Re: [PATCH V9 1/8] ACPI: I/O Remapping Table (IORT) initial support

From: Rafael J. Wysocki
Date: Tue Sep 06 2016 - 07:15:54 EST


On Tue, Sep 6, 2016 at 9:24 AM, Tomasz Nowicki <tn@xxxxxxxxxxxx> wrote:
> Hi Rafael,
>
>
> On 05.09.2016 22:29, Rafael J. Wysocki wrote:
>>
>> On Mon, Sep 5, 2016 at 10:05 PM, Tomasz Nowicki <tn@xxxxxxxxxxxx> wrote:
>>>

[cut]

> static acpi_status iort_match_node_callback(struct acpi_iort_node *node,
> void *context)
> {
> struct device *dev = context;
> acpi_status status = AE_NOT_FOUND;
>
> switch (node->type) {
> case ACPI_IORT_NODE_NAMED_COMPONENT: {
> struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL };
> struct acpi_device *adev = to_acpi_device_node(dev->fwnode);
> struct acpi_iort_named_component *ncomp;
>
> if (!adev)
> break;
>
> status = acpi_get_name(adev->handle, ACPI_FULL_PATHNAME,
> &buf);
> if (ACPI_FAILURE(status)) {
> dev_warn(dev, "Can't get device full path name\n");
> break;
> }
>
> ncomp = (struct acpi_iort_named_component *)node->node_data;
> if (!strcmp(ncomp->device_name, buf.pointer))
> status = AE_OK;
>
> acpi_os_free(buf.pointer);
> break;
> }
> case ACPI_IORT_NODE_PCI_ROOT_COMPLEX: {
> struct acpi_iort_root_complex *pci_rc;
> struct pci_bus *bus;
>
> bus = to_pci_bus(dev);
> pci_rc = (struct acpi_iort_root_complex *)node->node_data;
>
> /*
> * It is assumed that PCI segment numbers maps one-to-one
> * with root complexes. Each segment number can represent
> only
> * one root complex.
> */
> if (pci_rc->pci_segment_number == pci_domain_nr(bus))
> status = AE_OK;
>
> break;
> }
> }
>
> return status;
> }
>
>>
>>> + } else {
>>> + int match;
>>> +
>>> + match = !strcmp(ncomp->device_name,
>>> buffer.pointer);
>>> + acpi_os_free(buffer.pointer);
>>> +
>>> + if (match)
>>> + return AE_OK;
>>> + }
>>> +
>>> + break;
>>> + }
>>> + case ACPI_IORT_NODE_PCI_ROOT_COMPLEX: {
>>
>>
>> What is the brace for?
>
>
> To create namespace for below local variables. The same for
> ACPI_IORT_NODE_NAMED_COMPONENT case.

This looks weird, though. At least nest it in a usual way.

And what would be wrong with using if () {} else if () {} instead?

There are two cases only here anyway.

Thanks,
Rafael