From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sender4-pp-f112.zoho.com (sender4-pp-f112.zoho.com [136.143.188.112]) (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 16E5E3A544C for ; Fri, 19 Jun 2026 14:38:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=pass smtp.client-ip=136.143.188.112 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781879889; cv=pass; b=B8KIXDPYatBpGzjm7kIroJGwkwkHCJZfb326HVNvoqLskb6WaYUYz5EAwfuVA7JzDFR4r0+vAc1pMD/PNLAO24xvEljOOzbAKErDIAF0/Vr3MFsjj2xnoAZkQklly3T0DFtEOipXWzJBGkNTnoulhiNPVl9pP86bElXNQX7aIi4= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781879889; c=relaxed/simple; bh=0iTCuP3EP0RJf2jFGq8eSvPhrPQJJ1aQBybeT5HaqJg=; h=From:Subject:Date:Message-Id:MIME-Version:Content-Type:To:Cc; b=NThWczRsQYeRMvjcIiqmH7MP7zIDg+azfUwaTaR8TzZvqyK+v8bxyUIzTocgg8TCafdpJ6trEk06bXLPm66KQJwozFGGwiffuhMlwwYiZ7yn+hU5fQkMBJXJo6M5PjDPLtrP3dzi4RSO+HEkomLr63XjnVic4T4SAUVn5Aa6c00= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com; spf=pass smtp.mailfrom=collabora.com; dkim=pass (1024-bit key) header.d=collabora.com header.i=nicolas.frattaroli@collabora.com header.b=QtvHlDZ0; arc=pass smtp.client-ip=136.143.188.112 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=collabora.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=collabora.com header.i=nicolas.frattaroli@collabora.com header.b="QtvHlDZ0" ARC-Seal: i=1; a=rsa-sha256; t=1781879869; cv=none; d=zohomail.com; s=zohoarc; b=OUtwSNEJFuvmSfrwkWjNYckDjst0V7QawAm8jjQlT6py+5BGIRLgFmq6nX5uIaGExMMXcHkDYJBbqAWALOBYGiJnzjr3SLAUcY01vXTHCDJ32MKCN5j/5HgfF6cfPhPXwebCmvgjRMmgYCR4MV1/2zkQSzFJXrXoeE8ipkTifNo= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1781879869; h=Content-Type:Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:MIME-Version:Message-ID:Subject:Subject:To:To:Message-Id:Reply-To; bh=HPAcmv5SV6s4wALviuzPUJ+LE7njy+FJJeynX4WM3LE=; b=gIYve93jWicei8/r3ehU92QJHncq+8RIvDkMEXPdUkJsVgaXpAMj3Qyb3PweIiLw3/+USpsu7XZb3+v8RvSdthgBd5Qy/WG+0mp0OTBpWE3pUXDFsW1LiMYO6MCXXpBrkLl22zDUBZ8iC0Ms1yU4hgMHxeoeFi5IK4Eel71heU0= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass header.i=collabora.com; spf=pass smtp.mailfrom=nicolas.frattaroli@collabora.com; dmarc=pass header.from= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1781879869; s=zohomail; d=collabora.com; i=nicolas.frattaroli@collabora.com; h=From:From:Subject:Subject:Date:Date:Message-Id:Message-Id:MIME-Version:Content-Type:Content-Transfer-Encoding:To:To:Cc:Cc:Reply-To; bh=HPAcmv5SV6s4wALviuzPUJ+LE7njy+FJJeynX4WM3LE=; b=QtvHlDZ0h88sqWkUUKnyLRzKS2UXmmGh6KthK0Q/eVpV2VpcVqDQ84KI+Vt8GsWI P5vzqCByqsF6pbuDy3es6327uyKLYXVc6K1z/hbq/p9P8U0XOnBFZO7FaywWv79PELN xUqJIUAoeaCsWR0ruwJFGdO2yt7lkIDwZsJWhF2Y= Received: by mx.zohomail.com with SMTPS id 1781879868420866.2259164179989; Fri, 19 Jun 2026 07:37:48 -0700 (PDT) From: Nicolas Frattaroli Subject: [PATCH v3 0/2] Make HDMI state helpers handle odd max bpc requests Date: Fri, 19 Jun 2026 16:37:30 +0200 Message-Id: <20260619-hdmi-max-bpc-fix-v3-0-ba83e5361eb0@collabora.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-B4-Tracking: v=1; b=H4sIAAAAAAAC/3WOwW7CMBBEfyXyuds6TmQHTv2PioO9WchWGAfbR CCUf68JHBCip9WsZt7MVSSKTEmsq6uINHHicCii+agEDvawI+C+aKGk0lLLDobeM3h7BjcibPk MRjayXhnddE0rSmyMVN4L8mdz1+nkfgnzjfNwRDqeSle+24SziQCD95zXVR89ZB6/HlfcIAOnH OJlmTnVS+b/RVMNEjR1PZJDo0z7jWG/ty5E+1lKFuCkniD1O4gqEOO02bbdyknEV8g8z3/Konk 0PgEAAA== X-Change-ID: 20260608-hdmi-max-bpc-fix-703019763834 To: Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Dmitry Baryshkov Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, kernel@collabora.com, Nicolas Frattaroli X-Mailer: b4 0.15.2 With the "max bpc" KMS connector property, userspace can arbitrarily restrict the upper end of the bits-per-component range. This is fine and good, except the HDMI state helpers never considered that max_bpc could be influenced by a userspace setting, so assumed it'll always be an even value from the HDMI standards. This, unfortunately, is not the world we live in anymore. Patch 1 corrects sink_supports_format_bpc to return false on BPCs outside of what HDMI allows. Patch 2 then corrects handling of odd-numbered max bpcs by rounding the loop start value down to an even number instead. It also adds a KUnit test to make sure nobody breaks this again in the future. Signed-off-by: Nicolas Frattaroli --- Changes in v3: - Move bpc check before vic check, and show debug message on failure - Link to v2: https://patch.msgid.link/20260618-hdmi-max-bpc-fix-v2-0-7b67f489b0cc@collabora.com Changes in v2: - Use rounddown() from linux/math.h instead of the bespoke rounding. No functional changes. - Note: switch statement in patch 1 kept as-is, as 14bpc is not allowed by HDMI it seems. - Link to v1: https://patch.msgid.link/20260608-hdmi-max-bpc-fix-v1-0-6e8dcebc7274@collabora.com --- Nicolas Frattaroli (2): drm/display: hdmi: Only allow BPC values of 8, 10, 12 and 16 drm/display: hdmi: Round odd max_bpc down to even numbers drivers/gpu/drm/display/drm_hdmi_state_helper.c | 13 +++- drivers/gpu/drm/tests/drm_hdmi_state_helper_test.c | 71 ++++++++++++++++++++++ 2 files changed, 83 insertions(+), 1 deletion(-) --- base-commit: 24209d838338d162bb25aadfd637b11747a357ca change-id: 20260608-hdmi-max-bpc-fix-703019763834 Best regards, -- Nicolas Frattaroli