Re: [RFC PATCH v3 7/9] ipu3-cio2: Check if pci_dev->dev's fwnode is a software_node in cio2_parse_firmware() and set FWNODE_GRAPH_DEVICE_DISABLED if so

From: Dan Scally
Date: Tue Oct 20 2020 - 15:56:13 EST


Hi Sakari

On 20/10/2020 13:06, Sakari Ailus wrote:
> Hi Andy,
>
> On Tue, Oct 20, 2020 at 12:19:58PM +0300, Andy Shevchenko wrote:
>> On Mon, Oct 19, 2020 at 11:59:01PM +0100, Daniel Scally wrote:
>>> fwnode_graph_get_endpoint_by_id() will optionally parse enabled devices
>>> only; that status being determined through the .device_is_available() op
>>> of the device's fwnode. As software_nodes don't have that operation and
>>> adding it is meaningless, we instead need to check if the device's fwnode
>>> is a software_node and if so pass the appropriate flag to disable that
>>> check
>> Period.
>>
>> I'm wondering if actually this can be hidden in fwnode_graph_get_endpoint_by_id().
> The device availability test is actually there for a reason. Some firmware
> implementations put all the potential devices in the tables and only one
> (of some) of them are available.
>
> Could this be implemented so that if the node is a software node, then get
> its parent and then see if that is available?
>
> I guess that could be implemented in software node ops. Any opinions?
Actually when considering the cio2 device, it seems that
set_secondary_fwnode() actually overwrites the _primary_, given
fwnode_is_primary(dev->fwnode) returns false. So in at least some cases,
this wouldn't work.