From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg KH Subject: Re: [PATCH/RFC 1/4]device core changes Date: Thu, 11 Nov 2004 16:30:50 -0800 Message-ID: <20041112003050.GC11595@kroah.com> References: <1099887071.1750.243.camel@sli10-desk.sh.intel.com> <20041108225810.GB16197@kroah.com> <1099961418.15294.11.camel@sli10-desk.sh.intel.com> <1099971341.15294.48.camel@sli10-desk.sh.intel.com> <20041109045843.GA4849@kroah.com> <1099990981.15294.57.camel@sli10-desk.sh.intel.com> <20041110012443.GA9496@kroah.com> <1100051137.7825.6.camel@sli10-desk.sh.intel.com> <20041110042822.A13318@flint.arm.linux.org.uk> <1100156613.8769.26.camel@sli10-desk.sh.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1100156613.8769.26.camel-U5EdaLXB8smDugQYiPIPGdh3ngVCH38I@public.gmane.org> Sender: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: Li Shaohua Cc: Russell King , ACPI-DEV , lkml , Len Brown , Patrick Mochel List-Id: linux-acpi@vger.kernel.org On Thu, Nov 11, 2004 at 03:03:33PM +0800, Li Shaohua wrote: > On Wed, 2004-11-10 at 12:28, Russell King wrote: > > On Wed, Nov 10, 2004 at 09:45:37AM +0800, Li Shaohua wrote: > > > On Wed, 2004-11-10 at 09:24, Greg KH wrote: > > > > Maybe your other patches weren't so bad... If we implement them, can we > > > > drop the platform notify stuff? > > > Currently only ARM use 'platform_notify', and we can easily convert it > > > to use per-bus 'platform_bind'. One concern of per-bus 'platform_bind' > > > is we will have many '#ifdef ..' if many platforms implement their > > > per-bus 'platform_bind'. > > > > Except none of the merged ARM platforms use platform_notify, and I haven't > > seen any suggestion in the ARM world of why it would be needed. > Ok, let me summarize it. we now have two options: > 1. using 'platform_notify' > platform_notify only has one parameter 'struct device', we must know the > exact bus type of a device. We can identify the bus type from its name > (such as 'pci', 'ide'), but it's quite some ugly. Or we can add a 'type' > flag in the 'struct bus_type' to indicate the exact bus type which Greg > doesn't like it. One shortcoming is the method hasn't good flexibility, > we must add a new type whenever a new bus type is added. > 2. using per-bus type 'platform_bind' > Every bus type defines a 'platform_bind', so we know the exact bus type > naturally in platform_bind. The method can't handle special devices, > such as PCI root bridge, which hasn't a bus type, so no 'platform_bind' > is invoked for them. we must use some tricky methods to work around. > Another concern is the chaos if many platforms define 'platform_bind' > for a bus type, which isn't a big problem currently. > Greg, it seems you tend to option 2, isn't it? I don't tend toward option 2, I just don't see much of any workable option right now :( thanks, greg k-h ------------------------------------------------------- This SF.Net email is sponsored by: Sybase ASE Linux Express Edition - download now for FREE LinuxWorld Reader's Choice Award Winner for best database on Linux. http://ads.osdn.com/?ad_id=5588&alloc_id=12065&op=click