Re: [PATCH] drm/bridge: Select DRM_KMS_HELPER for DRM_PANEL_BRIDGE

From: Jani Nikula <jani.nikula@linux.intel.com>
To: Neil Armstrong <neil.armstrong@linaro.org>,
	Andrzej Hajda <andrzej.hajda@intel.com>,
	Robert Foss <rfoss@kernel.org>,
	Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
	Jonas Karlman <jonas@kwiboo.se>,
	Jernej Skrabec <jernej.skrabec@gmail.com>,
	Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
	Maxime Ripard <mripard@kernel.org>,
	Thomas Zimmermann <tzimmermann@suse.de>,
	David Airlie <airlied@gmail.com>, Daniel Vetter <daniel@ffwll.ch>,
	Luca Weiss <luca.weiss@fairphone.com>
Cc: ~postmarketos/upstreaming@lists.sr.ht,
	phone-devel@vger.kernel.org, dri-devel@lists.freedesktop.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] drm/bridge: Select DRM_KMS_HELPER for DRM_PANEL_BRIDGE
Date: Mon, 18 Mar 2024 12:59:29 +0200	[thread overview]
Message-ID: <87ttl3pzzi.fsf@intel.com> (raw)
In-Reply-To: <87wmpzq0bp.fsf@intel.com>

On Mon, 18 Mar 2024, Jani Nikula <jani.nikula@linux.intel.com> wrote:
> On Mon, 18 Mar 2024, Neil Armstrong <neil.armstrong@linaro.org> wrote:
>> Hi,
>>
>> On Thu, 11 Jan 2024 13:38:04 +0100, Luca Weiss wrote:
>>> Since the kconfig symbol of DRM_PANEL_BRIDGE is only adding
>>> bridge/panel.o to drm_kms_helper object, we need to select
>>> DRM_KMS_HELPER to make sure the file is actually getting built.
>>> 
>>> Otherwise with certain defconfigs e.g. devm_drm_of_get_bridge will not
>>> be properly available:
>>> 
>>> [...]
>>
>> Thanks, Applied to https://gitlab.freedesktop.org/drm/misc/kernel.git (drm-misc-fixes)
>>
>> [1/1] drm/bridge: Select DRM_KMS_HELPER for DRM_PANEL_BRIDGE
>>       https://gitlab.freedesktop.org/drm/misc/kernel/-/commit/e3f18b0dd1db242791afbc3bd173026163ce0ccc
>
> With my kernel config, e3f18b0dd1db ("drm/bridge: Select DRM_KMS_HELPER
> for DRM_PANEL_BRIDGE") leads to:
>
> WARNING: unmet direct dependencies detected for DRM_KMS_HELPER
>   Depends on [m]: HAS_IOMEM [=y] && DRM [=m]
>   Selected by [y]:
>   - DRM_PANEL_BRIDGE [=y] && HAS_IOMEM [=y] && DRM_BRIDGE [=y]
>   Selected by [m]:
>   - DRM [=m] && HAS_IOMEM [=y] && (AGP [=y] || AGP [=y]=n) && !EMULATED_CMPXCHG && HAS_DMA [=y] && DRM_FBDEV_EMULATION [=y]
>   - DRM_MIPI_DBI [=m] && HAS_IOMEM [=y] && DRM [=m]
>   - DRM_KUNIT_TEST [=m] && HAS_IOMEM [=y] && DRM [=m] && KUNIT [=y] && MMU [=y]
>   - DRM_RADEON [=m] && HAS_IOMEM [=y] && DRM [=m] && PCI [=y] && MMU [=y] && (AGP [=y] || !AGP [=y])
>   - DRM_AMDGPU [=m] && HAS_IOMEM [=y] && DRM [=m] && PCI [=y] && MMU [=y] && !UML
>   - DRM_NOUVEAU [=m] && HAS_IOMEM [=y] && DRM [=m] && PCI [=y] && MMU [=y]
>   - DRM_I915 [=m] && HAS_IOMEM [=y] && DRM [=m] && X86 [=y] && PCI [=y] && !PREEMPT_RT [=n]
>   - DRM_XE [=m] && HAS_IOMEM [=y] && DRM [=m] && PCI [=y] && MMU [=y] && (m && MODULES [=y] || y && KUNIT [=y]=y) && 64BIT [=y]
>   - DRM_VKMS [=m] && HAS_IOMEM [=y] && DRM [=m] && MMU [=y]
>   - DRM_VMWGFX [=m] && HAS_IOMEM [=y] && DRM [=m] && PCI [=y] && MMU [=y] && (X86 [=y] || ARM64)
>   - DRM_GMA500 [=m] && HAS_IOMEM [=y] && DRM [=m] && PCI [=y] && X86 [=y] && MMU [=y]
>   - DRM_UDL [=m] && HAS_IOMEM [=y] && DRM [=m] && USB [=m] && USB_ARCH_HAS_HCD [=y] && MMU [=y]
>   - DRM_AST [=m] && HAS_IOMEM [=y] && DRM [=m] && PCI [=y] && MMU [=y]
>   - DRM_MGAG200 [=m] && HAS_IOMEM [=y] && DRM [=m] && PCI [=y] && MMU [=y]
>   - DRM_QXL [=m] && HAS_IOMEM [=y] && DRM [=m] && PCI [=y] && MMU [=y]
>   - DRM_VIRTIO_GPU [=m] && HAS_IOMEM [=y] && DRM [=m] && VIRTIO_MENU [=y] && MMU [=y]
>   - DRM_BOCHS [=m] && HAS_IOMEM [=y] && DRM [=m] && PCI [=y] && MMU [=y]
>   - DRM_CIRRUS_QEMU [=m] && HAS_IOMEM [=y] && DRM [=m] && PCI [=y] && MMU [=y]
>   - DRM_GM12U320 [=m] && HAS_IOMEM [=y] && DRM [=m] && USB [=m] && MMU [=y]
>   - DRM_PANEL_MIPI_DBI [=m] && HAS_IOMEM [=y] && DRM [=m] && SPI [=y]
>   - DRM_SIMPLEDRM [=m] && HAS_IOMEM [=y] && DRM [=m] && MMU [=y]
>   - TINYDRM_HX8357D [=m] && HAS_IOMEM [=y] && DRM [=m] && SPI [=y]
>   - TINYDRM_ILI9163 [=m] && HAS_IOMEM [=y] && DRM [=m] && SPI [=y]
>   - TINYDRM_ILI9225 [=m] && HAS_IOMEM [=y] && DRM [=m] && SPI [=y]
>   - TINYDRM_ILI9341 [=m] && HAS_IOMEM [=y] && DRM [=m] && SPI [=y]
>   - TINYDRM_ILI9486 [=m] && HAS_IOMEM [=y] && DRM [=m] && SPI [=y]
>   - TINYDRM_MI0283QT [=m] && HAS_IOMEM [=y] && DRM [=m] && SPI [=y]
>   - TINYDRM_REPAPER [=m] && HAS_IOMEM [=y] && DRM [=m] && SPI [=y]
>   - TINYDRM_ST7586 [=m] && HAS_IOMEM [=y] && DRM [=m] && SPI [=y]
>   - TINYDRM_ST7735R [=m] && HAS_IOMEM [=y] && DRM [=m] && SPI [=y]
>   - DRM_XEN_FRONTEND [=m] && HAS_IOMEM [=y] && XEN [=y] && DRM [=m]
>   - DRM_VBOXVIDEO [=m] && HAS_IOMEM [=y] && DRM [=m] && X86 [=y] && PCI [=y]
>   - DRM_GUD [=m] && HAS_IOMEM [=y] && DRM [=m] && USB [=m] && MMU [=y]
>   - DRM_SSD130X [=m] && HAS_IOMEM [=y] && DRM [=m] && MMU [=y]
>   - DRM_ANALOGIX_ANX78XX [=m] && HAS_IOMEM [=y] && DRM [=m] && DRM_BRIDGE [=y]

Please read Documentation/kbuild/kconfig-language.rst.

Basically boolean DRM_PANEL_BRIDGE selecting tristate DRM_KMS_HELPER
forces it to y while it should remain m.

Please revert.

BR,
Jani.

-- 
Jani Nikula, Intel