diff options
Diffstat (limited to 'Documentation/ide')
| -rw-r--r-- | Documentation/ide/ChangeLog.ide-cd.1994-2004 | 268 | ||||
| -rw-r--r-- | Documentation/ide/ChangeLog.ide-floppy.1996-2002 | 63 | ||||
| -rw-r--r-- | Documentation/ide/ChangeLog.ide-tape.1995-2002 | 257 | ||||
| -rw-r--r-- | Documentation/ide/ide-tape.txt | 146 |
4 files changed, 734 insertions, 0 deletions
diff --git a/Documentation/ide/ChangeLog.ide-cd.1994-2004 b/Documentation/ide/ChangeLog.ide-cd.1994-2004 new file mode 100644 index 000000000000..190d17bfff62 --- /dev/null +++ b/Documentation/ide/ChangeLog.ide-cd.1994-2004 @@ -0,0 +1,268 @@ +/* + * 1.00 Oct 31, 1994 -- Initial version. + * 1.01 Nov 2, 1994 -- Fixed problem with starting request in + * cdrom_check_status. + * 1.03 Nov 25, 1994 -- leaving unmask_intr[] as a user-setting (as for disks) + * (from mlord) -- minor changes to cdrom_setup() + * -- renamed ide_dev_s to ide_drive_t, enable irq on command + * 2.00 Nov 27, 1994 -- Generalize packet command interface; + * add audio ioctls. + * 2.01 Dec 3, 1994 -- Rework packet command interface to handle devices + * which send an interrupt when ready for a command. + * 2.02 Dec 11, 1994 -- Cache the TOC in the driver. + * Don't use SCMD_PLAYAUDIO_TI; it's not included + * in the current version of ATAPI. + * Try to use LBA instead of track or MSF addressing + * when possible. + * Don't wait for READY_STAT. + * 2.03 Jan 10, 1995 -- Rewrite block read routines to handle block sizes + * other than 2k and to move multiple sectors in a + * single transaction. + * 2.04 Apr 21, 1995 -- Add work-around for Creative Labs CD220E drives. + * Thanks to Nick Saw <cwsaw@pts7.pts.mot.com> for + * help in figuring this out. Ditto for Acer and + * Aztech drives, which seem to have the same problem. + * 2.04b May 30, 1995 -- Fix to match changes in ide.c version 3.16 -ml + * 2.05 Jun 8, 1995 -- Don't attempt to retry after an illegal request + * or data protect error. + * Use HWIF and DEV_HWIF macros as in ide.c. + * Always try to do a request_sense after + * a failed command. + * Include an option to give textual descriptions + * of ATAPI errors. + * Fix a bug in handling the sector cache which + * showed up if the drive returned data in 512 byte + * blocks (like Pioneer drives). Thanks to + * Richard Hirst <srh@gpt.co.uk> for diagnosing this. + * Properly supply the page number field in the + * MODE_SELECT command. + * PLAYAUDIO12 is broken on the Aztech; work around it. + * 2.05x Aug 11, 1995 -- lots of data structure renaming/restructuring in ide.c + * (my apologies to Scott, but now ide-cd.c is independent) + * 3.00 Aug 22, 1995 -- Implement CDROMMULTISESSION ioctl. + * Implement CDROMREADAUDIO ioctl (UNTESTED). + * Use input_ide_data() and output_ide_data(). + * Add door locking. + * Fix usage count leak in cdrom_open, which happened + * when a read-write mount was attempted. + * Try to load the disk on open. + * Implement CDROMEJECT_SW ioctl (off by default). + * Read total cdrom capacity during open. + * Rearrange logic in cdrom_decode_status. Issue + * request sense commands for failed packet commands + * from here instead of from cdrom_queue_packet_command. + * Fix a race condition in retrieving error information. + * Suppress printing normal unit attention errors and + * some drive not ready errors. + * Implement CDROMVOLREAD ioctl. + * Implement CDROMREADMODE1/2 ioctls. + * Fix race condition in setting up interrupt handlers + * when the `serialize' option is used. + * 3.01 Sep 2, 1995 -- Fix ordering of reenabling interrupts in + * cdrom_queue_request. + * Another try at using ide_[input,output]_data. + * 3.02 Sep 16, 1995 -- Stick total disk capacity in partition table as well. + * Make VERBOSE_IDE_CD_ERRORS dump failed command again. + * Dump out more information for ILLEGAL REQUEST errs. + * Fix handling of errors occurring before the + * packet command is transferred. + * Fix transfers with odd bytelengths. + * 3.03 Oct 27, 1995 -- Some Creative drives have an id of just `CD'. + * `DCI-2S10' drives are broken too. + * 3.04 Nov 20, 1995 -- So are Vertos drives. + * 3.05 Dec 1, 1995 -- Changes to go with overhaul of ide.c and ide-tape.c + * 3.06 Dec 16, 1995 -- Add support needed for partitions. + * More workarounds for Vertos bugs (based on patches + * from Holger Dietze <dietze@aix520.informatik.uni-leipzig.de>). + * Try to eliminate byteorder assumptions. + * Use atapi_cdrom_subchnl struct definition. + * Add STANDARD_ATAPI compilation option. + * 3.07 Jan 29, 1996 -- More twiddling for broken drives: Sony 55D, + * Vertos 300. + * Add NO_DOOR_LOCKING configuration option. + * Handle drive_cmd requests w/NULL args (for hdparm -t). + * Work around sporadic Sony55e audio play problem. + * 3.07a Feb 11, 1996 -- check drive->id for NULL before dereferencing, to fix + * problem with "hde=cdrom" with no drive present. -ml + * 3.08 Mar 6, 1996 -- More Vertos workarounds. + * 3.09 Apr 5, 1996 -- Add CDROMCLOSETRAY ioctl. + * Switch to using MSF addressing for audio commands. + * Reformat to match kernel tabbing style. + * Add CDROM_GET_UPC ioctl. + * 3.10 Apr 10, 1996 -- Fix compilation error with STANDARD_ATAPI. + * 3.11 Apr 29, 1996 -- Patch from Heiko Eißfeldt <heiko@colossus.escape.de> + * to remove redundant verify_area calls. + * 3.12 May 7, 1996 -- Rudimentary changer support. Based on patches + * from Gerhard Zuber <zuber@berlin.snafu.de>. + * Let open succeed even if there's no loaded disc. + * 3.13 May 19, 1996 -- Fixes for changer code. + * 3.14 May 29, 1996 -- Add work-around for Vertos 600. + * (From Hennus Bergman <hennus@sky.ow.nl>.) + * 3.15 July 2, 1996 -- Added support for Sanyo 3 CD changers + * from Ben Galliart <bgallia@luc.edu> with + * special help from Jeff Lightfoot + * <jeffml@pobox.com> + * 3.15a July 9, 1996 -- Improved Sanyo 3 CD changer identification + * 3.16 Jul 28, 1996 -- Fix from Gadi to reduce kernel stack usage for ioctl. + * 3.17 Sep 17, 1996 -- Tweak audio reads for some drives. + * Start changing CDROMLOADFROMSLOT to CDROM_SELECT_DISC. + * 3.18 Oct 31, 1996 -- Added module and DMA support. + * + * 4.00 Nov 5, 1996 -- New ide-cd maintainer, + * Erik B. Andersen <andersee@debian.org> + * -- Newer Creative drives don't always set the error + * register correctly. Make sure we see media changes + * regardless. + * -- Integrate with generic cdrom driver. + * -- CDROMGETSPINDOWN and CDROMSETSPINDOWN ioctls, based on + * a patch from Ciro Cattuto <>. + * -- Call set_device_ro. + * -- Implement CDROMMECHANISMSTATUS and CDROMSLOTTABLE + * ioctls, based on patch by Erik Andersen + * -- Add some probes of drive capability during setup. + * + * 4.01 Nov 11, 1996 -- Split into ide-cd.c and ide-cd.h + * -- Removed CDROMMECHANISMSTATUS and CDROMSLOTTABLE + * ioctls in favor of a generalized approach + * using the generic cdrom driver. + * -- Fully integrated with the 2.1.X kernel. + * -- Other stuff that I forgot (lots of changes) + * + * 4.02 Dec 01, 1996 -- Applied patch from Gadi Oxman <gadio@netvision.net.il> + * to fix the drive door locking problems. + * + * 4.03 Dec 04, 1996 -- Added DSC overlap support. + * 4.04 Dec 29, 1996 -- Added CDROMREADRAW ioclt based on patch + * by Ales Makarov (xmakarov@sun.felk.cvut.cz) + * + * 4.05 Nov 20, 1997 -- Modified to print more drive info on init + * Minor other changes + * Fix errors on CDROMSTOP (If you have a "Dolphin", + * you must define IHAVEADOLPHIN) + * Added identifier so new Sanyo CD-changer works + * Better detection if door locking isn't supported + * + * 4.06 Dec 17, 1997 -- fixed endless "tray open" messages -ml + * 4.07 Dec 17, 1997 -- fallback to set pc->stat on "tray open" + * 4.08 Dec 18, 1997 -- spew less noise when tray is empty + * -- fix speed display for ACER 24X, 18X + * 4.09 Jan 04, 1998 -- fix handling of the last block so we return + * an end of file instead of an I/O error (Gadi) + * 4.10 Jan 24, 1998 -- fixed a bug so now changers can change to a new + * slot when there is no disc in the current slot. + * -- Fixed a memory leak where info->changer_info was + * malloc'ed but never free'd when closing the device. + * -- Cleaned up the global namespace a bit by making more + * functions static that should already have been. + * 4.11 Mar 12, 1998 -- Added support for the CDROM_SELECT_SPEED ioctl + * based on a patch for 2.0.33 by Jelle Foks + * <jelle@scintilla.utwente.nl>, a patch for 2.0.33 + * by Toni Giorgino <toni@pcape2.pi.infn.it>, the SCSI + * version, and my own efforts. -erik + * -- Fixed a stupid bug which egcs was kind enough to + * inform me of where "Illegal mode for this track" + * was never returned due to a comparison on data + * types of limited range. + * 4.12 Mar 29, 1998 -- Fixed bug in CDROM_SELECT_SPEED so write speed is + * now set ionly for CD-R and CD-RW drives. I had + * removed this support because it produced errors. + * It produced errors _only_ for non-writers. duh. + * 4.13 May 05, 1998 -- Suppress useless "in progress of becoming ready" + * messages, since this is not an error. + * -- Change error messages to be const + * -- Remove a "\t" which looks ugly in the syslogs + * 4.14 July 17, 1998 -- Change to pointing to .ps version of ATAPI spec + * since the .pdf version doesn't seem to work... + * -- Updated the TODO list to something more current. + * + * 4.15 Aug 25, 1998 -- Updated ide-cd.h to respect mechine endianess, + * patch thanks to "Eddie C. Dost" <ecd@skynet.be> + * + * 4.50 Oct 19, 1998 -- New maintainers! + * Jens Axboe <axboe@image.dk> + * Chris Zwilling <chris@cloudnet.com> + * + * 4.51 Dec 23, 1998 -- Jens Axboe <axboe@image.dk> + * - ide_cdrom_reset enabled since the ide subsystem + * handles resets fine now. <axboe@image.dk> + * - Transfer size fix for Samsung CD-ROMs, thanks to + * "Ville Hallik" <ville.hallik@mail.ee>. + * - other minor stuff. + * + * 4.52 Jan 19, 1999 -- Jens Axboe <axboe@image.dk> + * - Detect DVD-ROM/RAM drives + * + * 4.53 Feb 22, 1999 - Include other model Samsung and one Goldstar + * drive in transfer size limit. + * - Fix the I/O error when doing eject without a medium + * loaded on some drives. + * - CDROMREADMODE2 is now implemented through + * CDROMREADRAW, since many drives don't support + * MODE2 (even though ATAPI 2.6 says they must). + * - Added ignore parameter to ide-cd (as a module), eg + * insmod ide-cd ignore='hda hdb' + * Useful when using ide-cd in conjunction with + * ide-scsi. TODO: non-modular way of doing the + * same. + * + * 4.54 Aug 5, 1999 - Support for MMC2 class commands through the generic + * packet interface to cdrom.c. + * - Unified audio ioctl support, most of it. + * - cleaned up various deprecated verify_area(). + * - Added ide_cdrom_packet() as the interface for + * the Uniform generic_packet(). + * - bunch of other stuff, will fill in logs later. + * - report 1 slot for non-changers, like the other + * cd-rom drivers. don't report select disc for + * non-changers as well. + * - mask out audio playing, if the device can't do it. + * + * 4.55 Sep 1, 1999 - Eliminated the rest of the audio ioctls, except + * for CDROMREADTOC[ENTRY|HEADER]. Some of the drivers + * use this independently of the actual audio handling. + * They will disappear later when I get the time to + * do it cleanly. + * - Minimize the TOC reading - only do it when we + * know a media change has occurred. + * - Moved all the CDROMREADx ioctls to the Uniform layer. + * - Heiko Eißfeldt <heiko@colossus.escape.de> supplied + * some fixes for CDI. + * - CD-ROM leaving door locked fix from Andries + * Brouwer <Andries.Brouwer@cwi.nl> + * - Erik Andersen <andersen@xmission.com> unified + * commands across the various drivers and how + * sense errors are handled. + * + * 4.56 Sep 12, 1999 - Removed changer support - it is now in the + * Uniform layer. + * - Added partition based multisession handling. + * - Mode sense and mode select moved to the + * Uniform layer. + * - Fixed a problem with WPI CDS-32X drive - it + * failed the capabilities + * + * 4.57 Apr 7, 2000 - Fixed sense reporting. + * - Fixed possible oops in ide_cdrom_get_last_session() + * - Fix locking mania and make ide_cdrom_reset relock + * - Stop spewing errors to log when magicdev polls with + * TEST_UNIT_READY on some drives. + * - Various fixes from Tobias Ringstrom: + * tray if it was locked prior to the reset. + * - cdrom_read_capacity returns one frame too little. + * - Fix real capacity reporting. + * + * 4.58 May 1, 2000 - Clean up ACER50 stuff. + * - Fix small problem with ide_cdrom_capacity + * + * 4.59 Aug 11, 2000 - Fix changer problem in cdrom_read_toc, we weren't + * correctly sensing a disc change. + * - Rearranged some code + * - Use extended sense on drives that support it for + * correctly reporting tray status -- from + * Michael D Johnson <johnsom@orst.edu> + * 4.60 Dec 17, 2003 - Add mt rainier support + * - Bump timeout for packet commands, matches sr + * - Odd stuff + * 4.61 Jan 22, 2004 - support hardware sector sizes other than 2kB, + * Pascal Schmidt <der.eremit@email.de> + */ diff --git a/Documentation/ide/ChangeLog.ide-floppy.1996-2002 b/Documentation/ide/ChangeLog.ide-floppy.1996-2002 new file mode 100644 index 000000000000..46c19ef32a9e --- /dev/null +++ b/Documentation/ide/ChangeLog.ide-floppy.1996-2002 @@ -0,0 +1,63 @@ +/* + * Many thanks to Lode Leroy <Lode.Leroy@www.ibase.be>, who tested so many + * ALPHA patches to this driver on an EASYSTOR LS-120 ATAPI floppy drive. + * + * Ver 0.1 Oct 17 96 Initial test version, mostly based on ide-tape.c. + * Ver 0.2 Oct 31 96 Minor changes. + * Ver 0.3 Dec 2 96 Fixed error recovery bug. + * Ver 0.4 Jan 26 97 Add support for the HDIO_GETGEO ioctl. + * Ver 0.5 Feb 21 97 Add partitions support. + * Use the minimum of the LBA and CHS capacities. + * Avoid hwgroup->rq == NULL on the last irq. + * Fix potential null dereferencing with DEBUG_LOG. + * Ver 0.8 Dec 7 97 Increase irq timeout from 10 to 50 seconds. + * Add media write-protect detection. + * Issue START command only if TEST UNIT READY fails. + * Add work-around for IOMEGA ZIP revision 21.D. + * Remove idefloppy_get_capabilities(). + * Ver 0.9 Jul 4 99 Fix a bug which might have caused the number of + * bytes requested on each interrupt to be zero. + * Thanks to <shanos@es.co.nz> for pointing this out. + * Ver 0.9.sv Jan 6 01 Sam Varshavchik <mrsam@courier-mta.com> + * Implement low level formatting. Reimplemented + * IDEFLOPPY_CAPABILITIES_PAGE, since we need the srfp + * bit. My LS-120 drive barfs on + * IDEFLOPPY_CAPABILITIES_PAGE, but maybe it's just me. + * Compromise by not reporting a failure to get this + * mode page. Implemented four IOCTLs in order to + * implement formatting. IOCTls begin with 0x4600, + * 0x46 is 'F' as in Format. + * Jan 9 01 Userland option to select format verify. + * Added PC_SUPPRESS_ERROR flag - some idefloppy drives + * do not implement IDEFLOPPY_CAPABILITIES_PAGE, and + * return a sense error. Suppress error reporting in + * this particular case in order to avoid spurious + * errors in syslog. The culprit is + * idefloppy_get_capability_page(), so move it to + * idefloppy_begin_format() so that it's not used + * unless absolutely necessary. + * If drive does not support format progress indication + * monitor the dsc bit in the status register. + * Also, O_NDELAY on open will allow the device to be + * opened without a disk available. This can be used to + * open an unformatted disk, or get the device capacity. + * Ver 0.91 Dec 11 99 Added IOMEGA Clik! drive support by + * <paul@paulbristow.net> + * Ver 0.92 Oct 22 00 Paul Bristow became official maintainer for this + * driver. Included Powerbook internal zip kludge. + * Ver 0.93 Oct 24 00 Fixed bugs for Clik! drive + * no disk on insert and disk change now works + * Ver 0.94 Oct 27 00 Tidied up to remove strstr(Clik) everywhere + * Ver 0.95 Nov 7 00 Brought across to kernel 2.4 + * Ver 0.96 Jan 7 01 Actually in line with release version of 2.4.0 + * including set_bit patch from Rusty Russell + * Ver 0.97 Jul 22 01 Merge 0.91-0.96 onto 0.9.sv for ac series + * Ver 0.97.sv Aug 3 01 Backported from 2.4.7-ac3 + * Ver 0.98 Oct 26 01 Split idefloppy_transfer_pc into two pieces to + * fix a lost interrupt problem. It appears the busy + * bit was being deasserted by my IOMEGA ATAPI ZIP 100 + * drive before the drive was actually ready. + * Ver 0.98a Oct 29 01 Expose delay value so we can play. + * Ver 0.99 Feb 24 02 Remove duplicate code, modify clik! detection code + * to support new PocketZip drives + */ diff --git a/Documentation/ide/ChangeLog.ide-tape.1995-2002 b/Documentation/ide/ChangeLog.ide-tape.1995-2002 new file mode 100644 index 000000000000..877fac8770b3 --- /dev/null +++ b/Documentation/ide/ChangeLog.ide-tape.1995-2002 @@ -0,0 +1,257 @@ +/* + * Ver 0.1 Nov 1 95 Pre-working code :-) + * Ver 0.2 Nov 23 95 A short backup (few megabytes) and restore procedure + * was successful ! (Using tar cvf ... on the block + * device interface). + * A longer backup resulted in major swapping, bad + * overall Linux performance and eventually failed as + * we received non serial read-ahead requests from the + * buffer cache. + * Ver 0.3 Nov 28 95 Long backups are now possible, thanks to the + * character device interface. Linux's responsiveness + * and performance doesn't seem to be much affected + * from the background backup procedure. + * Some general mtio.h magnetic tape operations are + * now supported by our character device. As a result, + * popular tape utilities are starting to work with + * ide tapes :-) + * The following configurations were tested: + * 1. An IDE ATAPI TAPE shares the same interface + * and irq with an IDE ATAPI CDROM. + * 2. An IDE ATAPI TAPE shares the same interface + * and irq with a normal IDE disk. + * Both configurations seemed to work just fine ! + * However, to be on the safe side, it is meanwhile + * recommended to give the IDE TAPE its own interface + * and irq. + * The one thing which needs to be done here is to + * add a "request postpone" feature to ide.c, + * so that we won't have to wait for the tape to finish + * performing a long media access (DSC) request (such + * as a rewind) before we can access the other device + * on the same interface. This effect doesn't disturb + * normal operation most of the time because read/write + * requests are relatively fast, and once we are + * performing one tape r/w request, a lot of requests + * from the other device can be queued and ide.c will + * service all of them after this single tape request. + * Ver 1.0 Dec 11 95 Integrated into Linux 1.3.46 development tree. + * On each read / write request, we now ask the drive + * if we can transfer a constant number of bytes + * (a parameter of the drive) only to its buffers, + * without causing actual media access. If we can't, + * we just wait until we can by polling the DSC bit. + * This ensures that while we are not transferring + * more bytes than the constant referred to above, the + * interrupt latency will not become too high and + * we won't cause an interrupt timeout, as happened + * occasionally in the previous version. + * While polling for DSC, the current request is + * postponed and ide.c is free to handle requests from + * the other device. This is handled transparently to + * ide.c. The hwgroup locking method which was used + * in the previous version was removed. + * Use of new general features which are provided by + * ide.c for use with atapi devices. + * (Programming done by Mark Lord) + * Few potential bug fixes (Again, suggested by Mark) + * Single character device data transfers are now + * not limited in size, as they were before. + * We are asking the tape about its recommended + * transfer unit and send a larger data transfer + * as several transfers of the above size. + * For best results, use an integral number of this + * basic unit (which is shown during driver + * initialization). I will soon add an ioctl to get + * this important parameter. + * Our data transfer buffer is allocated on startup, + * rather than before each data transfer. This should + * ensure that we will indeed have a data buffer. + * Ver 1.1 Dec 14 95 Fixed random problems which occurred when the tape + * shared an interface with another device. + * (poll_for_dsc was a complete mess). + * Removed some old (non-active) code which had + * to do with supporting buffer cache originated + * requests. + * The block device interface can now be opened, so + * that general ide driver features like the unmask + * interrupts flag can be selected with an ioctl. + * This is the only use of the block device interface. + * New fast pipelined operation mode (currently only on + * writes). When using the pipelined mode, the + * throughput can potentially reach the maximum + * tape supported throughput, regardless of the + * user backup program. On my tape drive, it sometimes + * boosted performance by a factor of 2. Pipelined + * mode is enabled by default, but since it has a few + * downfalls as well, you may want to disable it. + * A short explanation of the pipelined operation mode + * is available below. + * Ver 1.2 Jan 1 96 Eliminated pipelined mode race condition. + * Added pipeline read mode. As a result, restores + * are now as fast as backups. + * Optimized shared interface behavior. The new behavior + * typically results in better IDE bus efficiency and + * higher tape throughput. + * Pre-calculation of the expected read/write request + * service time, based on the tape's parameters. In + * the pipelined operation mode, this allows us to + * adjust our polling frequency to a much lower value, + * and thus to dramatically reduce our load on Linux, + * without any decrease in performance. + * Implemented additional mtio.h operations. + * The recommended user block size is returned by + * the MTIOCGET ioctl. + * Additional minor changes. + * Ver 1.3 Feb 9 96 Fixed pipelined read mode bug which prevented the + * use of some block sizes during a restore procedure. + * The character device interface will now present a + * continuous view of the media - any mix of block sizes + * during a backup/restore procedure is supported. The + * driver will buffer the requests internally and + * convert them to the tape's recommended transfer + * unit, making performance almost independent of the + * chosen user block size. + * Some improvements in error recovery. + * By cooperating with ide-dma.c, bus mastering DMA can + * now sometimes be used with IDE tape drives as well. + * Bus mastering DMA has the potential to dramatically + * reduce the CPU's overhead when accessing the device, + * and can be enabled by using hdparm -d1 on the tape's + * block device interface. For more info, read the + * comments in ide-dma.c. + * Ver 1.4 Mar 13 96 Fixed serialize support. + * Ver 1.5 Apr 12 96 Fixed shared interface operation, broken in 1.3.85. + * Fixed pipelined read mode inefficiency. + * Fixed nasty null dereferencing bug. + * Ver 1.6 Aug 16 96 Fixed FPU usage in the driver. + * Fixed end of media bug. + * Ver 1.7 Sep 10 96 Minor changes for the CONNER CTT8000-A model. + * Ver 1.8 Sep 26 96 Attempt to find a better balance between good + * interactive response and high system throughput. + * Ver 1.9 Nov 5 96 Automatically cross encountered filemarks rather + * than requiring an explicit FSF command. + * Abort pending requests at end of media. + * MTTELL was sometimes returning incorrect results. + * Return the real block size in the MTIOCGET ioctl. + * Some error recovery bug fixes. + * Ver 1.10 Nov 5 96 Major reorganization. + * Reduced CPU overhead a bit by eliminating internal + * bounce buffers. + * Added module support. + * Added multiple tape drives support. + * Added partition support. + * Rewrote DSC handling. + * Some portability fixes. + * Removed ide-tape.h. + * Additional minor changes. + * Ver 1.11 Dec 2 96 Bug fix in previous DSC timeout handling. + * Use ide_stall_queue() for DSC overlap. + * Use the maximum speed rather than the current speed + * to compute the request service time. + * Ver 1.12 Dec 7 97 Fix random memory overwriting and/or last block data + * corruption, which could occur if the total number + * of bytes written to the tape was not an integral + * number of tape blocks. + * Add support for INTERRUPT DRQ devices. + * Ver 1.13 Jan 2 98 Add "speed == 0" work-around for HP COLORADO 5GB + * Ver 1.14 Dec 30 98 Partial fixes for the Sony/AIWA tape drives. + * Replace cli()/sti() with hwgroup spinlocks. + * Ver 1.15 Mar 25 99 Fix SMP race condition by replacing hwgroup + * spinlock with private per-tape spinlock. + * Ver 1.16 Sep 1 99 Add OnStream tape support. + * Abort read pipeline on EOD. + * Wait for the tape to become ready in case it returns + * "in the process of becoming ready" on open(). + * Fix zero padding of the last written block in + * case the tape block size is larger than PAGE_SIZE. + * Decrease the default disconnection time to tn. + * Ver 1.16e Oct 3 99 Minor fixes. + * Ver 1.16e1 Oct 13 99 Patches by Arnold Niessen, + * niessen@iae.nl / arnold.niessen@philips.com + * GO-1) Undefined code in idetape_read_position + * according to Gadi's email + * AJN-1) Minor fix asc == 11 should be asc == 0x11 + * in idetape_issue_packet_command (did effect + * debugging output only) + * AJN-2) Added more debugging output, and + * added ide-tape: where missing. I would also + * like to add tape->name where possible + * AJN-3) Added different debug_level's + * via /proc/ide/hdc/settings + * "debug_level" determines amount of debugging output; + * can be changed using /proc/ide/hdx/settings + * 0 : almost no debugging output + * 1 : 0+output errors only + * 2 : 1+output all sensekey/asc + * 3 : 2+follow all chrdev related procedures + * 4 : 3+follow all procedures + * 5 : 4+include pc_stack rq_stack info + * 6 : 5+USE_COUNT updates + * AJN-4) Fixed timeout for retension in idetape_queue_pc_tail + * from 5 to 10 minutes + * AJN-5) Changed maximum number of blocks to skip when + * reading tapes with multiple consecutive write + * errors from 100 to 1000 in idetape_get_logical_blk + * Proposed changes to code: + * 1) output "logical_blk_num" via /proc + * 2) output "current_operation" via /proc + * 3) Either solve or document the fact that `mt rewind' is + * required after reading from /dev/nhtx to be + * able to rmmod the idetape module; + * Also, sometimes an application finishes but the + * device remains `busy' for some time. Same cause ? + * Proposed changes to release-notes: + * 4) write a simple `quickstart' section in the + * release notes; I volunteer if you don't want to + * 5) include a pointer to video4linux in the doc + * to stimulate video applications + * 6) release notes lines 331 and 362: explain what happens + * if the application data rate is higher than 1100 KB/s; + * similar approach to lower-than-500 kB/s ? + * 7) 6.6 Comparison; wouldn't it be better to allow different + * strategies for read and write ? + * Wouldn't it be better to control the tape buffer + * contents instead of the bandwidth ? + * 8) line 536: replace will by would (if I understand + * this section correctly, a hypothetical and unwanted situation + * is being described) + * Ver 1.16f Dec 15 99 Change place of the secondary OnStream header frames. + * Ver 1.17 Nov 2000 / Jan 2001 Marcel Mol, marcel@mesa.nl + * - Add idetape_onstream_mode_sense_tape_parameter_page + * function to get tape capacity in frames: tape->capacity. + * - Add support for DI-50 drives( or any DI- drive). + * - 'workaround' for read error/blank block around block 3000. + * - Implement Early warning for end of media for Onstream. + * - Cosmetic code changes for readability. + * - Idetape_position_tape should not use SKIP bit during + * Onstream read recovery. + * - Add capacity, logical_blk_num and first/last_frame_position + * to /proc/ide/hd?/settings. + * - Module use count was gone in the Linux 2.4 driver. + * Ver 1.17a Apr 2001 Willem Riede osst@riede.org + * - Get drive's actual block size from mode sense block descriptor + * - Limit size of pipeline + * Ver 1.17b Oct 2002 Alan Stern <stern@rowland.harvard.edu> + * Changed IDETAPE_MIN_PIPELINE_STAGES to 1 and actually used + * it in the code! + * Actually removed aborted stages in idetape_abort_pipeline + * instead of just changing the command code. + * Made the transfer byte count for Request Sense equal to the + * actual length of the data transfer. + * Changed handling of partial data transfers: they do not + * cause DMA errors. + * Moved initiation of DMA transfers to the correct place. + * Removed reference to unallocated memory. + * Made __idetape_discard_read_pipeline return the number of + * sectors skipped, not the number of stages. + * Replaced errant kfree() calls with __idetape_kfree_stage(). + * Fixed off-by-one error in testing the pipeline length. + * Fixed handling of filemarks in the read pipeline. + * Small code optimization for MTBSF and MTBSFM ioctls. + * Don't try to unlock the door during device close if is + * already unlocked! + * Cosmetic fixes to miscellaneous debugging output messages. + * Set the minimum /proc/ide/hd?/settings values for "pipeline", + * "pipeline_min", and "pipeline_max" to 1. + */ diff --git a/Documentation/ide/ide-tape.txt b/Documentation/ide/ide-tape.txt new file mode 100644 index 000000000000..658f271a373f --- /dev/null +++ b/Documentation/ide/ide-tape.txt @@ -0,0 +1,146 @@ +/* + * IDE ATAPI streaming tape driver. + * + * This driver is a part of the Linux ide driver. + * + * The driver, in co-operation with ide.c, basically traverses the + * request-list for the block device interface. The character device + * interface, on the other hand, creates new requests, adds them + * to the request-list of the block device, and waits for their completion. + * + * Pipelined operation mode is now supported on both reads and writes. + * + * The block device major and minor numbers are determined from the + * tape's relative position in the ide interfaces, as explained in ide.c. + * + * The character device interface consists of the following devices: + * + * ht0 major 37, minor 0 first IDE tape, rewind on close. + * ht1 major 37, minor 1 second IDE tape, rewind on close. + * ... + * nht0 major 37, minor 128 first IDE tape, no rewind on close. + * nht1 major 37, minor 129 second IDE tape, no rewind on close. + * ... + * + * The general magnetic tape commands compatible interface, as defined by + * include/linux/mtio.h, is accessible through the character device. + * + * General ide driver configuration options, such as the interrupt-unmask + * flag, can be configured by issuing an ioctl to the block device interface, + * as any other ide device. + * + * Our own ide-tape ioctl's can be issued to either the block device or + * the character device interface. + * + * Maximal throughput with minimal bus load will usually be achieved in the + * following scenario: + * + * 1. ide-tape is operating in the pipelined operation mode. + * 2. No buffering is performed by the user backup program. + * + * Testing was done with a 2 GB CONNER CTMA 4000 IDE ATAPI Streaming Tape Drive. + * + * Here are some words from the first releases of hd.c, which are quoted + * in ide.c and apply here as well: + * + * | Special care is recommended. Have Fun! + * + * + * An overview of the pipelined operation mode. + * + * In the pipelined write mode, we will usually just add requests to our + * pipeline and return immediately, before we even start to service them. The + * user program will then have enough time to prepare the next request while + * we are still busy servicing previous requests. In the pipelined read mode, + * the situation is similar - we add read-ahead requests into the pipeline, + * before the user even requested them. + * + * The pipeline can be viewed as a "safety net" which will be activated when + * the system load is high and prevents the user backup program from keeping up + * with the current tape speed. At this point, the pipeline will get + * shorter and shorter but the tape will still be streaming at the same speed. + * Assuming we have enough pipeline stages, the system load will hopefully + * decrease before the pipeline is completely empty, and the backup program + * will be able to "catch up" and refill the pipeline again. + * + * When using the pipelined mode, it would be best to disable any type of + * buffering done by the user program, as ide-tape already provides all the + * benefits in the kernel, where it can be done in a more efficient way. + * As we will usually not block the user program on a request, the most + * efficient user code will then be a simple read-write-read-... cycle. + * Any additional logic will usually just slow down the backup process. + * + * Using the pipelined mode, I get a constant over 400 KBps throughput, + * which seems to be the maximum throughput supported by my tape. + * + * However, there are some downfalls: + * + * 1. We use memory (for data buffers) in proportional to the number + * of pipeline stages (each stage is about 26 KB with my tape). + * 2. In the pipelined write mode, we cheat and postpone error codes + * to the user task. In read mode, the actual tape position + * will be a bit further than the last requested block. + * + * Concerning (1): + * + * 1. We allocate stages dynamically only when we need them. When + * we don't need them, we don't consume additional memory. In + * case we can't allocate stages, we just manage without them + * (at the expense of decreased throughput) so when Linux is + * tight in memory, we will not pose additional difficulties. + * + * 2. The maximum number of stages (which is, in fact, the maximum + * amount of memory) which we allocate is limited by the compile + * time parameter IDETAPE_MAX_PIPELINE_STAGES. + * + * 3. The maximum number of stages is a controlled parameter - We + * don't start from the user defined maximum number of stages + * but from the lower IDETAPE_MIN_PIPELINE_STAGES (again, we + * will not even allocate this amount of stages if the user + * program can't handle the speed). We then implement a feedback + * loop which checks if the pipeline is empty, and if it is, we + * increase the maximum number of stages as necessary until we + * reach the optimum value which just manages to keep the tape + * busy with minimum allocated memory or until we reach + * IDETAPE_MAX_PIPELINE_STAGES. + * + * Concerning (2): + * + * In pipelined write mode, ide-tape can not return accurate error codes + * to the user program since we usually just add the request to the + * pipeline without waiting for it to be serviced. In case an error + * occurs, I will report it on the next user request. + * + * In the pipelined read mode, subsequent read requests or forward + * filemark spacing will perform correctly, as we preserve all blocks + * and filemarks which we encountered during our excess read-ahead. + * + * For accurate tape positioning and error reporting, disabling + * pipelined mode might be the best option. + * + * You can enable/disable/tune the pipelined operation mode by adjusting + * the compile time parameters below. + * + * + * Possible improvements. + * + * 1. Support for the ATAPI overlap protocol. + * + * In order to maximize bus throughput, we currently use the DSC + * overlap method which enables ide.c to service requests from the + * other device while the tape is busy executing a command. The + * DSC overlap method involves polling the tape's status register + * for the DSC bit, and servicing the other device while the tape + * isn't ready. + * + * In the current QIC development standard (December 1995), + * it is recommended that new tape drives will *in addition* + * implement the ATAPI overlap protocol, which is used for the + * same purpose - efficient use of the IDE bus, but is interrupt + * driven and thus has much less CPU overhead. + * + * ATAPI overlap is likely to be supported in most new ATAPI + * devices, including new ATAPI cdroms, and thus provides us + * a method by which we can achieve higher throughput when + * sharing a (fast) ATA-2 disk with any (slow) new ATAPI device. + */ |