Re: RFC: ACPI/scsi/libata integration and hotswap

[Christoph Hellwig <hch@infradead.org>]

On Thu, Dec 08, 2005 at 05:19:01PM +0000, Matthew Garrett wrote:
> This turns out to be quite difficult, and I can't see a clean way of 
> doing it without touching scsi or rewriting chunks of the ACPI glue 
> code.
> 
> The basic flow of code required here is:
> 
> 1) scsi layer registers a new device
> 2) platform_notify is called, which is (in this case) 
> acpi_platform_notify
> 3) acpi_platform_notify checks whether it knows dev->bus. If so, it 
> calls appropriate callbacks.
> 
> Without touching scsi, there doesn't seem to be any way for (3) to work 
> if scsi is a module. Would a simple
> 
> #ifdef CONFIG_ACPI
> acpi_scsi_init(&scsi_bus_type)
> #endif
> 
> in the scsi code be acceptable? If not, then we have some difficulty. 
> The acpi glue code has to be statically linked in, so it can't rely on 
> anything that directly references the scsi code.

As a concept it's _much_ better.  Although it should be platform_scsi_init
and every architecture would provide an, in most cases noop, implementation.