Meaning + *0 0x01 1 Parity check + *1 0x02 2 Synchronous Negotiation + *2 0x04 4 Disconnection + *3 0x08 8 Send Start command on startup. (Not used) + *4 0x10 16 Tagged Command Queueing + + As usual, the desired value is obtained by adding the wanted values. If + you want to enable all values, e.g., you would use 31(0x1f). Default is 31. + +* AdaptMode is a bit mapped value describing the enabled adapter features. + + Bit Val(hex) Val(dec) Meaning + *0 0x01 1 Support more than two drives. (Not used) + *1 0x02 2 Use DOS compatible mapping for HDs greater than 1GB. + *2 0x04 4 Reset SCSI Bus on startup. + *3 0x08 8 Active Negation: Improves SCSI Bus noise immunity. + 4 0x10 16 Immediate return on BIOS seek command. (Not used) + (*)5 0x20 32 Check for LUNs >= 1. + + The default for LUN Check depends on CONFIG_SCSI_MULTI_LUN. + +* TaggedCmnds is a number indicating the maximum number of Tagged Commands. + It is the binary logarithm - 1 of the actual number. Max is 4 (32). + Value Number of Tagged Commands + 0 2 + 1 4 + 2 8 + *3 16 + 4 32 + +* DelayReset is the time in seconds (minus 0.5s), the adapter waits, after a + bus reset. Default is 1 (corresp. to 1.5s). + +Example: + modprobe tmscsim tmscsim=6,2,31 +would set the adapter ID to 6, max. speed to 6.7 MHz, enable all device +features and leave the adapter features, the number of Tagged Commands +and the Delay after a reset to the defaults. + +As you can see, you don't need to specify all of the six params. +If you want values to be ignored (i.e. the EEprom settings or the defaults +will be used), you may pass -2 (not 0!) at the corresponding position. + +The defaults (7,0,31,15,3,1) are aggressive to allow good performance. You +can use tmscsim=7,0,31,63,4,0 for maximum performance, if your SCSI chain +allows it. If you meet problems, you can use tmscsim=-1 which is a shortcut +for tmscsim=7,4,9,15,2,10. + + +6. Potential improvements +------------------------- +Most of the intended work on the driver has been done. Here are a few ideas +to further improve its usability: + +* Cleanly separate per-Target and per-LUN properties (DCB) +* More intelligent abort() routine +* Use new_eh code (Linux-2.1+) +* Have the mid-level (ML) code (and not the driver) handle more of the + various conditions. +* Command queueing in the driver: Eliminate Query list and use ML instead. +* More user friendly boot/module param syntax + +Further investigation on these problems: + +* Driver hangs with sync readcdda (xcdroast) (most probably VIA PCI error) + +Known problems: +Please see http://www.garloff.de/kurt/linux/dc390/problems.html + +* Changing the parameters of multi-lun by the tmscsim/? interface will + cause problems, cause these settings are mostly per Target and not per LUN + and should be updated accordingly. To be fixed for 2.0d24. +* CDRs (eg Yam CRW4416) not recognized, because some buggy devices don't + recover from a SCSI reset in time. Use a higher delay or don't issue + a SCSI bus reset on driver initialization. See problems page. + For the CRW4416S, this seems to be solved with firmware 1.0g (reported by + Jean-Yves Barbier). +* TEAC CD-532S not being recognized. (Works with 1.11). +* Scanners (eg. Astra UMAX 1220S) don't work: Disable Sync Negotiation. + If this does not help, try echo "INQUIRY t" >/proc/scsi/tmscsim/? (t + replaced by the dev index of your scanner). You may try to reset your SCSI + bus afterwards (echo "RESET" >/proc/scsi/tmscsim/?). + The problem seems to be solved as of 2.0d18, thanks to Andreas Rick. +* If there is a valid partition table, the driver will use it for determing + the mapping. If there's none, a reasonable mapping (Symbios-like) will be + assumed. Other operating systems may not like this mapping, though + it's consistent with the BIOS' behaviour. Old DC390 drivers ignored the + partition table and used a H/S = 64/32 or 255/63 translation. So if you + want to be compatible to those, use this old mapping when creating + partition tables. Even worse, on bootup the DC390 might complain if other + mappings are found, so auto rebooting may fail. +* In some situations, the driver will get stuck in an abort loop. This is a + bad interaction between the Mid-Layer of Linux' SCSI code and the driver. + Try to disable DsCn, if you meet this problem. Please contact me for + further debugging. + + +7. Bug reports, debugging and updates +------------------------------------- +Whenever you have problems with the driver, you are invited to ask the +author for help. However, I'd suggest reading the docs and trying to solve +the problem yourself, first. +If you find something, which you believe to be a bug, please report it to me. +Please append the output of /proc/scsi/scsi, /proc/scsi/tmscsim/? and +maybe the DC390 log messages to the report. + +Bug reports should be send to me (Kurt Garloff <dc390@garloff.de>) as well +as to the linux-scsi list (<linux-scsi@vger.kernel.org>), as sometimes bugs +are caused by the SCSI mid-level code. + +I will ask you for some more details and probably I will also ask you to +enable some of the DEBUG options in the driver (tmscsim.c:DC390_DEBUGXXX +defines). The driver will produce some data for the syslog facility then. +Beware: If your syslog gets written to a SCSI disk connected to your +AM53C974, the logging might produce log output again, and you might end +having your box spending most of its time doing the logging. + +The latest version of the driver can be found at: + http://www.garloff.de/kurt/linux/dc390/ + ftp://ftp.suse.com/pub/people/garloff/linux/dc390/ + + +8. Acknowledgements +------------------- +Thanks to Linus Torvalds, Alan Cox, the FSF people, the XFree86 team and +all the others for the wonderful OS and software. +Thanks to C.L. Huang and Philip Giang (Tekram) for the initial driver +release and support. +Thanks to Doug Ledford, Gérard Roudier for support with SCSI coding. +Thanks to a lot of people (espec. Chiaki Ishikawa, Andreas Haumer, Hubert +Tonneau) for intensively testing the driver (and even risking data loss +doing this during early revisions). +Recently, SuSE GmbH, Nuernberg, FRG, has been paying me for the driver +development and maintenance. Special thanks! + + +9. Copyright +------------ + This driver is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; version 2 of the License. + If you want to use any later version of the GNU GPL, you will probably + be allowed to, but you have to ask me and Tekram <erich@tekram.com.tw> + before. + +------------------------------------------------------------------------- +Written by Kurt Garloff <kurt@garloff.de> 1998/06/11 +Last updated 2000/11/28, driver revision 2.0e7 +$Id: README.tmscsim,v 2.25.2.7 2000/12/20 01:07:12 garloff Exp $ |
