From mboxrd@z Thu Jan 1 00:00:00 1970 From: Albert ARIBAUD Date: Mon, 10 Feb 2014 17:12:24 +0100 Subject: [U-Boot] [PATCH v2] arm: Switch to -mno-unaligned-access when supported by the compiler In-Reply-To: References: <1391533533-21664-1-git-send-email-trini@ti.com> <20140210102447.03a4007f@lilith> <20140210132139.GT7049@bill-the-cat> <20140210155751.23849fcb@lilith> Message-ID: <20140210171224.477e2906@lilith> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Hi M?ns, On Mon, 10 Feb 2014 15:14:49 +0000, M?ns Rullg?rd wrote: > Albert ARIBAUD writes: > > > Hi Tom, > > > > On Mon, 10 Feb 2014 08:21:39 -0500, Tom Rini wrote: > > > >> On Mon, Feb 10, 2014 at 10:24:47AM +0100, Albert ARIBAUD wrote: > >> > Hi Tom, > >> > > >> > On Tue, 4 Feb 2014 12:05:33 -0500, Tom Rini wrote: > >> > > >> > > When we tell the compiler to optimize for ARMv7 it assumes a default of > >> > > unaligned accesses being supported at the hardware level and can make > >> > > use of this to perform what it deems as an optimization in any case, > >> > > including allowing for data to become unaligned. We explicitly disallow > >> > > this hardware feature so we must tell the compiler. > >> > > > >> > > Cc: Albert ARIBAUD > >> > > Cc: Mans Rullgard > >> > > Signed-off-by: Tom Rini > >> > > >> > NAK -- the discrepancy between the compiler being told to allow native > >> > unaligned accesses while at the same time telling the hardware to trap > >> > them is conscious and voluntary. It was chosen to help detect unaligned > >> > accesses which are rarely necessary and can be explicitly performed by > >> > software on a case by case basis. > >> > > >> > If and when a specific file requires unaligned access which cannot be > >> > made by some other mean than enabling -mno-unaligned-access, then this > >> > file should have it added, not the whole of U-Boot. > >> > >> Right, I recall the discussion, and we chose wrong. > > > > I am quite prepared to discuss whether we chose wrong or right, and > > to change my mind when the conditions are right, but I'll need more than > > such a short and simple statement. :) > > I already gave you a detailed explanation some months ago. You refused > to read it. I can hardly have "refused to read" a message which I *answered*, laid out how I thought the issue should be solved... and got no answer after this. Now, are we going to discuss the technical issue or is this going to go debian-TC -- which I wouldn't see the point of. Amicalement, -- Albert.