Re: [PATCH v6 3/3] ata: ATA Command Priority Disabled By Default

[Adam Manzanares <adam.manzanares@wdc.com>]

The 10/19/2016 14:38, Tejun Heo wrote:
> Hello,
> 
> Removed ata_ncq_prio_on() and renamed _on to _enable.  If I messed up
> anything, please let me know.
> 

Works as expected. Thanks for cleaning this up.

> Also, can you please send a follow-up patch to make the store function
> reject prio enabling if the device doesn't support it?
> 

I'll send something out shortly.

Take care,
Adam

> Thanks.
> 
> ------ 8< ------
> From 84f95243b5439a20c33837075b88926bfa00c4ec Mon Sep 17 00:00:00 2001
> From: Adam Manzanares <adam.manzanares@hgst.com>
> Date: Mon, 17 Oct 2016 11:27:30 -0700
> Subject: [PATCH 2/2] ata: ATA Command Priority Disabled By Default
> 
> Add a sysfs entry to turn on priority information being passed
> to a ATA device. By default this feature is turned off.
> 
> This patch depends on ata: Enabling ATA Command Priorities
> 
> tj: Renamed ncq_prio_on to ncq_prio_enable and removed trivial
>     ata_ncq_prio_on() and open-coded the test.
> 
> Signed-off-by: Adam Manzanares <adam.manzanares@hgst.com>
> Signed-off-by: Tejun Heo <tj@kernel.org>
> ---
>  drivers/ata/libahci.c     |  1 +
>  drivers/ata/libata-core.c |  3 ++-
>  drivers/ata/libata-scsi.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++
>  include/linux/libata.h    |  2 ++
>  4 files changed, 73 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
> index 0d028ea..ee7db31 100644
> --- a/drivers/ata/libahci.c
> +++ b/drivers/ata/libahci.c
> @@ -140,6 +140,7 @@ EXPORT_SYMBOL_GPL(ahci_shost_attrs);
>  struct device_attribute *ahci_sdev_attrs[] = {
>  	&dev_attr_sw_activity,
>  	&dev_attr_unload_heads,
> +	&dev_attr_ncq_prio_enable,
>  	NULL
>  };
>  EXPORT_SYMBOL_GPL(ahci_sdev_attrs);
> diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
> index 8346faf..b294339 100644
> --- a/drivers/ata/libata-core.c
> +++ b/drivers/ata/libata-core.c
> @@ -787,7 +787,8 @@ 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 ((dev->flags & ATA_DFLAG_NCQ_PRIO) &&
> +		    (dev->flags & ATA_DFLAG_NCQ_PRIO_ENABLE)) {
>  			if (class == IOPRIO_CLASS_RT)
>  				tf->hob_nsect |= ATA_PRIO_HIGH <<
>  						 ATA_SHIFT_PRIO;
> diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
> index 2bccc3c..87597a3 100644
> --- a/drivers/ata/libata-scsi.c
> +++ b/drivers/ata/libata-scsi.c
> @@ -271,6 +271,73 @@ DEVICE_ATTR(unload_heads, S_IRUGO | S_IWUSR,
>  	    ata_scsi_park_show, ata_scsi_park_store);
>  EXPORT_SYMBOL_GPL(dev_attr_unload_heads);
>  
> +static ssize_t ata_ncq_prio_enable_show(struct device *device,
> +					struct device_attribute *attr, char *buf)
> +{
> +	struct scsi_device *sdev = to_scsi_device(device);
> +	struct ata_port *ap;
> +	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) {
> +		rc = -ENODEV;
> +		goto unlock;
> +	}
> +
> +	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);
> +}
> +
> +static ssize_t ata_ncq_prio_enable_store(struct device *device,
> +					 struct device_attribute *attr,
> +					 const char *buf, size_t len)
> +{
> +	struct scsi_device *sdev = to_scsi_device(device);
> +	struct ata_port *ap;
> +	struct ata_device *dev;
> +	long int input;
> +	unsigned long flags;
> +	int rc;
> +
> +	rc = kstrtol(buf, 10, &input);
> +	if (rc)
> +		return rc;
> +	if ((input < 0) || (input > 1))
> +		return -EINVAL;
> +
> +	ap = ata_shost_to_port(sdev->host);
> +
> +	spin_lock_irqsave(ap->lock, flags);
> +	dev = ata_scsi_find_dev(ap, sdev);
> +	if (unlikely(!dev)) {
> +		rc = -ENODEV;
> +		goto unlock;
> +	}
> +
> +	if (input)
> +		dev->flags |= ATA_DFLAG_NCQ_PRIO_ENABLE;
> +	else
> +		dev->flags &= ~ATA_DFLAG_NCQ_PRIO_ENABLE;
> +
> +unlock:
> +	spin_unlock_irqrestore(ap->lock, flags);
> +
> +	return rc ? rc : len;
> +}
> +
> +DEVICE_ATTR(ncq_prio_enable, S_IRUGO | S_IWUSR,
> +	    ata_ncq_prio_enable_show, ata_ncq_prio_enable_store);
> +EXPORT_SYMBOL_GPL(dev_attr_ncq_prio_enable);
> +
>  void ata_scsi_set_sense(struct ata_device *dev, struct scsi_cmnd *cmd,
>  			u8 sk, u8 asc, u8 ascq)
>  {
> @@ -402,6 +469,7 @@ EXPORT_SYMBOL_GPL(dev_attr_sw_activity);
>  
>  struct device_attribute *ata_common_sdev_attrs[] = {
>  	&dev_attr_unload_heads,
> +	&dev_attr_ncq_prio_enable,
>  	NULL
>  };
>  EXPORT_SYMBOL_GPL(ata_common_sdev_attrs);
> diff --git a/include/linux/libata.h b/include/linux/libata.h
> index 90b69a6..c170be5 100644
> --- a/include/linux/libata.h
> +++ b/include/linux/libata.h
> @@ -167,6 +167,7 @@ enum {
>  	ATA_DFLAG_UNLOCK_HPA	= (1 << 18), /* unlock HPA */
>  	ATA_DFLAG_NCQ_SEND_RECV = (1 << 19), /* device supports NCQ SEND and RECV */
>  	ATA_DFLAG_NCQ_PRIO	= (1 << 20), /* device supports NCQ priority */
> +	ATA_DFLAG_NCQ_PRIO_ENABLE = (1 << 21), /* Priority cmds sent to dev */
>  	ATA_DFLAG_INIT_MASK	= (1 << 24) - 1,
>  
>  	ATA_DFLAG_DETACH	= (1 << 24),
> @@ -545,6 +546,7 @@ typedef void (*ata_postreset_fn_t)(struct ata_link *link, unsigned int *classes)
>  
>  extern struct device_attribute dev_attr_link_power_management_policy;
>  extern struct device_attribute dev_attr_unload_heads;
> +extern struct device_attribute dev_attr_ncq_prio_enable;
>  extern struct device_attribute dev_attr_em_message_type;
>  extern struct device_attribute dev_attr_em_message;
>  extern struct device_attribute dev_attr_sw_activity;
> -- 
> 2.7.4
>