From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergei Shtylyov Subject: Re: [PATCH 1/2] [IDE] Platform IDE driver Date: Wed, 01 Aug 2007 16:39:32 +0400 Message-ID: <46B07F04.8040806@ru.mvista.com> References: <20070725165318.5331.23795.stgit@localhost.localdomain> <46A79DE0.8060405@ru.mvista.com> <46A79F14.9040409@freescale.com> <46A7A17C.8090505@ru.mvista.com> <46A7A1D5.7020003@freescale.com> <46A7A5E4.4090105@ru.mvista.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from gateway-1237.mvista.com ([63.81.120.155]:23466 "EHLO imap.sh.mvista.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751222AbXHAMhe (ORCPT ); Wed, 1 Aug 2007 08:37:34 -0400 In-Reply-To: Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Segher Boessenkool Cc: Scott Wood , linuxppc-dev@ozlabs.org, linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org Hello. Segher Boessenkool wrote: >> This doesn't mean that shift is better anyway. If everyone >> considers it >> better, I give up. But be warned that shift (stride) is not the only >> property >> characterizing register accesses -- the regs might be only accessible as >> 16/32-bit quantities, for example (16-bit is a real world example -- from >> Amiga or smth of that sort, IIRC). > More importantly, "reg-shift" doesn't say what part of > the bigger words to access. A common example is byte-wide > registers on a 32-bit-only bus; it's about 50%-50% between > connecting the registers to the low byte vs. connecting it > to the byte with the lowest address. We already have "big-endian" prop used in MPIC nodes, IIRC. Could try to "reuse" it here as well... > The only realistic way to handle all this is to put some > knowledge into the device driver. This does of course > also mean that no "reg-shift" property is needed; the > device driver can look at your "compatible" property, > instead. >>>> Why the heck should we care about the UART code taling about IDE?! >>> Consistency? >> We're not obliged to be consistent with every piece of the kernel >> code. > It would be nice to not name similar properties in the > device tree dissimilarly. Kernel code doesn't come into > the picture here. The "reg-shift" prop is yet unaccepted ad-hockery at this point. ;-) So, I don't see why we have to be consistent with it. > Segher WBR, Sergei