Re: [PATCH v7 04/13] slimbus: core: Add slim controllers support

[Srinivas Kandagatla]

thanks for the comments.


On 16/11/17 16:42, Vinod Koul wrote:
> On Wed, Nov 15, 2017 at 02:10:34PM +0000, srinivas.kandagatla@xxxxxxxxxx wrote:
>
> > +static void slim_dev_release(struct device *dev)
> > +{
> > +	struct slim_device *sbdev = to_slim_device(dev);
> > +
> > +	put_device(sbdev->ctrl->dev);
>
> which device would that be?
This is controller device

> > +static int slim_add_device(struct slim_controller *ctrl,
> > +			   struct slim_device *sbdev,
> > +			   struct device_node *node)
> > +{
> > +	sbdev->dev.bus = &slimbus_bus;
> > +	sbdev->dev.parent = ctrl->dev;
> > +	sbdev->dev.release = slim_dev_release;
> > +	sbdev->dev.driver = NULL;
> > +	sbdev->ctrl = ctrl;
> > +
> > +	dev_set_name(&sbdev->dev, "%x:%x:%x:%x",
> > +				  sbdev->e_addr.manf_id,
> > +				  sbdev->e_addr.prod_code,
> > +				  sbdev->e_addr.dev_index,
> > +				  sbdev->e_addr.instance);
> > +
> > +	get_device(ctrl->dev);
>
> is this controller device and you ensuring it doesnt go away while you have
> slaves on it?

Yes.

> > +static struct slim_device *slim_alloc_device(struct slim_controller *ctrl,
> > +					     struct slim_eaddr *eaddr,
> > +					     struct device_node *node)
> > +{
> > +	struct slim_device *sbdev;
> > +	int ret;
> > +
> > +	sbdev = kzalloc(sizeof(struct slim_device), GFP_KERNEL);
>
> Usual kernel way of doing is kzalloc(*sbdev)
I agree will fix it in next version.

> > +void slim_report_absent(struct slim_device *sbdev)
> > +{
> > +	struct slim_controller *ctrl = sbdev->ctrl;
> > +
> > +	if (!ctrl)
> > +		return;
> > +
> > +	/* invalidate logical addresses */
> > +	mutex_lock(&ctrl->lock);
> > +	sbdev->is_laddr_valid = false;
> > +	mutex_unlock(&ctrl->lock);
> > +
> > +	ida_simple_remove(&ctrl->laddr_ida, sbdev->laddr);
> > +	slim_device_update_status(sbdev, SLIM_DEVICE_STATUS_DOWN);
> > +}
> > +EXPORT_SYMBOL_GPL(slim_report_absent);
>
> Do you have APIs for report present too, if so why not add te status in
> argument as you may have common handling
Yes, We do  have api for reporting too, I will give it a try to combine 
both.

> > +static int slim_device_alloc_laddr(struct slim_device *sbdev,
> > +				   u8 *laddr, bool report_present)
> > +{
> > +	struct slim_controller *ctrl = sbdev->ctrl;
> > +	int ret;
> > +
> > +	mutex_lock(&ctrl->lock);
> > +	if (ctrl->get_laddr) {
> > +		ret = ctrl->get_laddr(ctrl, &sbdev->e_addr, laddr);
> > +		if (ret < 0)
> > +			goto err;
> > +	} else if (report_present) {
> > +		ret = ida_simple_get(&ctrl->laddr_ida,
> > +				     0, SLIM_LA_MANAGER - 1, GFP_KERNEL);
> > +		if (ret < 0)
> > +			goto err;
> > +
> > +		*laddr = ret;
> > +	} else {
> > +		ret = -EINVAL;
> > +		goto err;
> > +	}
> > +
> > +	if (ctrl->set_laddr) {
> > +		ret = ctrl->set_laddr(ctrl, &sbdev->e_addr, *laddr);
> > +		if (ret) {
> > +			ret = -EINVAL;
> > +			goto err;
> > +		}
> > +	}
> > +
> > +	sbdev->laddr = *laddr;
>
> if you have this in sbdev, then why have this as an arg also?
Yes makes sens, laddr argument in this function is redundant, it can be 
removed totally.
> > +	sbdev->is_laddr_valid = true;
>
> shouldn't non-zero value signify that?
0 is also a valid laddr.

>