From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0115B257429; Sun, 1 Jun 2025 23:24:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748820283; cv=none; b=jYCFthHomjW323TYdJ2Xbu7F682OQ/KHmDhc80Ptwloeqbr9hNfImZFLlmClLOVy9RE4vzLaDDK4DKcZXqK6LzJ5qtP5pjGfu9aWpw05DZ71VRl/n+m5uMHVmsim09xcvDIx+lHGz8CFSC5LJGUevT/la13gCRC4677s6n4PXjY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748820283; c=relaxed/simple; bh=FvoF4yjt+VixD0Lh1JUNXrpy8vAcNwCKA5aOdeHYRTI=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=Ru5EyiiN9RGB2A5Cq0y1nwOARO9A1J6eKj6prphLxcqHBmxdb3z6b+QIKgSEqQRFVG1GQX9jNLkvLfAE5sw3ml7RAkBys20q4Z9jhuJiGJXSDbUYd+elU9LEiRN+V7FkAC0k4fsnWLNcw5JEYAbVmg3RB0JLkGGTNBp1ZpGhJuI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=A1H9eP03; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="A1H9eP03" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F2A99C4CEF2; Sun, 1 Jun 2025 23:24:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1748820281; bh=FvoF4yjt+VixD0Lh1JUNXrpy8vAcNwCKA5aOdeHYRTI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=A1H9eP03MTtR7XTI1H0TXXjrSaIWhqzpXdYmKdK+C7oY7khWEnddCE7ZTJ8koGxfR B0XT1IrjOZ980ZJczhK6LFs+3QMLSIGmbiy2A19oFyehReh2n6qTQE4YZpa3Y8pJBM vq+CKrD5d+NHwKsltzcLAjmIqbSENPbeM4VipUgnn4kG+40KwtLmfCEtpn6pcInJrh 4fV4laQQ9Rm9sb1bpflqc2Tfcd8kDPBRGsKDJVLC17/EjPmXv5QFKU/QdaAoU3Cf1w lW/mcJruL2+rr2QoV4LZi70w5RyKaNgtjp2+XAjH8V/JejjLybc2VYZjgxtUvhC8MU iGQI5uAZbNM8A== From: Sasha Levin To: patches@lists.linux.dev, stable@vger.kernel.org Cc: Dmitry Baryshkov , Neil Armstrong , Sasha Levin , andrzej.hajda@intel.com, rfoss@kernel.org, maarten.lankhorst@linux.intel.com, mripard@kernel.org, tzimmermann@suse.de, airlied@gmail.com, simona@ffwll.ch, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: [PATCH AUTOSEL 6.15 002/110] drm/bridge: select DRM_KMS_HELPER for AUX_BRIDGE Date: Sun, 1 Jun 2025 19:22:44 -0400 Message-Id: <20250601232435.3507697-2-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250601232435.3507697-1-sashal@kernel.org> References: <20250601232435.3507697-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.15 Content-Transfer-Encoding: 8bit From: Dmitry Baryshkov [ Upstream commit b12fa5e76e1463fc5a196f2717040e4564e184b6 ] The aux bridge uses devm_drm_of_get_bridge() from the panel bridge (and correctly selects DRM_PANEL_BRIDGE). However panel bridge is not a separate module, it is compiled into the drm_kms_helper.o. Select DRM_KMS_HELPER too to express this dependency. Reviewed-by: Neil Armstrong Link: https://lore.kernel.org/r/20250411-aux-select-kms-v1-1-c4276f905a56@oss.qualcomm.com Signed-off-by: Dmitry Baryshkov Signed-off-by: Sasha Levin --- Based on my analysis, here is my determination: **YES** This commit should be backported to stable kernel trees for the following reasons: 1. **It fixes a missing dependency issue**: The commit addresses a real dependency problem where `DRM_AUX_BRIDGE` uses `devm_drm_of_get_bridge()` which is implemented in `bridge/panel.c`. As shown in the Makefile analysis, `panel.o` is built into `drm_kms_helper.o` when `CONFIG_DRM_PANEL_BRIDGE` is selected (line 149 of drivers/gpu/drm/Makefile: `drm_kms_helper-$(CONFIG_DRM_PANEL_BRIDGE) += bridge/panel.o`). 2. **It prevents build failures**: Without selecting `DRM_KMS_HELPER`, the aux bridge can fail to link properly because the actual implementation of `devm_drm_of_get_bridge()` won't be available. This can lead to undefined reference errors during linking, similar to the issue described in Similar Commit #1 where `devm_drm_of_get_bridge` was undefined. 3. **The fix is minimal and safe**: The change is a simple one-line addition to select `DRM_KMS_HELPER` in the Kconfig. This is a build configuration fix with no runtime impact - it merely ensures the correct dependencies are satisfied at build time. 4. **It follows established patterns**: Looking at other bridge drivers in the same Kconfig file, we can see that drivers using similar functionality already select `DRM_KMS_HELPER` (e.g., lines 38, 53, 64, 88, 99 in the Kconfig show other drivers selecting it). 5. **Similar to backported commit #2**: This fix is conceptually similar to Similar Commit #2 which was backported and dealt with circular dependencies and proper module organization for `devm_drm_of_get_bridge()`. 6. **No architectural changes**: This commit doesn't introduce new features or change any architecture - it simply fixes a missing Kconfig dependency that should have been there from the beginning when `DRM_AUX_BRIDGE` was introduced. The commit meets the stable tree criteria as it: - Fixes a real bug (missing dependency leading to potential build failures) - Is minimal and contained (single line Kconfig change) - Has no risk of regression (only affects build configuration) - Doesn't introduce new features or architectural changes drivers/gpu/drm/bridge/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig index 09a1be234f717..b9e0ca85226a6 100644 --- a/drivers/gpu/drm/bridge/Kconfig +++ b/drivers/gpu/drm/bridge/Kconfig @@ -16,6 +16,7 @@ config DRM_AUX_BRIDGE tristate depends on DRM_BRIDGE && OF select AUXILIARY_BUS + select DRM_KMS_HELPER select DRM_PANEL_BRIDGE help Simple transparent bridge that is used by several non-DRM drivers to -- 2.39.5