From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1249B1D86FF; Tue, 11 Nov 2025 01:32:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762824731; cv=none; b=rT+jqBfvkdsd7dU9HOY40lGXePmWjg6AEFD7SLR6/8XXLtl8/nVula7jaCg7Q3tqYqRwfbl+Qs7hnl5WzXCwEumpoiskhvT/f2ooa6Iicexzfqzppi6uYtCCOHh+lPzZlSixF1nvf8XyenmiOcScjNBDl0mbdauzcOA3TE7gTNY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762824731; c=relaxed/simple; bh=NmOsgLiDgu8G5787qnntXzk+xC3ufACIxVlaHuPQm20=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ZXIzy9uNNDAbFHoTkrrS3OJohtEk1vB+vAN4EnfM9MfWjg18W2Xb5muLocqNBJ3OsL8TmOCMhLGrVHMkTmY2y33ER6dlTHPOn7Zj8bmGzXs1feqw4u9GhtON9IvGpKSvp/pOMSZgtAmVdjB7CynVzr33JctYxF/lTg3XHPvY/SI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=vnsn8130; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="vnsn8130" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8FCE4C4CEFB; Tue, 11 Nov 2025 01:32:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1762824730; bh=NmOsgLiDgu8G5787qnntXzk+xC3ufACIxVlaHuPQm20=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vnsn8130YDhuNhy9y9O/dLDuZ9O5lkCOsOCqQUQTnCoFF08Zbvg+Koh9zzoz0vAqZ vZBdxd0CmBrgEWXKxhXDbAYhKGikTdqL+sbLAt5+B9eNN/oqnVZbl/3croZRsdHHOB Y/8sw5GuEPk4mxqUDwg3AnCeWKnzXPDtC+tS7OHo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Asiacn <710187964@qq.com>, Xi Ruoyao , Huacai Chen , Alex Hung , Alex Deucher , Sasha Levin Subject: [PATCH 6.17 559/849] drm/amd/display/dml2: Guard dml21_map_dc_state_into_dml_display_cfg with DC_FP_START Date: Tue, 11 Nov 2025 09:42:09 +0900 Message-ID: <20251111004549.926540023@linuxfoundation.org> X-Mailer: git-send-email 2.51.2 In-Reply-To: <20251111004536.460310036@linuxfoundation.org> References: <20251111004536.460310036@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Xi Ruoyao [ Upstream commit c97a7dccb3ed680031011cfc1457506e6de49c9a ] dml21_map_dc_state_into_dml_display_cfg calls (the call is usually inlined by the compiler) populate_dml21_surface_config_from_plane_state and populate_dml21_plane_config_from_plane_state which may use FPU. In a x86-64 build: $ objdump --disassemble=dml21_map_dc_state_into_dml_display_cfg \ > drivers/gpu/drm/amd/display/dc/dml2/dml21/dml21_translation_helper.o | > grep %xmm -c 63 Thus it needs to be guarded with DC_FP_START. But we must note that the current code quality of the in-kernel FPU use in AMD dml2 is very much problematic: we are actually calling DC_FP_START in dml21_wrapper.c here, and this translation unit is built with CC_FLAGS_FPU. Strictly speaking this does not make any sense: with CC_FLAGS_FPU the compiler is allowed to generate FPU uses anywhere in the translated code, perhaps out of the DC_FP_START guard. This problematic pattern also occurs in at least dml2_wrapper.c, dcn35_fpu.c, and dcn351_fpu.c. Thus we really need a careful audit and refactor for the in-kernel FPU uses, and this patch is simply whacking a mole. However per the reporter, whacking this mole is enough to make a 9060XT "just work." Reported-by: Asiacn <710187964@qq.com> Closes: https://github.com/loongson-community/discussions/issues/102 Tested-by: Asiacn <710187964@qq.com> Signed-off-by: Xi Ruoyao Reviewed-by: Huacai Chen Reviewed-by: Alex Hung Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin --- drivers/gpu/drm/amd/display/dc/dml2/dml21/dml21_wrapper.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/gpu/drm/amd/display/dc/dml2/dml21/dml21_wrapper.c b/drivers/gpu/drm/amd/display/dc/dml2/dml21/dml21_wrapper.c index 03de3cf06ae59..059ede6ff2561 100644 --- a/drivers/gpu/drm/amd/display/dc/dml2/dml21/dml21_wrapper.c +++ b/drivers/gpu/drm/amd/display/dc/dml2/dml21/dml21_wrapper.c @@ -224,7 +224,9 @@ static bool dml21_mode_check_and_programming(const struct dc *in_dc, struct dc_s dml_ctx->config.svp_pstate.callbacks.release_phantom_streams_and_planes(in_dc, context); /* Populate stream, plane mappings and other fields in display config. */ + DC_FP_START(); result = dml21_map_dc_state_into_dml_display_cfg(in_dc, context, dml_ctx); + DC_FP_END(); if (!result) return false; @@ -279,7 +281,9 @@ static bool dml21_check_mode_support(const struct dc *in_dc, struct dc_state *co dml_ctx->config.svp_pstate.callbacks.release_phantom_streams_and_planes(in_dc, context); mode_support->dml2_instance = dml_init->dml2_instance; + DC_FP_START(); dml21_map_dc_state_into_dml_display_cfg(in_dc, context, dml_ctx); + DC_FP_END(); dml_ctx->v21.mode_programming.dml2_instance->scratch.build_mode_programming_locals.mode_programming_params.programming = dml_ctx->v21.mode_programming.programming; DC_FP_START(); is_supported = dml2_check_mode_supported(mode_support); -- 2.51.0