On Thursday 28 April 2016 17:34:10 Arnd Bergmann wrote:
On Thursday 28 April 2016 10:12:12 Bjorn Helgaas wrote:
Right, we don't have a good mechanism for passing more info into pci_create_root_bus(). Maybe the caller could fill in a struct so we have a chance to extend it without having to change all the existing callers.
I wonder if there's a design pattern we can copy, e.g., would something like the scsi_host_alloc(), scsi_add_host(), scsi_scan_host() model work here?
Yes, I think that is a good idea in general. Especially now that we have separate the ARM code from pci_common_init_dev and pci_sys_data, that can help with cleanups in the other drivers as well.
I see two common variations in other subsystems: some use a special alloc() function that you pass the size of the private data into, while others just expect you to embed a structure inside of the driver specific one allocate that separately to have the generic registration function fill out the common fields.
I have a slight preference for the second, but they are really the same thing basically.
I've tried this out now, and will follow up with a separate patch series. Overall, I think it works out well, though I haven't gotten to the point of actually saving code yet. I've converted two drivers for demonstration.
Arnd