Commit 9f8a2c23 authored by Tejun Heo's avatar Tejun Heo Committed by Jens Axboe
Browse files

scsi: replace sr_test_unit_ready() with scsi_test_unit_ready() 



The usage of TUR has been confusing involving several different
commits updating different parts over time.  Currently, the only
differences between scsi_test_unit_ready() and sr_test_unit_ready()
are,

* scsi_test_unit_ready() also sets sdev->changed on NOT_READY.

* scsi_test_unit_ready() returns 0 if TUR ended with UNIT_ATTENTION or
  NOT_READY.

Due to the above two differences, sr is using its own
sr_test_unit_ready(), but sd - the sole user of the above extra
handling - doesn't even need them.

Where scsi_test_unit_ready() is used in sd_media_changed(), the code
is looking for device ready w/ media present state which is true iff
TUR succeeds w/o sense data or UA, and when the device is not ready
for whatever reason sd_media_changed() explicitly marks media as
missing so there's no reason to set sdev->changed automatically from
scsi_test_unit_ready() on NOT_READY.

Drop both special handlings from scsi_test_unit_ready(), which makes
it equivalant to sr_test_unit_ready(), and replace
sr_test_unit_ready() with scsi_test_unit_ready().  Also, drop the
unnecessary explicit NOT_READY check from sd_media_changed().
Checking return value is enough for testing device readiness.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarJens Axboe <jaxboe@fusionio.com>
parent 638428ec

drivers/scsi/scsi_lib.c

+1 −12
Original line number Diff line number Diff line
@@ -1984,8 +1984,7 @@ EXPORT_SYMBOL(scsi_mode_sense); 
 *		in.

 *

 *	Returns zero if unsuccessful or an error if TUR failed.  For

 *	removable media, a return of NOT_READY or UNIT_ATTENTION is

 *	translated to success, with the ->changed flag updated.

 *	removable media, UNIT_ATTENTION sets ->changed flag.

 **/

int

scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries,
@@ -2012,16 +2011,6 @@ scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries, 
	} while (scsi_sense_valid(sshdr) &&

		 sshdr->sense_key == UNIT_ATTENTION && --retries);



	if (!sshdr)

		/* could not allocate sense buffer, so can't process it */

		return result;



	if (sdev->removable && scsi_sense_valid(sshdr) &&

	    (sshdr->sense_key == UNIT_ATTENTION ||

	     sshdr->sense_key == NOT_READY)) {

		sdev->changed = 1;

		result = 0;

	}

	if (!sshdr_external)

		kfree(sshdr);

	return result;

drivers/scsi/sd.c

+1 −9
Original line number Diff line number Diff line
@@ -1045,15 +1045,7 @@ static int sd_media_changed(struct gendisk *disk) 
					      sshdr);

	}



	/*

	 * Unable to test, unit probably not ready.   This usually

	 * means there is no disc in the drive.  Mark as changed,

	 * and we will figure it out later once the drive is

	 * available again.

	 */

	if (retval || (scsi_sense_valid(sshdr) &&

		       /* 0x3a is medium not present */

		       sshdr->asc == 0x3a)) {

	if (retval) {

		set_media_not_present(sdkp);

		retval = 1;

		goto out;

drivers/scsi/sr.c

+3 −28
Original line number Diff line number Diff line
@@ -165,32 +165,6 @@ static void scsi_cd_put(struct scsi_cd *cd) 
	mutex_unlock(&sr_ref_mutex);

}



/* identical to scsi_test_unit_ready except that it doesn't

 * eat the NOT_READY returns for removable media */

int sr_test_unit_ready(struct scsi_device *sdev, struct scsi_sense_hdr *sshdr)

{

	int retries = MAX_RETRIES;

	int the_result;

	u8 cmd[] = {TEST_UNIT_READY, 0, 0, 0, 0, 0 };



	/* issue TEST_UNIT_READY until the initial startup UNIT_ATTENTION

	 * conditions are gone, or a timeout happens

	 */

	do {

		the_result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL,

					      0, sshdr, SR_TIMEOUT,

					      retries--, NULL);

		if (scsi_sense_valid(sshdr) &&

		    sshdr->sense_key == UNIT_ATTENTION)

			sdev->changed = 1;



	} while (retries > 0 &&

		 (!scsi_status_is_good(the_result) ||

		  (scsi_sense_valid(sshdr) &&

		   sshdr->sense_key == UNIT_ATTENTION)));

	return the_result;

}



/*

 * This function checks to see if the media has been changed in the

 * CDROM drive.  It is possible that we have already sensed a change,
@@ -213,7 +187,8 @@ static int sr_media_change(struct cdrom_device_info *cdi, int slot) 
	}



	sshdr =  kzalloc(sizeof(*sshdr), GFP_KERNEL);

	retval = sr_test_unit_ready(cd->device, sshdr);

	retval = scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES,

				      sshdr);

	/*

	 * Media is considered to be present if TUR succeeds or fails with

	 * sense data indicating something other than media-not-present
@@ -784,7 +759,7 @@ static void get_capabilities(struct scsi_cd *cd) 
	}



	/* eat unit attentions */

	sr_test_unit_ready(cd->device, &sshdr);

	scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr);



	/* ask for mode page 0x2a */

	rc = scsi_mode_sense(cd->device, 0, 0x2a, buffer, 128,

drivers/scsi/sr.h

+0 −1
Original line number Diff line number Diff line
@@ -61,7 +61,6 @@ int sr_select_speed(struct cdrom_device_info *cdi, int speed); 
int sr_audio_ioctl(struct cdrom_device_info *, unsigned int, void *);



int sr_is_xa(Scsi_CD *);

int sr_test_unit_ready(struct scsi_device *sdev, struct scsi_sense_hdr *sshdr);



/* sr_vendor.c */

void sr_vendor_init(Scsi_CD *);

drivers/scsi/sr_ioctl.c

+1 −1
Original line number Diff line number Diff line
@@ -307,7 +307,7 @@ int sr_drive_status(struct cdrom_device_info *cdi, int slot) 
		/* we have no changer support */

		return -EINVAL;

	}

	if (0 == sr_test_unit_ready(cd->device, &sshdr))

	if (!scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr))

		return CDS_DISC_OK;



	/* SK/ASC/ASCQ of 2/4/1 means "unit is becoming ready" */

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