[PATCH] libata: return sense data in HDIO_DRIVE_CMD ioctl
Make the HDIO_DRIVE_CMD ioctl in libata (ATA command pass through) return a
few ATA registers to userspace, following the same convention as the
drivers/ide implementation of the same ioctl. This is needed to support ATA
commands like CHECK POWER MODE, which return information in nsectors.
This fixes "hdparm -C" on SATA drives.
Forcing the sense data read via the cc flag causes spurious check conditions,
so we filter these out (following the ATA command pass-through specification
T10/04-262r7).
Signed-off-by: Eran Tromer <eran@tromer.org>
Acked-by: Tejun Heo <htejun@gmail.com>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index b0d0cc4..7af2a4ba 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -164,10 +164,10 @@
{
int rc = 0;
u8 scsi_cmd[MAX_COMMAND_SIZE];
- u8 args[4], *argbuf = NULL;
+ u8 args[4], *argbuf = NULL, *sensebuf = NULL;
int argsize = 0;
- struct scsi_sense_hdr sshdr;
enum dma_data_direction data_dir;
+ int cmd_result;
if (arg == NULL)
return -EINVAL;
@@ -175,6 +175,10 @@
if (copy_from_user(args, arg, sizeof(args)))
return -EFAULT;
+ sensebuf = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_NOIO);
+ if (!sensebuf)
+ return -ENOMEM;
+
memset(scsi_cmd, 0, sizeof(scsi_cmd));
if (args[3]) {
@@ -191,7 +195,7 @@
data_dir = DMA_FROM_DEVICE;
} else {
scsi_cmd[1] = (3 << 1); /* Non-data */
- /* scsi_cmd[2] is already 0 -- no off.line, cc, or data xfer */
+ scsi_cmd[2] = 0x20; /* cc but no off.line or data xfer */
data_dir = DMA_NONE;
}
@@ -210,18 +214,46 @@
/* Good values for timeout and retries? Values below
from scsi_ioctl_send_command() for default case... */
- if (scsi_execute_req(scsidev, scsi_cmd, data_dir, argbuf, argsize,
- &sshdr, (10*HZ), 5)) {
+ cmd_result = scsi_execute(scsidev, scsi_cmd, data_dir, argbuf, argsize,
+ sensebuf, (10*HZ), 5, 0);
+
+ if (driver_byte(cmd_result) == DRIVER_SENSE) {/* sense data available */
+ u8 *desc = sensebuf + 8;
+ cmd_result &= ~(0xFF<<24); /* DRIVER_SENSE is not an error */
+
+ /* If we set cc then ATA pass-through will cause a
+ * check condition even if no error. Filter that. */
+ if (cmd_result & SAM_STAT_CHECK_CONDITION) {
+ struct scsi_sense_hdr sshdr;
+ scsi_normalize_sense(sensebuf, SCSI_SENSE_BUFFERSIZE,
+ &sshdr);
+ if (sshdr.sense_key==0 &&
+ sshdr.asc==0 && sshdr.ascq==0)
+ cmd_result &= ~SAM_STAT_CHECK_CONDITION;
+ }
+
+ /* Send userspace a few ATA registers (same as drivers/ide) */
+ if (sensebuf[0] == 0x72 && /* format is "descriptor" */
+ desc[0] == 0x09 ) { /* code is "ATA Descriptor" */
+ args[0] = desc[13]; /* status */
+ args[1] = desc[3]; /* error */
+ args[2] = desc[5]; /* sector count (0:7) */
+ if (copy_to_user(arg, args, sizeof(args)))
+ rc = -EFAULT;
+ }
+ }
+
+
+ if (cmd_result) {
rc = -EIO;
goto error;
}
- /* Need code to retrieve data from check condition? */
-
if ((argbuf)
&& copy_to_user(arg + sizeof(args), argbuf, argsize))
rc = -EFAULT;
error:
+ kfree(sensebuf);
kfree(argbuf);
return rc;
}
