Add a function to check an ATA device's id for head unload support as
specified in ATA-7.
Signed-off-by: Elias Oltmanns <eo@xxxxxxxxxxxxxx>
---
include/linux/ata.h | 17 +++++++++++++++++
1 files changed, 17 insertions(+), 0 deletions(-)
diff --git a/include/linux/ata.h b/include/linux/ata.h
index 80364b6..d9a94bd 100644
--- a/include/linux/ata.h
+++ b/include/linux/ata.h
@@ -707,6 +707,23 @@ static inline int ata_id_has_dword_io(const u16 *id)
return 0;
}
+static inline int ata_id_has_unload(const u16 *id)
+{
+ /*
+ * ATA-7 specifies two places to indicate unload feature
+ * support. Since I don't really understand the difference,
+ * I'll just check both and only return zero if none of them
+ * indicates otherwise.
+ */
+ if (ata_id_major_version(id) >= 7
+ && (((id[ATA_ID_CFSSE] & 0xC000) == 0x4000
+ && id[ATA_ID_CFSSE] & (1 << 13))
+ || ((id[ATA_ID_CSF_DEFAULT] & 0xC000) == 0x4000
+ && (id[ATA_ID_CSF_DEFAULT] & (1 << 13)))))
+ return 1;
+ return 0;
+}
+
static inline int ata_id_current_chs_valid(const u16 *id)
{
/* For ATA-1 devices, if the INITIALIZE DEVICE PARAMETERS command
--
To unsubscribe from this list: send the line "unsubscribe linux-ide" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
