From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 5A4FF2D94B5 for ; Wed, 20 May 2026 14:37:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779287839; cv=none; b=ICrtSSxfCgnjks1Z/lXALLwrJSnsXC91irQeNjAckdRWqzKtWOx6jIeQUIR8rQxDWby+ikyDyXSNH4lR/gBajVIVwc9wTy3YvvpVqE530hExDwkobFrHizVwmbOlY7jGPhMgxCtWD+Tw4791YIc/trAVtaZcKPV0cTLS0jsPA0s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779287839; c=relaxed/simple; bh=Dmzl1wREm0iyX9rEshZio5d2Ho5v2f9hfNS9sNx3PGI=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=cxOr6MChtnWCIGCLswdG5vvn2xMQoOB0808DUqKPqtItm7+N8J0Q4+EbPb+2jrCW0Eeg+Zj7z8lHgL4Z/PD5JDqyQTDD/3mDfBjTQoVqqlqzp4061XuqOjc6n9eUEy0UgfHSF5oe1kNIdKUTc6yZN2C7mV6lEs5GuvjXnpNuGqA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=DYa234E1; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="DYa234E1" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5A9031F000E9; Wed, 20 May 2026 14:37:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1779287837; bh=/IanGkJ/5bVNKs2Vf2y9RHBi8rga8aiTHVhmqqD4XEQ=; h=Subject:To:Cc:From:Date; b=DYa234E1CZOfLhXu54PBUMs8wlH17oUP+j5Yun9JFD5nJsOua5vofZ9k92fwoTkwX Jyowd0hdw8d2xr37cxlhrRjAiIvHwchF6N1NjsbMVYt3IOmjcN4boPKUgo6YByXBDs MYnltZz72RIKDuz5KC1M/wXNQY4+/mqEZQKvcKLg= Subject: FAILED: patch "[PATCH] drm/amd/display: Wrap DCN32 phantom-plane allocation in" failed to apply to 6.6-stable tree To: mikhail.v.gavrilov@gmail.com,alexander.deucher@amd.com,aurabindo.pillai@amd.com,daniel.wheeler@amd.com,pinglei.lin@amd.com Cc: From: Date: Wed, 20 May 2026 16:37:10 +0200 Message-ID: <2026052010-oppressor-germless-5b29@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 183182235f6d53bac62c6c39014738a54a68dfa6 # git commit -s git send-email --to '' --in-reply-to '2026052010-oppressor-germless-5b29@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 183182235f6d53bac62c6c39014738a54a68dfa6 Mon Sep 17 00:00:00 2001 From: Mikhail Gavrilov Date: Tue, 5 May 2026 09:05:37 +0800 Subject: [PATCH] drm/amd/display: Wrap DCN32 phantom-plane allocation in DC_RUN_WITH_PREEMPTION_ENABLED [Why] dcn32_validate_bandwidth() wraps dcn32_internal_validate_bw() with DC_FP_START()/DC_FP_END(). In x86 non-RT, DC_FP_START takes fpregs_lock(), which disables local softirqs. The DML1 path through dcn32_enable_phantom_plane() calls kvzalloc() to allocate ~335 KiB for dc_plane_state. This triggers the vmalloc path, which calls BUG_ON(in_interrupt()) because it's invoked within the FPU-enabled (softirq disabled) region, leading to a kernel crash. [How] Wrap the dc_state_create_phantom_plane() call with the DC_RUN_WITH_PREEMPTION_ENABLED() macro to allow preemption during this memory allocation. Fixes: 235c67634230 ("drm/amd/display: add DCN32/321 specific files for Display Core") Closes: https://gitlab.freedesktop.org/drm/amd/-/work_items/4470 Reviewed-by: Aurabindo Pillai Signed-off-by: Mikhail Gavrilov Signed-off-by: James Lin Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher (cherry picked from commit 885ccbef7b94a8b38f69c4211c679021aa27ad11) Cc: stable@vger.kernel.org diff --git a/drivers/gpu/drm/amd/display/dc/resource/dcn32/dcn32_resource.c b/drivers/gpu/drm/amd/display/dc/resource/dcn32/dcn32_resource.c index 82f81b586986..3751f7a94a05 100644 --- a/drivers/gpu/drm/amd/display/dc/resource/dcn32/dcn32_resource.c +++ b/drivers/gpu/drm/amd/display/dc/resource/dcn32/dcn32_resource.c @@ -92,9 +92,14 @@ #include "dml/dcn32/dcn32_fpu.h" #include "dc_state_priv.h" +#include "dc_fpu.h" #include "dml2_0/dml2_wrapper.h" +#if !defined(DC_RUN_WITH_PREEMPTION_ENABLED) +#define DC_RUN_WITH_PREEMPTION_ENABLED(code) code +#endif + #define DC_LOGGER_INIT(logger) enum dcn32_clk_src_array_id { @@ -1684,7 +1689,8 @@ static void dcn32_enable_phantom_plane(struct dc *dc, if (curr_pipe->top_pipe && curr_pipe->top_pipe->plane_state == curr_pipe->plane_state) phantom_plane = prev_phantom_plane; else - phantom_plane = dc_state_create_phantom_plane(dc, context, curr_pipe->plane_state); + DC_RUN_WITH_PREEMPTION_ENABLED(phantom_plane = + dc_state_create_phantom_plane(dc, context, curr_pipe->plane_state)); if (!phantom_plane) continue;