diff mbox series

[v4,10/10] scsi: mpt3sas: Introduce sas_ncq_prio_supported sysfs sttribute

Message ID 20210807041859.579409-11-damien.lemoal@wdc.com
State New
Headers show
Series libata cleanups and improvements | expand

Commit Message

Damien Le Moal Aug. 7, 2021, 4:18 a.m. UTC 
Similarly to AHCI, introduce the device sysfs attribute
sas_ncq_prio_supported to advertize if a SATA device supports the NCQ
priority feature. Without this new attribute, the user can only
discover if a SATA device supports NCQ priority by trying to enable
the feature use with the sas_ncq_prio_enable sysfs device attribute,
which fails when the device does not support high priroity commands.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
---
 drivers/scsi/mpt3sas/mpt3sas_ctl.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

Comments

Martin K. Petersen Aug. 10, 2021, 3:12 a.m. UTC | #1 
Damien,

> Similarly to AHCI, introduce the device sysfs attribute

> sas_ncq_prio_supported to advertize if a SATA device supports the NCQ

> priority feature. Without this new attribute, the user can only

> discover if a SATA device supports NCQ priority by trying to enable

> the feature use with the sas_ncq_prio_enable sysfs device attribute,

> which fails when the device does not support high priroity commands.


Applied patch #10 to 5.15/scsi-staging, thanks!

-- 
Martin K. Petersen	Oracle Linux Engineering
diff mbox series

Patch

diff --git a/drivers/scsi/mpt3sas/mpt3sas_ctl.c b/drivers/scsi/mpt3sas/mpt3sas_ctl.c
index b66140e4c370..f83d4d32d459 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_ctl.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_ctl.c
@@ -3918,6 +3918,24 @@  sas_device_handle_show(struct device *dev, struct device_attribute *attr,
 }
 static DEVICE_ATTR_RO(sas_device_handle);
 
+/**
+ * sas_ncq_prio_supported_show - Indicate if device supports NCQ priority
+ * @dev: pointer to embedded device
+ * @attr: sas_ncq_prio_supported attribute descriptor
+ * @buf: the buffer returned
+ *
+ * A sysfs 'read-only' sdev attribute, only works with SATA
+ */
+static ssize_t
+sas_ncq_prio_supported_show(struct device *dev,
+			    struct device_attribute *attr, char *buf)
+{
+	struct scsi_device *sdev = to_scsi_device(dev);
+
+	return sysfs_emit(buf, "%d\n", scsih_ncq_prio_supp(sdev));
+}
+static DEVICE_ATTR_RO(sas_ncq_prio_supported);
+
 /**
  * sas_ncq_prio_enable_show - send prioritized io commands to device
  * @dev: pointer to embedded device
@@ -3960,6 +3978,7 @@  static DEVICE_ATTR_RW(sas_ncq_prio_enable);
 struct device_attribute *mpt3sas_dev_attrs[] = {
 	&dev_attr_sas_address,
 	&dev_attr_sas_device_handle,
+	&dev_attr_sas_ncq_prio_supported,
 	&dev_attr_sas_ncq_prio_enable,
 	NULL,
 };