Documentation/driver-api/libata.rst

10 libATA is a library used inside the Linux kernel to support ATA host
11 controllers and devices. libATA provides an ATA driver API, class
12 transports for ATA and ATAPI devices, and SCSI<->ATA translation for ATA
16 internals, and a couple sample ATA low-level drivers.
24 with the ATA and SCSI layers.
29 defining at a bare minimum the bus I/O addresses of the ATA shadow
107 ATA command execute
115 causes an ATA command, previously loaded with ``->tf_load()``, to be
127 Allow low-level driver to filter ATA PACKET commands, returning a status
134 Read specific ATA shadow registers
143 Reads the Status/AltStatus ATA shadow register from hardware. On some
148 Write specific ATA shadow register
156 Write the device control ATA shadow register to the hardware. Most
159 Select ATA device on bus
169 the ATA bus. This generally has no meaning on FIS-based devices.
183 with the ATA timing rules and also applies blacklists and cable limits.
185 typically raid controllers that use ATA commands but do not actually do
379 advised to read SCSI EH (Documentation/scsi/scsi_eh.rst) and ATA
419     ``qc->complete_fn()`` callback is used for completion notification. ATA
435 Currently 6 ATA command protocols are used. They can be sorted into the
438 ATA NO DATA or DMA
443 ATA PIO
542    conditions are represented with ATA STATUS and ERROR registers.
543    Errors which aren't ATA device errors are treated as ATA device
545    properly represent ATA and other errors/exceptions is needed.
560 -  ATA errors are directly handled in the interrupt handler and PIO
600 ATA errors and exceptions
604 ATA/ATAPI devices and describe how they should be handled in
632 during issuing or execution any ATA/ATAPI command.
642    is transferred. ATA/ATAPI standard states that "The device shall not
656 ATA/ATAPI device error (non-NCQ / non-CHECK CONDITION)
659 These are errors detected and reported by ATA/ATAPI devices indicating
661 values are valid and describe error condition. Note that some of ATA bus
662 errors are detected by ATA/ATAPI devices and reported using the same
666 For ATA commands, this type of errors are indicated by !BSY && ERR
681 Of errors detected as above, the following are not ATA/ATAPI device
682 errors but ATA bus errors and should be handled according to
683 `ATA bus error <#excatATAbusErr>`__.
687     corruption occurred during data transfer. Up to ATA/ATAPI-7, the
689     transfers but ATA/ATAPI-8 draft revision 1f says that the bit may be
693     Up to ATA/ATAPI-7, the standard specifies that ABRT could be set on
696     aren't allowed to use ICRC bit up to ATA/ATAPI-7, it seems to imply
699     However, ATA/ATAPI-8 draft revision 1f removes the part that ICRC
703 ATA/ATAPI device errors can be further categorized as follows.
706     This is indicated by UNC bit in the ERROR register. ATA devices
712     but ATA/ATAPI standard specifies that the amount of transferred data
731 up to ATA/ATAPI-7 no definition of "na" can be found. However,
732 ATA/ATAPI-8 draft revision 1f describes "N/A" as follows.
752 similarly to other SCSI errors. Note that sense data may indicate ATA
754 PARITY ERROR). In such cases, the error should be considered as an ATA
755 bus error and handled according to `ATA bus error <#excatATAbusErr>`__.
757 ATA device error (NCQ)
768 command can be handled as a normal ATA command error as in
769 `ATA/ATAPI device error (non-NCQ / non-CHECK CONDITION) <#excatDevErr>`__
774 Note that ATA bus errors can be reported as ATA device NCQ errors. This
775 should be handled as described in `ATA bus error <#excatATAbusErr>`__.
781 ATA bus error
784 ATA bus error means that data corruption occurred during transmission
785 over ATA bus (SATA or PATA). This type of errors can be indicated by
788    `ATA/ATAPI device error (non-NCQ / non-CHECK CONDITION) <#excatDevErr>`__.
804 likely to indicate ATA bus error.
806 Once it's determined that ATA bus errors have possibly occurred,
807 lowering ATA bus transmission speed is one of actions which may
838 `ATA bus error <#excatATAbusErr>`__ for more details.
876 -  When it's known that HBA is in ready state but ATA/ATAPI device is in
888 OTOH, ATA/ATAPI standard describes in detail ways to reset ATA/ATAPI
905     Although ATA/ATAPI standard doesn't describe exactly, EDD implies
941 ATA/ATAPI standard specifies that some parameters must be maintained
947 Also, ATA/ATAPI standard requires that IDENTIFY DEVICE / IDENTIFY PACKET
984 The bulk of the ATA knowledge comes thanks to long conversations with
985 Andre Hedrick (www.linux-ide.org), and long hours pondering the ATA and