From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTP id 9E7AADDE2A for ; Wed, 1 Aug 2007 08:31:15 +1000 (EST) In-Reply-To: <46A7A5E4.4090105@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 (Apple Message framework v623) Content-Type: text/plain; charset=US-ASCII; format=flowed Message-Id: From: Segher Boessenkool Subject: Re: [PATCH 1/2] [IDE] Platform IDE driver Date: Wed, 1 Aug 2007 00:31:04 +0200 To: Sergei Shtylyov Cc: linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , > 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. 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. Segher