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Diffstat (limited to 'Documentation/ide/ChangeLog.ide-tape.1995-2002')
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diff --git a/Documentation/ide/ChangeLog.ide-tape.1995-2002 b/Documentation/ide/ChangeLog.ide-tape.1995-2002 deleted file mode 100644 index 877fac8770b3..000000000000 --- a/Documentation/ide/ChangeLog.ide-tape.1995-2002 +++ /dev/null @@ -1,257 +0,0 @@ -/* - * 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. - */ |