libata: add command name parsing for error output

This patch improve libata's output for error/notification messages
to allow easier comprehension and debugging:

When ATAPI commands issued through the SCSI layer fail, use SCSI
functions to print the CDB in human-readable form instead of just
dumping out the CDB in hex.

Print out the name of the failed command (as defined by the ATA
specification) in error handling output along with the raw register
contents.

When reporting status of ACPI taskfile commands executed on resume,
also output the names of the commands being executed (or not) in
readable form.

Since the extra data for printing command names increases kernel
size slightly, a config option has been added to allow disabling
command name output (as well as some of the error register parsing)
for those highly sensitive to kernel text size.

Signed-off-by: Robert Hancock <hancockrwd@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/ata/Kconfig b/drivers/ata/Kconfig
index b17c57f8503..8e64d3c81d5 100644
--- a/drivers/ata/Kconfig
+++ b/drivers/ata/Kconfig
@@ -26,6 +26,17 @@ config ATA_NONSTANDARD
        bool
        default n
 
+config ATA_VERBOSE_ERROR
+        bool "Verbose ATA error reporting"
+        default y
+        help
+          This option adds parsing of ATA command descriptions and error bits
+          in libata kernel output, making it easier to interpret.
+          This option will enlarge the kernel by approx. 6KB. Disable it only
+          if kernel size is more important than ease of debugging.
+
+          If unsure, say Y.
+
 config ATA_ACPI
         bool "ATA ACPI Support"
         depends on ACPI && PCI