From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4A460C5DF66 for ; Mon, 17 Aug 2026 11:52:29 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id C999210E773; Mon, 17 Aug 2026 11:52:28 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="CkSBZ7k9"; dkim-atps=neutral Received: from mail-pf1-f181.google.com (mail-pf1-f181.google.com [209.85.210.181]) by gabe.freedesktop.org (Postfix) with ESMTPS id 907BA10E0F8 for ; Sat, 15 Aug 2026 16:41:59 +0000 (UTC) Received: by mail-pf1-f181.google.com with SMTP id d2e1a72fcca58-84faf87d19dso2073492b3a.3 for ; Sat, 15 Aug 2026 09:41:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1786812119; x=1787416919; darn=lists.freedesktop.org; h=content-transfer-encoding:content-type:mime-version:message-id:date :subject:cc:to:from:from:to:cc:subject:date:message-id:reply-to :content-type; bh=B7syqqlv6107gB1yL3JYNqE/FxDJIWovYEa1sbJDV+M=; b=CkSBZ7k93cTL695Zy/LhesTrs2Kfeo6ct67Jf6BejyImkReQRygMKUSId4qPteznTG GItPw/ARx8e21c5ujM8wpLr9iKkZ0NnO+/8l0zSpeyE8mrZtHMtOk0M7uPoVCkH7hFMP wrecd+ckcYfwLbmwiqZ/j9J/Yhg8RdwQPN5tXR1XzFuIf1AkkIuOm/BWPGJGvMGiJBsA dgpNErpR1IfC634IqzJNNEYuJtnUha0yxG+oBNIExbPpnRT3Pbpf/ShD02khHrRaqNDh ZddDZavoMTc0Xn2d5PVRHCEJXmIimTdcH1jX5l6KDLN0+uO1FZLrSgVI8erZvvgAT6p4 4W/w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1786812119; x=1787416919; h=content-transfer-encoding:content-type:mime-version:message-id:date :subject:cc:to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject :date:message-id:reply-to:content-type; bh=B7syqqlv6107gB1yL3JYNqE/FxDJIWovYEa1sbJDV+M=; b=Bfg96zqwcGhLyU6FrtZKDeqFoyHAuMy5T2K5twlBqcdqj2oMwIHnwO6AUkkIefHhwx EOnf6GwCsOfPXkwsR1/bxsoy40zUuewoh7ocJ5H+de8o3YhxMZb6ZouSCCxT5u91q4cr 8Mi9dF28eK6E9+bDIQP/tHHS2P9YHCFYraB4+sE/Jptc1htsm2HzOlO6Cp+Y2oLg6Imu BNHo6M/MBwo/Y1OmRQBiBD+v1DaxsKQLerdPFIyN0AhGuz7wAmh3W9vRRFtAevFyW9OW a4xfla8+fhPzOKrDKcopxekUaqtwL1Uh5CiHwmu84iGeim3tKoSbZM675tr++QHT8Rbv rEUg== X-Gm-Message-State: AOJu0YxABvKVxMTYrgGRKP4daeTGGg0Tqtkv0pjMZH9IvRMCEZvX/uxQ SltEXCiDgdZF82CkhfJgLJ+WqONMfnw7OHZetYEtDjIUGukVnNwMBB9BsF3I9FUog+GOt26h X-Gm-Gg: AR+sD13z3Ed9PaLLPqY51kQW7j2RTYJQvWHYg28Af5vp6QM82Y21AbQBGnO3fuhfRnm /1AtgAsxnGDIQ1OKW9rrkQKuPIhOkW/yBMVr7px7X2XxiHv0L/1W46yFJVyKgSuvgQn+qLEIoMK oac9bPCwE6t1COD32k250vjhN/AHYFR/Kx1EObyX2/PGGYNPDlbW8g9HseaTNnwGXzUVzfGAnWV /eD2Lu2zf0dqVDiNqpZgl7J7DqWTjNkHpldcs7DYL6dZzmWoeqE8YrQMKGgsk/y2IwSp1gY4JNl AgjBk20zQ0Cf+5JsOkz4+RcBW12cOpWVFCCOLKpvu7Gxhy3e2zRQ3mfVE17/EW5oF43zGQ4ZXEW zuUkPOONlt9nRd+U9xkdAd98jdZxC0KUl6onrQF1lprD0GKOBOv+a8JY0XCkDUb5Wbrd9Se6Q6k b7YWQDHUGEWR5TowjNyHPTgPTv5xh009gDBTKF9nUpOv9a9nok4fAI3XCLfyajhZH/5d2U2xEEs acaDjsYcu4toG6TIPWzCw== X-Received: by 2002:a05:6a00:1810:b0:837:f79d:909 with SMTP id d2e1a72fcca58-84fde2defa1mr13881212b3a.39.1786812118931; Sat, 15 Aug 2026 09:41:58 -0700 (PDT) Received: from allen-xiaomibookpro14.lan ([2600:1900:4030:ad65:0:1::]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-8517d249c54sm1405086b3a.48.2026.08.15.09.41.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 15 Aug 2026 09:41:58 -0700 (PDT) From: =?UTF-8?q?Chang=20Jiong=28=E5=B8=B8=E7=82=AF=29?= To: intel-gfx@lists.freedesktop.org, intel-xe@lists.freedesktop.org Cc: dri-devel@lists.freedesktop.org, jani.nikula@linux.intel.com, rodrigo.vivi@intel.com, joonas.lahtinen@linux.intel.com, ville.syrjala@linux.intel.com, stable@vger.kernel.org, Chang Jiong Subject: [PATCH] drm/i915/cdclk: Don't force cd2x pipe select on Xe3 in bxt_sanitize_cdclk() Date: Sun, 16 Aug 2026 00:41:47 +0800 Message-ID: <20260815164149.607690-1-xspeed1989@gmail.com> X-Mailer: git-send-email 2.55.0 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Mailman-Approved-At: Mon, 17 Aug 2026 11:52:27 +0000 X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" Since commit 2ee8dbd880b1 ("drm/i915/cdclk: Fix up CDCLK_FREQ_DECIMAL without a full PLL re-enable") bxt_sanitize_cdclk() normalizes the CD2X pipe select field of the CDCLK_CTL readback to PIPE_NONE before comparing against the expected value. However bxt_cdclk_ctl() does not include the CD2X pipe select field at all on DISPLAY_VER() >= 30, so on Xe3 (PTL) the normalized readback (pipe field forced to the PIPE_NONE encoding, 0b111) can never match the expected value (pipe field 0). The comparison now fails on every boot and we always take the full CDCLK PLL disable+re-enable path with the BIOS framebuffer actively scanning out - exactly what this code was trying to avoid. On a Panther Lake laptop (Arc B390, 8086:b080, eDP 3120x2080@120) this causes "CPU pipe A FIFO underrun" during probe and persistent full-screen scanout corruption for the first KMS client (the SDDM greeter); the corruption lasts until the next full modeset. Only normalize the CD2X pipe select field on platforms where bxt_cdclk_ctl() actually programs it, mirroring its DISPLAY_VER() check. Fixes: 2ee8dbd880b1 ("drm/i915/cdclk: Fix up CDCLK_FREQ_DECIMAL without a full PLL re-enable") Cc: stable@vger.kernel.org Signed-off-by: Chang Jiong(常炯) --- drivers/gpu/drm/i915/display/intel_cdclk.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_cdclk.c b/drivers/gpu/drm/i915/display/intel_cdclk.c --- a/drivers/gpu/drm/i915/display/intel_cdclk.c +++ b/drivers/gpu/drm/i915/display/intel_cdclk.c @@ -2364,8 +2364,10 @@ static void bxt_sanitize_cdclk(struct intel_display *display) * dividers both syncing to an active pipe, or asynchronously * (PIPE_NONE). */ - cdctl &= ~bxt_cdclk_cd2x_pipe(display, INVALID_PIPE); - cdctl |= bxt_cdclk_cd2x_pipe(display, INVALID_PIPE); + if (DISPLAY_VER(display) < 30) { + cdctl &= ~bxt_cdclk_cd2x_pipe(display, INVALID_PIPE); + cdctl |= bxt_cdclk_cd2x_pipe(display, INVALID_PIPE); + } if (cdctl != expected) { if (DISPLAY_VER(display) < 20) {