From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C3762606A31A for ; Sun, 25 Oct 2026 13:48:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=bKA6LJlc Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 3858810E0E9; Sun, 25 Oct 2026 13:48:30 +0000 (UTC) Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by gabe.freedesktop.org (Postfix) with ESMTPS id 99F8110E0E9 for ; Sun, 25 Oct 2026 13:48:23 +0000 (UTC) Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id CFB93600CB; Sun, 25 Oct 2026 13:48:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 68AEB1F01825; Sun, 25 Oct 2026 13:48:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792936102; bh=u4nBrtlRd8CyKGRhGlajHs/dIr69w/JMdhoO/IZ0tKI=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=bKA6LJlcha62NxQSUifaUbtYxWJPLbFuq4xQOsuyaKI+X920e/hokhXLqiY72d0p+ jm5QI+KtTmGCWmYVuM4xKLgy2DPL94L3pqqAuZOP7j3mbTGPrhzYhxvmAROmtpKHrX BVXPGVYWOvAiO8mAUpJbFDTdba1bqf25ruydra0WJpz3w+VQDMHWFfJ+fYNSyJYuLZ HQUmjotySXbQRu2sfyig9NKgKsBn0+A43ZdHmpHY6bHhVM32XmjL1KFXxUeD+Qgtpv r8CSyKGoEQIAJKeNpfZ0bvJnghbCrqkkHfbG7ypPKDVAceEnhWPWGkOeH1h9AKUWa5 EFO/kKifHo+xw== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v1] drm/bridge: ssd2825: Fix panel enable sequence To: "Svyatoslav Ryhel" Cc: dri-devel@lists.freedesktop.org In-Reply-To: <20261025133636.253505-1-clamor95@gmail.com> References: <20261025133636.253505-1-clamor95@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Sun, 25 Oct 2026 13:48:21 +0000 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: sashiko-reviews@lists.linux.dev Sender: "dri-devel" X-Spam-Status: No, score=-11.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 X-Archived-By: Thank you for your contribution! Sashiko AI review found 1 potential issue(= s) to consider: - [Medium] drm/bridge: ssd2825: duplicate atomic_enable() call on next_brid= ge -- commit 1c5e404afec7538a0e06a870cc1167b8db336814 Author: Svyatoslav Ryhel drm/bridge: ssd2825: Fix panel enable sequence This commit invokes the next bridge's atomic_enable() callback directly at the end of ssd2825_bridge_atomic_pre_enable() to restore panel output after commit 554d36acf5e0 removed direct panel handling. > diff --git a/drivers/gpu/drm/bridge/ssd2825.c b/drivers/gpu/drm/bridge/ss= d2825.c > index 71877699dfab6..9216cee09115f 100644 > --- a/drivers/gpu/drm/bridge/ssd2825.c > +++ b/drivers/gpu/drm/bridge/ssd2825.c > @@ -475,6 +475,7 @@ static void ssd2825_bridge_atomic_pre_enable(struct d= rm_bridge *bridge, > struct drm_atomic_commit *state) > { > struct ssd2825_priv *priv =3D bridge_to_ssd2825(bridge); > + struct drm_bridge *next_bridge =3D priv->output.bridge; > struct mipi_dsi_device *dsi_dev =3D priv->output.dev; > const struct drm_crtc_state *crtc_state; > const struct drm_display_mode *mode; > @@ -569,6 +570,14 @@ static void ssd2825_bridge_atomic_pre_enable(struct = drm_bridge *bridge, > /* Initial DSI configuration register set */ > ssd2825_write_reg(priv, SSD2825_CONFIGURATION_REG, config); > ssd2825_write_reg(priv, SSD2825_VC_CTRL_REG, 0); > + > + /* > + * The SSD2825 requires that the next bridge be enabled first; > + * otherwise, the SSD2825 cannot complete its configuration and > + * there will be no output. > + */ > + if (next_bridge->funcs && next_bridge->funcs->atomic_enable) > + next_bridge->funcs->atomic_enable(next_bridge, state); [Severity: Medium] Does calling next_bridge->funcs->atomic_enable() directly in ssd2825_bridge_atomic_pre_enable() cause next_bridge->funcs->atomic_enable() to be invoked twice on every modeset enable? In drivers/gpu/drm/bridge/ssd2825.c, ssd2825_bridge_attach() attaches priv->output.bridge to the encoder's bridge chain: return drm_bridge_attach(bridge->encoder, priv->output.bridge, bridge, flags); During an atomic modeset enable, drm_atomic_helper_commit_modeset_enables() runs drm_atomic_bridge_chain_pre_enable(), which calls ssd2825_bridge_atomic_pre_enable() and now invokes next_bridge->funcs->atomic_enable() for the first time. Immediately afterwards, drm_atomic_helper_commit_encoder_bridge_enable() calls drm_atomic_bridge_chain_enable() in drivers/gpu/drm/drm_bridge.c: drm_for_each_bridge_in_chain_from(first_bridge, bridge) if (bridge->funcs->atomic_enable) bridge->funcs->atomic_enable(bridge, state); This calls next_bridge->funcs->atomic_enable() a second time while drm_atomic_bridge_chain_disable() only calls atomic_disable() once. When next_bridge is a panel bridge, panel_bridge_atomic_enable() calls drm_panel_enable() in drivers/gpu/drm/drm_panel.c, where the second call hi= ts the already-enabled check and emits a warning on every modeset: if (panel->enabled) { dev_warn(panel->dev, "Skipping enable of already enabled panel\n"); return; } When next_bridge is a non-panel drm_bridge, there is no enabled-state guard in the DRM bridge core, so next_bridge->funcs->atomic_enable() runs twice without a matching second disable. Additionally, if next_bridge sets pre_enable_prev_first, drm_atomic_bridge_chain_pre_enable() runs ssd2825_bridge_atomic_pre_enable() before next_bridge->funcs->atomic_pre_enable(), which would cause next_bridge->funcs->atomic_enable() to run before next_bridge has been prepared in atomic_pre_enable(). --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261025133636.2535= 05-1-clamor95@gmail.com?part=3D1