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ide-tape: remove comments markup from Documentation/ide/ide-tape.txt 

Signed-off-by: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
This commit is contained in:
Borislav Petkov 2008-04-27 15:38:28 +02:00 committed by Bartlomiej Zolnierkiewicz
parent 4735f22cc1
commit 10569713c7
1 changed files with 65 additions and 67 deletions
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132
Documentation/ide/ide-tape.txt
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@ -1,67 +1,65 @@
/* IDE ATAPI streaming tape driver.
* IDE ATAPI streaming tape driver.
* This driver is a part of the Linux ide driver.
* This driver is a part of the Linux ide driver.
* The driver, in co-operation with ide.c, basically traverses the
* The driver, in co-operation with ide.c, basically traverses the request-list for the block device interface. The character device
* request-list for the block device interface. The character device interface, on the other hand, creates new requests, adds them
* interface, on the other hand, creates new requests, adds them to the request-list of the block device, and waits for their completion.
* to the request-list of the block device, and waits for their completion.
* The block device major and minor numbers are determined from the
* The block device major and minor numbers are determined from the tape's relative position in the ide interfaces, as explained in ide.c.
* tape's relative position in the ide interfaces, as explained in ide.c.
* The character device interface consists of the following devices:
* The character device interface consists of the following devices:
* ht0 major 37, minor 0 first IDE tape, rewind on close.
* ht0 major 37, minor 0 first IDE tape, rewind on close. ht1 major 37, minor 1 second 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.
* nht0 major 37, minor 128 first IDE tape, no rewind on close. nht1 major 37, minor 129 second 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
* The general magnetic tape commands compatible interface, as defined by include/linux/mtio.h, is accessible through the character device.
* include/linux/mtio.h, is accessible through the character device.
* General ide driver configuration options, such as the interrupt-unmask
* General ide driver configuration options, such as the interrupt-unmask flag, can be configured by issuing an ioctl to the block device interface,
* flag, can be configured by issuing an ioctl to the block device interface, as any other ide device.
* as any other ide device.
* Our own ide-tape ioctl's can be issued to either the block device or
* Our own ide-tape ioctl's can be issued to either the block device or the character device interface.
* the character device interface.
* Maximal throughput with minimal bus load will usually be achieved in the
* Maximal throughput with minimal bus load will usually be achieved in the following scenario:
* following scenario:
* 1. ide-tape is operating in the pipelined operation mode.
* 1. ide-tape is operating in the pipelined operation mode. 2. No buffering is performed by the user backup program.
* 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.
* 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
* Here are some words from the first releases of hd.c, which are quoted in ide.c and apply here as well:
* in ide.c and apply here as well:
* | Special care is recommended. Have Fun!
* | Special care is recommended. Have Fun!
* Possible improvements:
* Possible improvements.
* 1. Support for the ATAPI overlap protocol.
* 1. Support for the ATAPI overlap protocol.
* In order to maximize bus throughput, we currently use the DSC
* In order to maximize bus throughput, we currently use the DSC overlap method which enables ide.c to service requests from the
* overlap method which enables ide.c to service requests from the other device while the tape is busy executing a command. The
* other device while the tape is busy executing a command. The DSC overlap method involves polling the tape's status register
* DSC overlap method involves polling the tape's status register for the DSC bit, and servicing the other device while the tape
* for the DSC bit, and servicing the other device while the tape isn't ready.
* isn't ready.
* In the current QIC development standard (December 1995),
* In the current QIC development standard (December 1995), it is recommended that new tape drives will *in addition*
* it is recommended that new tape drives will *in addition* implement the ATAPI overlap protocol, which is used for the
* implement the ATAPI overlap protocol, which is used for the same purpose - efficient use of the IDE bus, but is interrupt
* same purpose - efficient use of the IDE bus, but is interrupt driven and thus has much less CPU overhead.
* driven and thus has much less CPU overhead.
* ATAPI overlap is likely to be supported in most new ATAPI
* ATAPI overlap is likely to be supported in most new ATAPI devices, including new ATAPI cdroms, and thus provides us
* devices, including new ATAPI cdroms, and thus provides us a method by which we can achieve higher throughput when
* a method by which we can achieve higher throughput when sharing a (fast) ATA-2 disk with any (slow) new ATAPI device.
* sharing a (fast) ATA-2 disk with any (slow) new ATAPI device.
*/