Generate a hotplug event after registering a client to allow the
client to configure its display. Remove the hotplug calls from the
existing clients for fbdev emulation. This change fixes a concurrency
bug between registering a client and receiving events from the DRM
core. The bug is present in the fbdev emulation of all drivers.
The fbdev emulation currently generates a hotplug event before
registering the client to the device. For each new output, the DRM
core sends an additional hotplug event to each registered client.
If the DRM core detects first output between sending the artificial
hotplug and registering the device, the output's hotplug event gets
lost. If this is the first output, the fbdev console display remains
dark. This has been observed with amdgpu and fbdev-generic.
Fix this by adding hotplug generation directly to the client's
register helper drm_client_register(). Registering the client and
receiving events are serialized by struct drm_device.clientlist_mutex.
So an output is either configured by the initial hotplug event, or
the client has already been registered.
The bug was originally added in commit 6e3f17ee73 ("drm/fb-helper:
generic: Call drm_client_add() after setup is done"), in which adding
a client and receiving a hotplug event switched order. It was hidden,
as most hardware and drivers have at least on static output configured.
Other drivers didn't use the internal DRM client or still had struct
drm_mode_config_funcs.output_poll_changed set. That callback handled
hotplug events as well. After not setting the callback in amdgpu in
commit 0e3172bac3 ("drm/amdgpu: Don't set struct
drm_driver.output_poll_changed"), amdgpu did not show a framebuffer
console if output events got lost. The bug got copy-pasted from
fbdev-generic into the other fbdev emulation.
Reported-by: Moritz Duge <MoritzDuge@kolahilft.de>
Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/2649
Fixes: 6e3f17ee73 ("drm/fb-helper: generic: Call drm_client_add() after setup is done")
Fixes: 8ab59da26b ("drm/fb-helper: Move generic fbdev emulation into separate source file")
Fixes: b79fe9abd5 ("drm/fbdev-dma: Implement fbdev emulation for GEM DMA helpers")
Fixes: 63c381552f ("drm/armada: Implement fbdev emulation as in-kernel client")
Fixes: 49953b70e7 ("drm/exynos: Implement fbdev emulation as in-kernel client")
Fixes: 8f1aaccb04 ("drm/gma500: Implement client-based fbdev emulation")
Fixes: 940b869c2f ("drm/msm: Implement fbdev emulation as in-kernel client")
Fixes: 9e69bcd88e ("drm/omapdrm: Implement fbdev emulation as in-kernel client")
Fixes: e317a69fe8 ("drm/radeon: Implement client-based fbdev emulation")
Fixes: 71ec16f45e ("drm/tegra: Implement fbdev emulation as in-kernel client")
Fixes: 0e3172bac3 ("drm/amdgpu: Don't set struct drm_driver.output_poll_changed")
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Tested-by: Moritz Duge <MoritzDuge@kolahilft.de>
Tested-by: Torsten Krah <krah.tm@gmail.com>
Tested-by: Paul Schyska <pschyska@gmail.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Airlie <airlied@gmail.com>
Cc: Noralf Trønnes <noralf@tronnes.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Javier Martinez Canillas <javierm@redhat.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Inki Dae <inki.dae@samsung.com>
Cc: Seung-Woo Kim <sw0312.kim@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Cc: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Abhinav Kumar <quic_abhinavk@quicinc.com>
Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Cc: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Mikko Perttunen <mperttunen@nvidia.com>
Cc: dri-devel@lists.freedesktop.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-samsung-soc@vger.kernel.org
Cc: linux-arm-msm@vger.kernel.org
Cc: freedreno@lists.freedesktop.org
Cc: amd-gfx@lists.freedesktop.org
Cc: linux-tegra@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: <stable@vger.kernel.org> # v5.2+
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> # msm
Link: https://patchwork.freedesktop.org/patch/msgid/20230710091029.27503-1-tzimmermann@suse.de
As of commit 6c80a93be6 ("drm/fb-helper: Initialize fb-helper's
preferred BPP in prepare function"), the preferred_bpp parameter of
drm_fb_helper_prepare() defaults to 32 instead of
drm_mode_config.preferred_depth. Hence this also applies to
drm_fbdev_dma_setup(), which just passes its own preferred_bpp
parameter.
Fixes: b79fe9abd5 ("drm/fbdev-dma: Implement fbdev emulation for GEM DMA helpers")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/91f093ffe436a9f94d58fb2bfbc1407f1ebe8bb0.1688656591.git.geert+renesas@glider.be
Use the regular fbdev helpers for framebuffer I/O instead of DRM's
helpers. Fbdev-dma does not use damage handling, so DRM's fbdev helpers
are mere wrappers around the fbdev code.
By using fbdev helpers directly within each DRM fbdev emulation,
we can eventually remove DRM's wrapper functions entirely.
v4:
* use initializer macros for struct fb_ops
v2:
* use FB_SYS_HELPERS option
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230530151228.22979-8-tzimmermann@suse.de
Consolidate all handling of CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM by
making the module parameter optional in drm_fb_helper.c.
Without the config option, modules can set smem_start in struct
fb_info for internal usage, but not export if to userspace. The
address can only be exported by enabling the option and setting
the module parameter. Also update the comment.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Zack Rusin <zackr@vmware.com>
Tested-by: Sui Jingfeng<suijingfeng@loongson.cn>
Link: https://patchwork.freedesktop.org/patch/msgid/20230320150751.20399-8-tzimmermann@suse.de
Implement fbdev emulation that is optimized for drivers that use
DMA helpers. The buffers may no tbe moveable, may not require damage
handling and have to be located in system memory. This allows fbdev
emulation to operate directly on the buffer and mmap it to userspace.
Besides those constraints, the emulation works like in the generic
code. As an internal DRM client provides, it receives hotplug, restore
and unregister events. The DRM client is independent from the fbdev
probing, which runs on the first successful hotplug event.
The emulation is part of the DMA helper module and not build unless
DMA helpers and fbdev emulation has been configured.
Tested with vc4.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230313155138.20584-2-tzimmermann@suse.de
