From mboxrd@z Thu Jan  1 00:00:00 1970
From: Christoph Hellwig <hch@infradead.org>
Subject: Re: RFC: ACPI/scsi/libata integration and hotswap
Date: Fri, 9 Dec 2005 11:42:46 +0000
Message-ID: <20051209114246.GB16945@infradead.org>
References: <20051208030242.GA19923@srcf.ucam.org> <20051208091542.GA9538@infradead.org> <20051208132657.GA21529@srcf.ucam.org> <20051208133308.GA13267@infradead.org> <20051208133945.GA21633@srcf.ucam.org> <1134050498.17102.2.camel@localhost.localdomain> <20051208141811.GB21715@srcf.ucam.org> <1134052433.17102.17.camel@localhost.localdomain> <20051208145257.GB21946@srcf.ucam.org> <20051208171901.GA22451@srcf.ucam.org>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Return-path: <linux-scsi-owner@vger.kernel.org>
Content-Disposition: inline
In-Reply-To: <20051208171901.GA22451@srcf.ucam.org>
Sender: linux-scsi-owner@vger.kernel.org
To: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>, Christoph Hellwig <hch@infradead.org>, randy_d_dunlap@linux.intel.com, linux-ide@vger.kernel.org, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, acpi-devel@lists.sourceforge.net
List-Id: linux-ide@vger.kernel.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.