From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=148.251.105.195 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793798798; b=os2EGUsNEjPsXvMi/Ik2Bn74NkI3JVysPoKlWipZnKVpVy1osw5nzOdpIOEq2/0u1eXC MIqOKosiUV9Cqs0vb5ULIO3r8GlZEdzWRAIl4+j7bSP6eciK76+L9817tfZ2qVoq/iDvU kfnHUTrk8liELu4jyOWmaTgL5266HnvfLqGBO+C9bKmwANqaqh8KxelnSHjjhbiDRNm2S pPzJg8fORqCxHFBeWolyOhLEhvZQyH340kQEFLjDQviuBj2cXWZQRNETO1qZvgtZK/ogu uMu4is40gU8ii209skpUrKc6cfTNdCC8/ZMVxg7CnbQfp1//U4c+Mu1FB7x41p4316g== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793798798; h=DMARC-Filter:DKIM-Signature:Received:From:Subject:Date:Message-Id: MIME-Version:Content-Type:Content-Transfer-Encoding:X-B4-Tracking: X-Change-ID:To:Cc:X-Mailer; bh=WaCxpE98IYBbY70Iwi5gktsAUiXJOLOOZ6R4uH9TCiI=; b=JcwxnEK8TxMRsMEeN+xzU5nnRuMrV9EpvOP40ce5j0xbrqFKDTXKssEBY9LU7waIAw7C lu3bkWyYUZno090ozSREfcitksq1U28FWOWtD3bJ4A2DF7toLD1xqjZG7hX6gl9twKTYi n4tASjbjH9q26KGS4ZqzjGk0v0ZHA+HyQgEXnf3Vi8sGcqsoAUKJndPSeMQvvtw59rOf2 geeZUHcjHcp7cVUYM/6eXe0JrKwVmibvEYR5pSaIfRhuqM86UgbwMdSqyxwRE/PQ/EOZh RQKu2rDTZBCOgXKv66c5hfysB+x2j+72VFT4wN8ri+7YuHLaQDyU03HNr0iSRziwYqA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=collabora.com; spf=pass smtp.mailfrom=collabora.com; dkim=pass header.d=collabora.com header.i=@collabora.com header.a=rsa-sha256 header.s=mail header.b=Mb0m5gtb; arc=none smtp.remote-ip=148.251.105.195 Received: from bali.collaboradmins.com (bali.collaboradmins.com [148.251.105.195]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4E8CE606D801 for ; Wed, 4 Nov 2026 13:26:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 4E8CE606D801 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 (2048-bit key, unprotected) header.d=collabora.com header.i=@collabora.com header.a=rsa-sha256 header.s=mail header.b=Mb0m5gtb DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1793798796; bh=tUdDEAiaFjRC4R52x7ZZpG/WNolxCCZdODmyMwbG+9Q=; h=From:Subject:Date:To:Cc:From; b=Mb0m5gtbQ8W0i1gG+Gi2VDmN5z0aJvx30GMeRXDr+Fu/8Op9WEtZw35HDirQRltmv KJ6AbntWfrJ19z7fRMvTpeUMz5Hqz/yulCrpB5LwH6QCF7NPW1vB7lMdawasRRMzQB D6Cb8bEd6DPspcA4P3+4ib2KpcCSrBg3SXEWrK5GzS+xJpRhUD8c0pww+okF965YTA 5FJnK4lWqSDJs4mPah+lFL/E/RZ8HwenhE1hI/NWHkKrISK5AG13s9Ah6KmeoV4UZa w7CTpHYazZfvIqOT9kk9FTpjaAlPsTr63zuUq7aKKCcQNQ655u54DNkVvNJ3a1a+hu mb40MwpvtgeZA== Received: from localhost (unknown [100.64.0.241]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange secp256r1 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: cristicc) by bali.collaboradmins.com (Postfix) with ESMTPSA id 26DA917E0163; Wed, 04 Nov 2026 14:26:36 +0100 (CET) From: Cristian Ciocaltea Subject: [PATCH 0/3] drm/display: hdmi: Fix SCDC scrambling corner cases Date: Wed, 04 Nov 2026 15:26:19 +0200 Message-Id: <20261104-hdmi-scdc-scramb-fixes-v1-0-16a9bb3d64a6@collabora.com> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-B4-Tracking: v=1; b=H4sIAAAAAAAC/yWMQQqDMBBFryKz7kASjYVeRbqIyagjaCXTiiDe3 aluPjw+7+0glJkEXsUOmVYW/swK9lFAHMLcE3JSBmdcba2pcEgTo8QUdXKYWux4I8GnN77ywZW 1KUHlJdN1qNu8b5ZfO1L8/mtwHCeHFBLYegAAAA== X-Change-ID: 20261104-hdmi-scdc-scramb-fixes-750545a23603 To: Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , =?utf-8?q?Ma=C3=ADra_Canal?= Cc: kernel@collabora.com, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Dan Carpenter , Sashiko X-Mailer: b4 0.15.2 This series fixes a few corner cases in the scrambling helpers introduced by commit d653818324ed ("drm/display: hdmi: Add HDMI 2.0 scrambling management helpers"). Patch 1 fixes a potential NULL pointer dereference in drm_connector_hdmi_sync_scdc() reported by Smatch. Patch 2 makes the SCDC resync logic rely on the committed state (scrambler_needed) rather than the source-side scrambler_enabled flag. The flag can be stale after a boot-time disable, which may cause a spurious CRTC reset and flicker on non-scrambled modes. Patch 3 ensures the sink's scrambling status is reset on non-scrambled modesets. Without this, a sink left scrambling by the firmware may never be cleared if the first modeset uses a mode below 340 MHz. The reset logic is factored into a common helper, which only writes to SCDC when bits are actually set. Signed-off-by: Cristian Ciocaltea --- Cristian Ciocaltea (3): drm/display: hdmi: Prevent NULL pointer dereference in sync_scdc() drm/display: hdmi: Use committed state to decide on SCDC resync drm/display: hdmi: Reset sink scrambling on non-scrambled modesets drivers/gpu/drm/display/drm_hdmi_helper.c | 65 ++++++++++++++++++++++++------- 1 file changed, 50 insertions(+), 15 deletions(-) --- base-commit: 6628e7d4c6b25c8d18f1345e3a20d21829aae7e4 change-id: 20261104-hdmi-scdc-scramb-fixes-750545a23603