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Commit bbe1fe7e authored by Eran Tromer's avatar Eran Tromer Committed by Jeff Garzik
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[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: default avatarEran Tromer <eran@tromer.org>
Acked-by: default avatarTejun Heo <htejun@gmail.com>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarJeff Garzik <jeff@garzik.org>
parent 4ad99f15

drivers/ata/libata-scsi.c

+39 −7
Original line number Diff line number Diff line
@@ -164,10 +164,10 @@ int ata_cmd_ioctl(struct scsi_device *scsidev, void __user *arg) 
{

	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 @@ int ata_cmd_ioctl(struct scsi_device *scsidev, void __user *arg) 
	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 @@ int ata_cmd_ioctl(struct scsi_device *scsidev, void __user *arg) 
		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 @@ int ata_cmd_ioctl(struct scsi_device *scsidev, void __user *arg) 


	/* 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;

}