Commit 2360fa18 authored by Damien Le Moal's avatar Damien Le Moal Committed by Jens Axboe
Browse files

libata: cleanup NCQ priority handling 



The ata device flag ATA_DFLAG_NCQ_PRIO indicates if a device supports
the NCQ Priority feature while the ATA_DFLAG_NCQ_PRIO_ENABLE device
flag indicates if the feature is enabled. Enabling NCQ priority use is
controlled by the user through the device sysfs attribute
ncq_prio_enable. As a result, the ATA_DFLAG_NCQ_PRIO flag should not be
cleared when ATA_DFLAG_NCQ_PRIO_ENABLE is not set as the device still
supports the feature even after the user disables it. This leads to the
following cleanups:
- In ata_build_rw_tf(), set a command high priority bit based on the
  ATA_DFLAG_NCQ_PRIO_ENABLE flag, not on the ATA_DFLAG_NCQ flag. That
  is, set a command high priority only if the user enabled NCQ priority
  use.
- In ata_dev_config_ncq_prio(), ATA_DFLAG_NCQ_PRIO should not be cleared
  if ATA_DFLAG_NCQ_PRIO_ENABLE is not set. If the device does not
  support NCQ priority, both ATA_DFLAG_NCQ_PRIO and
  ATA_DFLAG_NCQ_PRIO_ENABLE must be cleared.

With the above ata_dev_config_ncq_prio() change, ATA_DFLAG_NCQ_PRIO flag
is set on device scan and revalidation. There is no need to trigger a
device revalidation in ata_ncq_prio_enable_store() when the user enables
the use of NCQ priority. Remove the revalidation code from that funciton
to simplify it. Also change the return value from -EIO to -EINVAL when a
user tries to enable NCQ priority for a device that does not support
this feature.  While at it, also simplify ata_ncq_prio_enable_show().

Overall, there is no functional change introduced by this patch.

Signed-off-by: default avatarDamien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20210816014456.2191776-7-damien.lemoal@wdc.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 891fd7c6

drivers/ata/libata-core.c

+14 −18
Original line number Diff line number Diff line
@@ -712,11 +712,9 @@ int ata_build_rw_tf(struct ata_taskfile *tf, struct ata_device *dev, 
		if (tf->flags & ATA_TFLAG_FUA)

			tf->device |= 1 << 7;



		if (dev->flags & ATA_DFLAG_NCQ_PRIO) {

			if (class == IOPRIO_CLASS_RT)

				tf->hob_nsect |= ATA_PRIO_HIGH <<

						 ATA_SHIFT_PRIO;

		}

		if (dev->flags & ATA_DFLAG_NCQ_PRIO_ENABLE &&

		    class == IOPRIO_CLASS_RT)

			tf->hob_nsect |= ATA_PRIO_HIGH << ATA_SHIFT_PRIO;

	} else if (dev->flags & ATA_DFLAG_LBA) {

		tf->flags |= ATA_TFLAG_LBA;
@@ -2178,11 +2176,6 @@ static void ata_dev_config_ncq_prio(struct ata_device *dev) 
	struct ata_port *ap = dev->link->ap;

	unsigned int err_mask;



	if (!(dev->flags & ATA_DFLAG_NCQ_PRIO_ENABLE)) {

		dev->flags &= ~ATA_DFLAG_NCQ_PRIO;

		return;

	}



	err_mask = ata_read_log_page(dev,

				     ATA_LOG_IDENTIFY_DEVICE,

				     ATA_LOG_SATA_SETTINGS,
@@ -2190,18 +2183,21 @@ static void ata_dev_config_ncq_prio(struct ata_device *dev) 
				     1);

	if (err_mask) {

		ata_dev_dbg(dev,

			    "failed to get Identify Device data, Emask 0x%x\n",

			    "failed to get SATA settings log, Emask 0x%x\n",

			    err_mask);

		return;

		goto not_supported;

	}



	if (ap->sector_buf[ATA_LOG_NCQ_PRIO_OFFSET] & BIT(3)) {

	if (!(ap->sector_buf[ATA_LOG_NCQ_PRIO_OFFSET] & BIT(3)))

		goto not_supported;



	dev->flags |= ATA_DFLAG_NCQ_PRIO;

	} else {

		dev->flags &= ~ATA_DFLAG_NCQ_PRIO;

		ata_dev_dbg(dev, "SATA page does not support priority\n");

	}



	return;



not_supported:

	dev->flags &= ~ATA_DFLAG_NCQ_PRIO_ENABLE;

	dev->flags &= ~ATA_DFLAG_NCQ_PRIO;

}



static int ata_dev_config_ncq(struct ata_device *dev,

drivers/ata/libata-sata.c

+12 −25
Original line number Diff line number Diff line
@@ -839,23 +839,17 @@ static ssize_t ata_ncq_prio_enable_show(struct device *device, 
					char *buf)

{

	struct scsi_device *sdev = to_scsi_device(device);

	struct ata_port *ap;

	struct ata_port *ap = ata_shost_to_port(sdev->host);

	struct ata_device *dev;

	bool ncq_prio_enable;

	int rc = 0;



	ap = ata_shost_to_port(sdev->host);



	spin_lock_irq(ap->lock);

	dev = ata_scsi_find_dev(ap, sdev);

	if (!dev) {

	if (!dev)

		rc = -ENODEV;

		goto unlock;

	}



	else

		ncq_prio_enable = dev->flags & ATA_DFLAG_NCQ_PRIO_ENABLE;



unlock:

	spin_unlock_irq(ap->lock);



	return rc ? rc : snprintf(buf, 20, "%u\n", ncq_prio_enable);
@@ -869,7 +863,7 @@ static ssize_t ata_ncq_prio_enable_store(struct device *device, 
	struct ata_port *ap;

	struct ata_device *dev;

	long int input;

	int rc;

	int rc = 0;



	rc = kstrtol(buf, 10, &input);

	if (rc)
@@ -883,26 +877,19 @@ static ssize_t ata_ncq_prio_enable_store(struct device *device, 
		return  -ENODEV;



	spin_lock_irq(ap->lock);



	if (!(dev->flags & ATA_DFLAG_NCQ_PRIO)) {

		rc = -EINVAL;

		goto unlock;

	}



	if (input)

		dev->flags |= ATA_DFLAG_NCQ_PRIO_ENABLE;

	else

		dev->flags &= ~ATA_DFLAG_NCQ_PRIO_ENABLE;



	dev->link->eh_info.action |= ATA_EH_REVALIDATE;

	dev->link->eh_info.flags |= ATA_EHI_QUIET;

	ata_port_schedule_eh(ap);

	spin_unlock_irq(ap->lock);



	ata_port_wait_eh(ap);



	if (input) {

		spin_lock_irq(ap->lock);

		if (!(dev->flags & ATA_DFLAG_NCQ_PRIO)) {

			dev->flags &= ~ATA_DFLAG_NCQ_PRIO_ENABLE;

			rc = -EIO;

		}

unlock:

	spin_unlock_irq(ap->lock);

	}



	return rc ? rc : len;

}