From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752726AbaFPXy2 (ORCPT ); Mon, 16 Jun 2014 19:54:28 -0400 Received: from gate.crashing.org ([63.228.1.57]:54064 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751337AbaFPXy0 (ORCPT ); Mon, 16 Jun 2014 19:54:26 -0400 Message-ID: <1402962847.7661.82.camel@pasglop> Subject: Re: [PATCH] offb: Fix little-endian support From: Benjamin Herrenschmidt To: Takashi Iwai Cc: Tomi Valkeinen , Jean-Christophe Plagniol-Villard , Cedric Le Goater , linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org Date: Tue, 17 Jun 2014 09:54:07 +1000 In-Reply-To: <1402904135.7661.34.camel@pasglop> References: <1400073709-15012-1-git-send-email-tiwai@suse.de> <1402904135.7661.34.camel@pasglop> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.12.2 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2014-06-16 at 17:35 +1000, Benjamin Herrenschmidt wrote: > I somewhat doubt that this (and 5:5:5) actually work, do they ? the > green gets split into two separate fields, which we can't express > properly here... So the conclusion of further investigation is: - The right fix is to fix qemu to flip endian - There's an open discussion as to whether qemu could do it automatically when the guest endian changes on powerpc as a quick fix, the long run approach is to have a register to control it, I'm working on it. offb can then "learn" to flick it like it does the palette hack today. - If we want to ever support foreign endian offb with X, we need to do things a bit differently based on the foreign endian bit that is already there. - We must revert the existing cmap swap patch from the kernel, it's broken and will break things when we fix qemu (and breaks with real HW in LE mode). I've sent a revert request to Linus and CC'ed stable. Cheers, Ben.