On Mon, Jan 11, 2016 at 5:27 PM, Russell King - ARM Linux
[off-list ref] wrote:

On Mon, Jan 11, 2016 at 05:13:20PM +0200, Andy Shevchenko wrote:

quoted

On Mon, Jan 11, 2016 at 3:26 PM, Aleksey Makarov
[off-list ref] wrote:

quoted

From: Graeme Gregory <redacted>

quoted

quoted

+static int amba_handler_attach(struct acpi_device *adev,
+                               const struct acpi_device_id *id)
+{
+       struct amba_device *dev;
+       struct resource_entry *rentry;
+       struct list_head resource_list;
+       bool address_found = false;
+       int irq_no = 0;
+       int ret;
+
+       /* If the ACPI node already has a physical device attached, skip it. */
+       if (adev->physical_node_count)
+               return 0;
+
+       dev = amba_device_alloc(dev_name(&adev->dev), 0, 0);
+       if (!dev) {
+               dev_err(&adev->dev, "%s(): amba_device_alloc() failed\n",
+                       __func__);
+               return -ENOMEM;
+       }
+
+       INIT_LIST_HEAD(&resource_list);
+       ret = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
+       if (ret < 0)
+               goto err_free;
+
+       list_for_each_entry(rentry, &resource_list, node) {
+               switch (resource_type(rentry->res)) {
+               case IORESOURCE_MEM:
+                       if (!address_found) {
+                               dev->res = *rentry->res;

dev->res is 0 before this one, right? Could you use this fact instead
of address_found flag?

amba_device_alloc() zero-initialises everything.  However, dev->res is
a struct resource, and I'd prefer _this_ method that the OT is using
to testing some random part of struct resource.

So, you mean resource->start = 0 is not enough reliable?

quoted

quoted

+               default:
+                       dev_warn(&adev->dev, "Invalid resource\n");

Why? Isn't possible to have other resources for the devices?

AMBA primecell devices have one memory region, and a number of
interrupts.  Other resource types don't make sense.

But isn't warning on the other side too noisy?

quoted

quoted

+       ret = amba_device_add(dev, &iomem_resource);
+       if (ret) {

ret < 0?

What to do if ret > 0? It will be considered as not error. Please,
check what function returns and adjust this.

Non-zero is treated as an error by amba_device_add().

Doing otherwise
here puts it at odds to the outcome of that function.  This code is fine.

Yes, and in this case ret > 0 should be converted to an appropriate
error code, otherwise ACPI core will consider this as a normal
execution, right?

-- 
With Best Regards,
Andy Shevchenko