From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ankita Garg Date: Mon, 30 May 2011 22:39:17 +0530 Subject: [U-Boot] Help with exporting memory power management info in u-boot In-Reply-To: <20110530110157.10FBC14EBCB@gemini.denx.de> References: <20110530063940.GB16331@in.ibm.com> <20110530094926.53801C586F9@gemini.denx.de> <20110530102030.GD18375@in.ibm.com> <20110530110157.10FBC14EBCB@gemini.denx.de> Message-ID: <20110530170917.GC23950@in.ibm.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Hi, On Mon, May 30, 2011 at 01:01:57PM +0200, Wolfgang Denk wrote: > Dear Ankita Garg, > > In message <20110530102030.GD18375@in.ibm.com> you wrote: > > > > I agree with the above. Its not the power consumed by u-boot that is of > > concern. We want u-boot support in exporting additional information to > > the kernel, regarding the memory hardware characteristics specific to > > power management. For instance, if u-boot could inform the kernel about > > the boundaries at which PASR is supported on the underlying platform, > > that information could then be used by the kernel to exploit this > > feature. Like, this information would be encapsulated in a device-tree > > node maybe ? > > I agree that is is a good idea to encode such information in the > device tree. U-Boot can also help to update memory related notes in > the device tree, for example by inserting their actual physical > addresses and sizes. > > The rest, including information about memory power management > properties of such nodes in the device tree, is of no concern to > U-Boot and should just be passed on unchanged. > > In my opinion it is therefore the responsibility of the creator of > the device tree to provide a proper description of the hardware, > including the memory power management information. > Ok, thats true. So I guess a better place would be the linux-arm-kernel list to discuss about potential device-tree interface design. Thanks Wolfgang ! -- Regards, Ankita Garg (ankita at in.ibm.com) Linux Technology Center IBM India Systems & Technology Labs, Bangalore, India