Documentation/driver-api/libata.rst

403 This chapter describes how errors are handled under libata. Readers are
580    Errors which aren't ATA device errors are treated as ATA device
581    errors by setting ATA_ERR bit. Better error descriptor which can
582    properly represent ATA and other errors/exceptions is needed.
593    errors and other errors quite often require reset to return to known
597 -  ATA errors are directly handled in the interrupt handler and PIO
598    errors in pio_task. This is problematic for advanced error handling
637 ATA errors and exceptions
648 which are not errors (say, power or hotplug events), or to describe both
649 errors and non-error exceptional conditions. Where explicit distinction
691 transmission errors sometimes cause this kind of errors.
696 These are errors detected and reported by ATA/ATAPI devices indicating
697 device problems. For this type of errors, STATUS and ERROR register
699 errors are detected by ATA/ATAPI devices and reported using the same
700 mechanism as device errors. Those cases are described later in this
703 For ATA commands, this type of errors are indicated by !BSY && ERR
718 Of errors detected as above, the following are not ATA/ATAPI device
719 errors but ATA bus errors and should be handled according to
731     ICRC errors and on cases where a device is not able to complete a
732     command. Combined with the fact that MWDMA and PIO transfer errors
734     that ABRT bit alone could indicate transfer errors.
737     errors can turn on ABRT. So, this is kind of gray area. Some
740 ATA/ATAPI device errors can be further categorized as follows.
742 Media errors
761 Other errors
764     of things including ICRC and Address errors. Heuristics needed.
784 PACKET command. For this kind of errors, sense data should be acquired
785 to gather information regarding the errors. REQUEST SENSE packet command
788 Once sense data is acquired, this type of errors can be handled
789 similarly to other SCSI errors. Note that sense data may indicate ATA
811 Note that ATA bus errors can be reported as ATA device NCQ errors. This
822 over ATA bus (SATA or PATA). This type of errors can be indicated by
833 -  Unknown/random errors, timeouts and all sorts of weirdities.
835 As described above, transmission errors can cause wide variety of
839 of heuristic when dealing with errors and timeouts. For example,
840 encountering repetitive ABRT errors for known supported command is
843 Once it's determined that ATA bus errors have possibly occurred,
853 BMDMA Status register. This type of errors must be logged as it
862 usually caused by lost interrupts. This type of errors must be logged.
874 Timeouts can also be caused by transmission errors. Refer to
998     If more than $N (3?) transmission errors happen in 15 minutes,