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 53795C43458 for ; Mon, 6 Jul 2026 19:43:40 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id B8E0A10EA9E; Mon, 6 Jul 2026 19:43:39 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="CA5ly8zC"; dkim-atps=neutral Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by gabe.freedesktop.org (Postfix) with ESMTPS id 1404A10EA9E for ; Mon, 6 Jul 2026 19:43:39 +0000 (UTC) Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id D481740F1C; Mon, 6 Jul 2026 19:43:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 68D871F000E9; Mon, 6 Jul 2026 19:43:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783367018; bh=LpYBDzzTpttvxZ5Prf6UTUzPZ6dzUGSbel8XI7kLx+c=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=CA5ly8zCxElI0S9SwfsRdKOPley0dGdAR4UN/USh7CXrLnT7DufZzWgpPo4f3VBwT oEoXXCQhH0IkSuVMGO3+zLxy37q6dTyt1SxU8ta6wGhmQKk6tsOpWucJiww8fvwWn8 q7nBJnQDRLGC3XxVcyxPC1i/k8x0XgunsaUK7WFFOZ2HmnQ/ro3qdMZu328lsbPI9d DW22fhWhkAyExxKGm+qO+PV2ysz+ehLCLgme+UOEfjYXTPDURMBBGLdDX+R2eGSISY ejY4Chzb6siLy+GfhGG1P+kS15rCgAmvXIBreSeuK2l6FNPUDfPV33CZd6FZ+xavAk q/B6AzlWL/FGg== From: sashiko-bot@kernel.org Subject: Re: [PATCH v2 11/13] drm/rockchip: dw_hdmi_qp: Support 10-bit YUV422 output format To: "Cristian Ciocaltea" Cc: robh@kernel.org, conor+dt@kernel.org, devicetree@vger.kernel.org, dri-devel@lists.freedesktop.org In-Reply-To: <20260706-dw-hdmi-qp-yuv-v2-11-b91beb33dedf@collabora.com> References: <20260706-dw-hdmi-qp-yuv-v2-0-b91beb33dedf@collabora.com> <20260706-dw-hdmi-qp-yuv-v2-11-b91beb33dedf@collabora.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Mon, 06 Jul 2026 19:43:37 +0000 Message-Id: <20260706194338.68D871F000E9@smtp.kernel.org> X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: sashiko-reviews@lists.linux.dev Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Thank you for your contribution! Sashiko AI review found 1 potential issue(= s) to consider: Pre-existing issues: - [High] The `atomic_check` callback incorrectly modifies driver private ha= rdware state (`hdmi->tmds_char_rate`) and invokes PHY configuration functio= ns (`phy_configure`), violating the stateless nature of atomic checks. -- commit 6a5a6d9518ed6863c0bd7d0093aee570c295458a Author: Cristian Ciocaltea drm/rockchip: dw_hdmi_qp: Support 10-bit YUV422 output format This commit adds support for 10-bit YUV 4:2:2 output to the DW HDMI QP encoder by configuring the PHY with 8 bpc when YUV 4:2:2 is in use. This keeps the output clock aligned with the TMDS character rate. > diff --git a/drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c b/drivers/gpu= /drm/rockchip/dw_hdmi_qp-rockchip.c > index 9c4cf68d79d50..78473f9a0fce3 100644 > --- a/drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c > +++ b/drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c > @@ -215,6 +215,7 @@ dw_hdmi_qp_rockchip_encoder_atomic_check(struct drm_e= ncoder *encoder, > s->output_mode =3D ROCKCHIP_OUT_MODE_AAAA; > break; > case MEDIA_BUS_FMT_UYVY8_1X16: > + case MEDIA_BUS_FMT_UYVY10_1X20: > s->output_mode =3D ROCKCHIP_OUT_MODE_YUV422; > break; > case MEDIA_BUS_FMT_UYYVYY8_0_5X24: > @@ -226,7 +227,14 @@ dw_hdmi_qp_rockchip_encoder_atomic_check(struct drm_= encoder *encoder, > } > =20 > phy_cfg.hdmi.tmds_char_rate =3D conn_state->hdmi.tmds_char_rate; > - phy_cfg.hdmi.bpc =3D conn_state->hdmi.output_bpc; > + /* > + * YUV422 always transmits two 12-bit components per clock cycle, > + * regardless of the color depth, which from a rate perspective is > + * equivalent to three 8-bit RGB components. Force 8 bpc here to > + * keep the PHY PLL output aligned with the TMDS character rate. > + */ > + phy_cfg.hdmi.bpc =3D (s->output_mode =3D=3D ROCKCHIP_OUT_MODE_YUV422 ? > + 8 : conn_state->hdmi.output_bpc); > =20 > ret =3D phy_configure(hdmi->phy, &phy_cfg); > if (!ret) { > hdmi->tmds_char_rate =3D conn_state->hdmi.tmds_char_rate; [Severity: High] This isn't a bug introduced by this patch, but does this violate the DRM atomic API contract? Modifying physical PHY hardware state and persistent driver state (hdmi->tmds_char_rate) during the stateless atomic check phase could cause problems if userspace issues a test-only atomic commit. If a compositor issues DRM_MODE_ATOMIC_TEST_ONLY, phy_configure() will prog= ram the PHY hardware and hdmi->tmds_char_rate will be mutated. When the test-on= ly commit is discarded, the PHY is left in an unexpected state. A subsequent real commit might then hit the fast-path check earlier in this function: if (hdmi->tmds_char_rate =3D=3D conn_state->hdmi.tmds_char_rate && s->output_bpc =3D=3D conn_state->hdmi.output_bpc && s->bus_format =3D=3D ingest_fmt) return 0; and skip PHY configuration entirely, leaving the hardware incorrectly configured. Could this lead to hardware misconfiguration, visual glitches, or black screens? > s->output_type =3D DRM_MODE_CONNECTOR_HDMIA; > s->output_bpc =3D conn_state->hdmi.output_bpc; > s->bus_format =3D ingest_fmt; --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260706-dw-hdmi-qp= -yuv-v2-0-b91beb33dedf@collabora.com?part=3D11