From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 130A2E7716E for ; Thu, 5 Dec 2024 23:03:48 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tJKs6-0002Cs-Lh; Thu, 05 Dec 2024 18:02:59 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tJKry-0002Bd-QB for qemu-devel@nongnu.org; Thu, 05 Dec 2024 18:02:51 -0500 Received: from gate.crashing.org ([63.228.1.57]) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tJKrw-0004Pd-KW for qemu-devel@nongnu.org; Thu, 05 Dec 2024 18:02:50 -0500 Received: from [IPv6:::1] (localhost.localdomain [127.0.0.1]) by gate.crashing.org (8.14.1/8.14.1) with ESMTP id 4B5N0b5o001996; Thu, 5 Dec 2024 17:00:38 -0600 Message-ID: Subject: Re: [PATCH-for-9.2? v2 1/2] hw/display/vga: Do not reset 'big_endian_fb' in vga_common_reset() From: Benjamin Herrenschmidt To: Gerd Hoffmann Cc: Philippe =?ISO-8859-1?Q?Mathieu-Daud=E9?= , qemu-devel@nongnu.org, =?ISO-8859-1?Q?Marc-Andr=E9?= Lureau , "Michael S. Tsirkin" , Paolo Bonzini Date: Fri, 06 Dec 2024 10:00:37 +1100 In-Reply-To: References: <20241129101721.17836-1-philmd@linaro.org> <20241129101721.17836-2-philmd@linaro.org> <21c5e930-d7ee-4dd8-a238-862f4db87849@linaro.org> <2f6a993cd0e12c2bf903440f9f921d7af58bee36.camel@kernel.crashing.org> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.52.3-0ubuntu1 MIME-Version: 1.0 Received-SPF: pass client-ip=63.228.1.57; envelope-from=benh@kernel.crashing.org; helo=gate.crashing.org X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Tue, 2024-12-03 at 11:51 +0100, Gerd Hoffmann wrote: >=20 > The only case I'm aware of where the byte order is actually switched is > booting a ppc64le guest in a pseries machine, where the opal firmware > runs in bigendian mode and the linux kernel runs in little endian mode. >=20 > So here the changed reset behavior could actually make a difference, but > you will only notice if the opal firmware does *not* set the byte order > register. OPAL (well skiboot) doesn't display anything anyways (or at least it didn't when I wrote it :-). It just boots Linux as a bootloader. So as long as Linux itself sets the register it should be fine. Cheers, Ben.