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.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (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 9089FC76196 for ; Fri, 31 Mar 2023 10:54:57 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4Pnxy76GNvz3f99 for ; Fri, 31 Mar 2023 21:54:55 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=ellerman.id.au header.i=@ellerman.id.au header.a=rsa-sha256 header.s=201909 header.b=AbBH1oq3; dkim-atps=neutral Received: from gandalf.ozlabs.org (mail.ozlabs.org [IPv6:2404:9400:2221:ea00::3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4Pnxx82PYBz3cJF for ; Fri, 31 Mar 2023 21:54:04 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=ellerman.id.au header.i=@ellerman.id.au header.a=rsa-sha256 header.s=201909 header.b=AbBH1oq3; dkim-atps=neutral Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 4Pnxx241sXz4x4r; Fri, 31 Mar 2023 21:53:58 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ellerman.id.au; s=201909; t=1680260040; bh=8QUsIUkBAgfdYfmbh//kvQTjF8lIKNNdvGDKhDBFuWg=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=AbBH1oq3KYd9qxnIlJOo0+7fIFnlw+pTGY+aW7PSFh5mdL880GrQYw72MEllwI+Fu Sn/TjtOyvGg7OR3BUbipFCYwSA5Yf2nP4FH3IDESzrgs1WW3lIHW1brLI1C+T0vdqO w7h94bj6QCeXfEHnv+HrsqMLGutoz7KwFzBsHbEUdhElNbDkqKiA30SW8SSCFAuM6A kCRKf/NqhSAmytND1L897CKg7WHSw2yq8uKMNZCp3nCncYacK6GlmMPLeKXd+O77Od hcyThV0TzQe1Jkalx5JTBxzOOc3L9GJwA/dRzLUW+2txepCtH9t9nPyoIkvQ9bZXyL kgIrl6k5DV6HA== From: Michael Ellerman To: Daniel Kolesa , linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH] drm/amdgpu: drop the long-double-128 powerpc check/hack In-Reply-To: References: Date: Fri, 31 Mar 2023 21:53:57 +1100 Message-ID: <87o7o9b396.fsf@mpe.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: dan@danny.cz, alexdeucher@gmail.com, tpearson@raptorengineering.com, amd-gfx@lists.freedesktop.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" "Daniel Kolesa" writes: > Commit c653c591789b ("drm/amdgpu: Re-enable DCN for 64-bit powerpc") > introduced this check as a workaround for the driver not building > with toolchains that default to 64-bit long double. ... > In mainline, this work is now fully done, so this check is fully > redundant and does not do anything except preventing AMDGPU DC > from being built on systems such as those using musl libc. The > last piece of work to enable this was commit c92b7fe0d92a > ("drm/amd/display: move remaining FPU code to dml folder") > and this has since been backported to 6.1 stable (in 6.1.7). > > Relevant issue: https://gitlab.freedesktop.org/drm/amd/-/issues/2288 I looked to pick this up for 6.3 but was still seeing build errors with some compilers. I assumed that was due to some fixes coming in linux-next that I didn't have. But applying the patch on v6.3-rc4 I still see build errors. This is building allyesconfig with the kernel.org GCC 12.2.0 / binutils 2.39 toolchain: powerpc64le-linux-gnu-ld: drivers/gpu/drm/amd/display/dc/dml/display_mode_lib.o uses hard float, arch/powerpc/lib/test_emulate_step.o uses soft float powerpc64le-linux-gnu-ld: failed to merge target specific data of file drivers/gpu/drm/amd/display/dc/dml/display_mode_lib.o etc. All the conflicts are between test_emulate_step.o and some file in drivers/gpu/drm/amd/display/dc/dml. So even with all the hard-float code isolated in the dml folder, we still hit build errors, because allyesconfig wants to link those hard-float using objects with soft-float objects from elsewhere in the kernel. It seems like the only workable fix is to force the kernel build to use 128-bit long double. I'll send a patch doing that. cheers