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 116232E737F for ; Mon, 5 Oct 2026 16:17:53 +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=1791217075; cv=none; b=YRB06vs+YhIk6BbGIGpDluEACfUc13HMl9I+Y0rWESDLu+W/d5bDvyMNIJaRww8QV4B+rb67GdokBUBwe52/JtKPoHR5zN42iSFtlcljvTQ1Ral5bV5OZ19mCZrZZ4sY/fixTUm36qCtChkSdvKUA0ztEIlvD5Z5NFWTbARnbls= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791217075; c=relaxed/simple; bh=3uHEZq/37PkZxn3U+9N1O6VeSqixASlANdImyn078hA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=On6wX+qB7XCmf1jI5U7TkpfyMkIFwiVuexhYtZIu7eSc7zMuXAM7LZ5VeAx7vfIpmIsG0j5XM2h8AVY4uEDIWwAofjlDdcfmp8d7E8JwYMv/vn1EziauSJ5pLOfycQUtR27mHq7p2XHbv3lBPej0HyPvhYp+upiwxlgpbivDDZA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=BpkbKdeU; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="BpkbKdeU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E1ABF1F000FF; Mon, 5 Oct 2026 16:17:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791217073; bh=hULtvVD1py9qQODCRmZPdnTQH/gEIAidu+T8iZjHZYo=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=BpkbKdeUlR4w9vxi1B+kmQv1y51U09TD78sSo/BaR4X67HOiwosupzm4K1ulDNxUf qRxhFj4AF8NvGQVuFexPW+MzG9XwBfksA+j1QtX7zTtbO2yjalhQVxFq6XBSOkU3yv E1F7zmSJ2Ar2446Sf7hzdxzMMJR6gYI70jbtDTjq2DicPfG8OziQqwVSdFaDOprJz9 lxdLYnhn2JQcTAIdkmHOXwOAhOUuhVJ/8aVBoXwxtHKDWB8ZvpUMch8zPYWhpEkzbJ YhyQAZcnecyrGdiahOS0fCWUm4kv8qMZtnD8WdWxGA5yn/pwfpl2Jlw4HztWVuDt8t UDSKExscUD6uQ== From: Sasha Levin To: stable@vger.kernel.org Cc: Arthur Heymans , George Zhang , Alex Hung , Dan Wheeler , Alex Deucher , Sasha Levin Subject: [PATCH 6.12.y] drm/amd/display: Preserve eDP mode on initial ASSR failure Date: Mon, 5 Oct 2026 12:17:48 -0400 Message-ID: <20261005161718.3002957-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026100541-wages-celibate-8917@gregkh> References: <2026100541-wages-celibate-8917@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Arthur Heymans [ Upstream commit 5e08102d1d336593160d1434261d50b0c0f6cbe6 ] Commit 56d8ce9d8c17 ("drm/amd/display: Apply correct panel mode when reinitializing hardware") made ASSR failure fall back to the default panel mode unless eDP mode had previously been applied. However, dc_link is zero-initialized and DP_PANEL_MODE_DEFAULT is zero. Before the first call to dp_set_panel_mode(), panel_mode therefore looks like a previously applied default mode. If ASSR setup fails during the first link training attempt, the driver incorrectly trains the eDP link using the default scrambling mode. On a Google Vilboz Chromebook running self-built coreboot firmware and PSP verstage, this leaves the panel mostly black with corrupted output along the top edge. Track whether panel_mode has actually been initialized, and only consult the saved mode after it has been applied. This retains the recovery behavior while preserving eDP mode during initial link training. Fixes: 56d8ce9d8c17 ("drm/amd/display: Apply correct panel mode when reinitializing hardware") Assisted-by: Pi:gpt-5.6-sol Reviewed-by: George Zhang Reviewed-by: Alex Hung Signed-off-by: Arthur Heymans Tested-by: Dan Wheeler Signed-off-by: Alex Deucher (cherry picked from commit ccb6c2702033f1002b45807fb3cc938760f26f78) Cc: stable@vger.kernel.org # 6.4.x [ sashal: Adjusted context for the different eDP panel-mode logging format. ] Signed-off-by: Sasha Levin --- drivers/gpu/drm/amd/display/dc/dc.h | 1 + .../amd/display/dc/link/protocols/link_edp_panel_control.c | 4 +++- 2 files changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/display/dc/dc.h b/drivers/gpu/drm/amd/display/dc/dc.h index a4f6ff7155c2a..f7cd6cb06638b 100644 --- a/drivers/gpu/drm/amd/display/dc/dc.h +++ b/drivers/gpu/drm/amd/display/dc/dc.h @@ -1721,6 +1721,7 @@ struct dc_link { struct ddc_service *ddc; enum dp_panel_mode panel_mode; + bool panel_mode_initialized; bool aux_mode; /* Private to DC core */ diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_edp_panel_control.c b/drivers/gpu/drm/amd/display/dc/link/protocols/link_edp_panel_control.c index fa642f4b88c2d..17220177479a3 100644 --- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_edp_panel_control.c +++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_edp_panel_control.c @@ -91,6 +91,7 @@ void dp_set_panel_mode(struct dc_link *link, enum dp_panel_mode panel_mode) } link->panel_mode = panel_mode; + link->panel_mode_initialized = true; DC_LOG_DETECTION_DP_CAPS("Link: %d eDP panel mode supported: %d " "eDP panel mode enabled: %d \n", link->link_index, @@ -1231,7 +1232,8 @@ void edp_set_panel_assr(struct dc_link *link, struct pipe_ctx *pipe_ctx, result = cp_psp->funcs.enable_assr(cp_psp->handle, link); - if (!result && link->panel_mode != DP_PANEL_MODE_EDP) + if (!result && link->panel_mode_initialized && + link->panel_mode != DP_PANEL_MODE_EDP) *panel_mode = DP_PANEL_MODE_DEFAULT; } } -- 2.53.0