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 72F30CD37AC for ; Mon, 11 May 2026 14:40:36 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id DD05510E797; Mon, 11 May 2026 14:40:35 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="GqZXOw6o"; dkim-atps=neutral Received: from mail-ot1-f41.google.com (mail-ot1-f41.google.com [209.85.210.41]) by gabe.freedesktop.org (Postfix) with ESMTPS id 303E110E101 for ; Sat, 9 May 2026 16:24:26 +0000 (UTC) Received: by mail-ot1-f41.google.com with SMTP id 46e09a7af769-7dbcb45153cso209931a34.3 for ; Sat, 09 May 2026 09:24:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1778343865; x=1778948665; darn=lists.freedesktop.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=LO2P0xIyQDisD90PKW6kTEf7ozKUuDCN/MlNOVEwtA8=; b=GqZXOw6oXghP0yIrow/tU24BgNnJyQXl+7h1EJHsugVbpI802zf1C+53cbwCAgTa7w r40ua542vETZ3WwwdTlgc8sP8CYQafyflucoNp6B9G8C2MjMEwlvke3Icz4Pc8jGoFwP k3KYuJIsa38gxqbrJNxJ68qFXz6MWWGUAM570glqJHzaKUpUS5og/uRNowXREq4Zhzmh LJxm1uIf4ndADEdUapWPUqVRFYb5rN9+PYqnRdvUIUD+46pjLhGTw6gaTHaXzmZeirrj 90su9JlTGOqRqabb3KH7XAHErJafSNDX10GSoknhvUJrLIZn5q+dBRhBOXuQcJa2vWta YIRQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1778343865; x=1778948665; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=LO2P0xIyQDisD90PKW6kTEf7ozKUuDCN/MlNOVEwtA8=; b=KxXQZ5UYZPADQPROLZQ+EFuiuRf97zxjmwi2Na6IVIjLSYya1OTMxP1Nbx8OK50537 7eyQyNhbGlWnURwe0wVKiqQfN/KhwLsf41wR2Y+eofSqs0s192IUSJXe85JsLU0fCslj KRT2Ki7KySrY1jInSl95HIQf11JoEBlpDyRYfxfo43uglzlkDDhRNLaIA4L0no6N9Q+C K+D5QxGe7ISRErqBWebz+p+XA+9PLZhxQetF/Pu1lp8n5OaZPXQCxkXXXNQ9Lhsqu+2l rmGPetmN5eZK/4wv/uQAQMwAvz1sW+FuNtBgWY/bTkDzT0VWGiQs3FDnAm8JiJZT6GIC TkxQ== X-Gm-Message-State: AOJu0YzMiy45G1aYy/dpt0BCPMvDy/A3WTsifHZ8WY8zB8120gKA9jgR G/5BfW4z+rdGdAhTB07yC+u44YKiUwbvxVpy0z5Dlir9jEuTnLmiz2tu1VrbEV/jtuk= X-Gm-Gg: Acq92OEIgyTOWCgUXu42rd4Iw1O+na7bzlgVV6kqBjTcdkrm4qDgh1CEGiinQ4O9rpb /AUMssOWi+TpH938i5fdaOjTLuvcTLIuXf1zn5aA40miH1xVMFGE6C/Deb4q9uT7TS70WTv+bP2 Wx5d0rJg4fycEZzG8Cm6z5XRRlqAKYjtTLPOQcSKzq1E4MfDyIPm86z03ViBtPtXqrSJDZ2uAbX 4bUIVbtycxgdDrfI5Z9iiYRsNDfLiEFhDfHzHcQMWMfKrV89nEB9SGby6Ivi590eZri4pFrHfDW 21PpaTNqEWTySqB1zhW0vpX5mzE5kcSKx0QAAEsfkeGbHOsaPLv4x12iYGJbznihtbC6kMhSKaE h3eFiq0LsSIwxFmdWO0AfyCCshzkIuS84F61l8aE8J4VuSH+lyGa1oMcxdanSOoQWG21Z5MzfSl hcrKySHJpKsnuOFfggDchmLmHsMjpbaJjy8KWtoVs2M7dcLUpsYnbGj9LM7WWkAebgafA1EzyiX TvZ9Fji9v+eiZharlK2aEB0 X-Received: by 2002:a05:6870:fbac:b0:434:357:6dcd with SMTP id 586e51a60fabf-434fc418c5amr6222410fac.8.1778343865106; Sat, 09 May 2026 09:24:25 -0700 (PDT) Received: from localhost ([136.49.184.116]) by smtp.gmail.com with ESMTPSA id 586e51a60fabf-435571099a4sm4623244fac.7.2026.05.09.09.24.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 09 May 2026 09:24:24 -0700 (PDT) From: Aaron Esau To: intel-gfx@lists.freedesktop.org Cc: intel-xe@lists.freedesktop.org, dri-devel@lists.freedesktop.org, jani.nikula@linux.intel.com, rodrigo.vivi@intel.com, joonas.lahtinen@linux.intel.com, tursulin@ursulin.net, mika.kahola@intel.com, stable@vger.kernel.org, Aaron Esau Subject: [PATCH 1/3] drm/i915/cx0: check PLL ACK bit in intel_cx0_pll_is_enabled() Date: Sat, 9 May 2026 11:24:05 -0500 Message-ID: <20260509162407.510539-2-aaron1esau@gmail.com> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260509162407.510539-1-aaron1esau@gmail.com> References: <20260509162407.510539-1-aaron1esau@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Mailman-Approved-At: Mon, 11 May 2026 14:40:35 +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" intel_cx0_pll_is_enabled() only checks the PCLK_PLL_REQUEST bit in PORT_CLOCK_CTL, which is set by the driver during the PLL enable sequence. It does not check the PCLK_PLL_ACK bit, which is the hardware's response indicating the PLL actually locked. When the CX0 PHY MSGBUS is unresponsive (e.g. after a failed s2idle resume), the PLL register programming via MSGBUS silently fails and the PLL never locks, but intel_cx0_pll_is_enabled() returns true because the driver-set REQUEST bit is present. This causes all downstream state readout and verification to operate on a PLL that is not actually enabled. Check both the REQUEST and ACK bits so that a PLL is only reported as enabled when the hardware has confirmed it locked. Fixes: bf8531990380 ("drm/i915/display: Allow display PHYs to reset power state") Cc: stable@vger.kernel.org Cc: Mika Kahola Signed-off-by: Aaron Esau --- drivers/gpu/drm/i915/display/intel_cx0_phy.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_cx0_phy.c b/drivers/gpu/drm/i915/display/intel_cx0_phy.c index 7288065d2..4cacea802 100644 --- a/drivers/gpu/drm/i915/display/intel_cx0_phy.c +++ b/drivers/gpu/drm/i915/display/intel_cx0_phy.c @@ -3581,9 +3581,12 @@ static bool intel_cx0_pll_is_enabled(struct intel_encoder *encoder) struct intel_display *display = to_intel_display(encoder); struct intel_digital_port *dig_port = enc_to_dig_port(encoder); u8 lane = dig_port->lane_reversal ? INTEL_CX0_LANE1 : INTEL_CX0_LANE0; + u32 val; - return intel_de_read(display, XELPDP_PORT_CLOCK_CTL(display, encoder->port)) & - intel_cx0_get_pclk_pll_request(lane); + val = intel_de_read(display, XELPDP_PORT_CLOCK_CTL(display, encoder->port)); + + return (val & intel_cx0_get_pclk_pll_request(lane)) && + (val & intel_cx0_get_pclk_pll_ack(lane)); } void intel_mtl_tbt_pll_disable_clock(struct intel_encoder *encoder) -- 2.54.0