wikiATA exception Emask
ATA exception Emask notifications of the Linux kernel can indicate different errors. This article provides an overview of what kind of errors these could be.
SATA exception
A SATA excerption line contains the following areas:
| area | area |
|---|---|
| Emask | bit mask for error qualification (AC_ERR_xxx in source code) |
| SAct | SATA SActive Register (bei Native Command Queuing). The SActive-directory is used to track the completion status of commands in the queue. This directory is part of the Serial-ATA-specification defined tax-, state- and error-superset-directory.[1][2] |
| SErr | SATA SError Register |
| action | ATA_EH_xxx-actions, such as revalidate, softreset, hardreset (see include/linux/libata.h) |
| frozen | If present, indicates that the connection for SATA error handling (EH) has been frozen. |
Emask
The Emask Hex-values have the following meaning: [3]
| individual bits | byte (in Hex) | meaning | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Emask | details | ||
| AC_ERR_OK | 0x0 | no error | example: SATA exception Emask 0x0 SAct 0x80 SErr 0x0 action 0x6 frozen | ||||||||||
| 1 | AC_ERR_DEV | 0x1 | device error | Hardware indicates an error with last command. This error is delivered directly from the ATA device. If you see a lot of these, that is often an indication of a hardware problem. | |||||||||
| 1 | AC_ERR_HSM | 0x2 | HSM violation | Hardware failed to respond in an expected manner. "HSM" stands for Host State Machine, a software-based finite state machine required by ATA that expects certain hardware behaviors, based on the current ATA command and other hardware-state programming details. | |||||||||
| 1 | AC_ERR_TIMEOUT | 0x4 | Timeout | Controller failed to respond to an active ATA command. This could be any number of causes. Most often this is due to an unrelated interrupt subsystem bug (try booting with 'pci=nomsi' or 'acpi=off' or 'noapic'), which failed to deliver an interrupt when we were expecting one from the hardware. | |||||||||
| 1 | AC_ERR_MEDIA | 0x8 | Media Error | Software detected a media error | |||||||||
| 1 | AC_ERR_HOST_BUS | 0x10 | ATA Bus Error | chip<->device bus error
example: SATA exception Emask 0x10 SAct 0x0 SErr 0x4000000 action 0xe frozen | |||||||||
| 1 | AC_ERR_SYSTEM | 0x20 | Host Bus Error | Host<->chip bus error (i.e. PCI, if on PCI bus) | |||||||||
| 1 | AC_ERR_INVALID | 0x40 | System Error / Internal Error | Hardware flagged an impossible condition, most likely due to software misprogramming. | |||||||||
| 1 | AC_ERR_OTHER | 0x80 | Invalid Argument | Software marked ATA command as invalid, for some reason | |||||||||
| 1 | AC_ERR_NODEV_HINT | 0x100 | Unknown | Uncategorized error (should never happen) | |||||||||
| 1 | AC_ERR_NCQ | 0x200? | Polling Device Detection Hint | ||||||||||
Extract from the Linux kernel clude/linux/libata.h):[4]
enum ata_completion_errors {
AC_ERR_OK = 0, /* no error */
AC_ERR_DEV = (1 << 0), /* device reported error */
AC_ERR_HSM = (1 << 1), /* host state machine violation */
AC_ERR_TIMEOUT = (1 << 2), /* timeout */
AC_ERR_MEDIA = (1 << 3), /* media error */
AC_ERR_ATA_BUS = (1 << 4), /* ATA bus error */
AC_ERR_HOST_BUS = (1 << 5), /* host bus error */
AC_ERR_SYSTEM = (1 << 6), /* system error */
AC_ERR_INVALID = (1 << 7), /* invalid argument */
AC_ERR_OTHER = (1 << 8), /* unknown */
AC_ERR_NODEV_HINT = (1 << 9), /* polling device detection hint */
AC_ERR_NCQ = (1 << 10), /* marker for offending NCQ qc */
action
The action Hex-values have the following meaning:
| individual bits | byte (in Hex) | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | ||
| 1 | ATA_EH_REVALIDATE | 0x1 | |||||||||
| 1 | ATA_EH_SOFTRESET | 0x2 | |||||||||
| 1 | ATA_EH_HARDRESET | 0x4 | |||||||||
| 1 | ATA_EH_ENABLE_LINK | 0x8 | |||||||||
| 1 | ATA_EH_PARK | 0x20 | |||||||||
Extract from the Linux Kernel (include/linux/libata.h):[5]
/* reset / recovery action types */ ATA_EH_REVALIDATE = (1 << 0), ATA_EH_SOFTRESET = (1 << 1), /* meaningful only in ->prereset */ ATA_EH_HARDRESET = (1 << 2), /* meaningful only in ->prereset */ ATA_EH_RESET = ATA_EH_SOFTRESET | ATA_EH_HARDRESET, ATA_EH_ENABLE_LINK = (1 << 3), ATA_EH_PARK = (1 << 5), /* unload heads and stop I/O */ ATA_EH_PERDEV_MASK = ATA_EH_REVALIDATE | ATA_EH_PARK, ATA_EH_ALL_ACTIONS = ATA_EH_REVALIDATE | ATA_EH_RESET | ATA_EH_ENABLE_LINK,
References
- ↑ Serial ATA II Native Command Queuing Overview (www.intel.com, April 2003)
- ↑ Serial ATA Native Command Queuing (www.seagate.com, Juli 2003)
- ↑ Libata error messages - Error classes (ata.wiki.kernel.org)
- ↑ include/linux/libata.h - Kernel 6.2 - line 443 (git.kernel.org)
- ↑ include/linux/libata.h - Kernel 6.2 - line 303 (git.kernel.org)
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Author: Werner Fischer Werner Fischer, working in the Knowledge Transfer team at Thomas-Krenn, completed his studies of Computer and Media Security at FH Hagenberg in Austria. He is a regular speaker at many conferences like LinuxTag, OSMC, OSDC, LinuxCon, and author for various IT magazines. In his spare time he enjoys playing the piano and training for a good result at the annual Linz marathon relay.
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Translator: Alina Ranzinger Alina has been working at Thomas-Krenn.AG since 2024. After her training as multilingual business assistant, she got her job as assistant of the Product Management and is responsible for the translation of texts and for the organisation of the department.
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