Commit 6a8438de authored by Damien Le Moal's avatar Damien Le Moal
Browse files

ata: libata-scsi: Fix initialization of device queue depth 



For SATA devices supporting NCQ, drivers using libsas first initialize a
scsi device queue depth based on the controller and device capabilities,
leading to the scsi device queue_depth field being 32 (ATA maximum queue
depth) for most setup. However, if libata was loaded using the
force=[ID]]noncq argument, the default queue depth should be set to 1 to
reflect the fact that queuable commands will never be used. This is
consistent with manually setting a device queue depth to 1 through sysfs
as that disables NCQ use for the device.

Fix ata_scsi_dev_config() to honor the noncq parameter by sertting the
device queue depth to 1 for devices that do not have the ATA_DFLAG_NCQ
flag set.

Signed-off-by: default avatarDamien Le Moal <damien.lemoal@opensource.wdc.com>
Tested-by: default avatarJohn Garry <john.garry@huawei.com>
parent ea08aec7

drivers/ata/libata-scsi.c

+4 −6
Original line number Diff line number Diff line
@@ -1055,6 +1055,7 @@ EXPORT_SYMBOL_GPL(ata_scsi_dma_need_drain); 
int ata_scsi_dev_config(struct scsi_device *sdev, struct ata_device *dev)

{

	struct request_queue *q = sdev->request_queue;

	int depth = 1;



	if (!ata_id_has_unload(dev->id))

		dev->flags |= ATA_DFLAG_NO_UNLOAD;
@@ -1100,13 +1101,10 @@ int ata_scsi_dev_config(struct scsi_device *sdev, struct ata_device *dev) 
	if (dev->flags & ATA_DFLAG_AN)

		set_bit(SDEV_EVT_MEDIA_CHANGE, sdev->supported_events);



	if (dev->flags & ATA_DFLAG_NCQ) {

		int depth;



	if (dev->flags & ATA_DFLAG_NCQ)

		depth = min(sdev->host->can_queue, ata_id_queue_depth(dev->id));

	depth = min(ATA_MAX_QUEUE, depth);

	scsi_change_queue_depth(sdev, depth);

	}



	if (dev->flags & ATA_DFLAG_TRUSTED)

		sdev->security_supported = 1;