linux.git/drivers/gpu/drm/drm_fbdev_generic.c, branch v6.6.132

drm/fbdev-generic: Do not set physical framebuffer address

2024-06-16T11:47:37+00:00

commit 87cb4a612a89690b123e68f6602d9f6581b03597 upstream.

Framebuffer memory is allocated via vzalloc() from non-contiguous
physical pages. The physical framebuffer start address is therefore
meaningless. Do not set it.

The value is not used within the kernel and only exported to userspace
on dedicated ARM configs. No functional change is expected.

v2:
- refer to vzalloc() in commit message (Javier)

Signed-off-by: Thomas Zimmermann 
Fixes: a5b44c4adb16 ("drm/fbdev-generic: Always use shadow buffering")
Cc: Thomas Zimmermann 
Cc: Javier Martinez Canillas 
Cc: Zack Rusin 
Cc: Maarten Lankhorst 
Cc: Maxime Ripard 
Cc:  # v6.4+
Reviewed-by: Javier Martinez Canillas 
Reviewed-by: Zack Rusin 
Reviewed-by: Sui Jingfeng 
Tested-by: Sui Jingfeng 
Acked-by: Maxime Ripard 
Link: https://patchwork.freedesktop.org/patch/msgid/20240419083331.7761-2-tzimmermann@suse.de
(cherry picked from commit 73ef0aecba78aa9ebd309b10b6cd17d94e632892)
Signed-off-by: Maarten Lankhorst 
Signed-off-by: Greg Kroah-Hartman

fbdev: Align deferred I/O with naming of helpers

2023-07-31T18:07:24+00:00

Deferred-I/O generator macros generate callbacks for struct fb_ops
that operate on memory ranges in I/O address space or system address
space. Rename the macros to use the _IOMEM_ and _SYSMEM_ infixes of
their underlying helpers. Adapt all users. No functional changes.

Signed-off-by: Thomas Zimmermann 
Reviewed-by: Sam Ravnborg 
Acked-by: Helge Deller 
Link: https://patchwork.freedesktop.org/patch/msgid/20230729193157.15446-5-tzimmermann@suse.de

drm: Remove flag FBINFO_DEFAULT from fbdev emulation

2023-07-24T14:50:38+00:00

The flag FBINFO_DEFAULT is 0 and has no effect, as struct fbinfo.flags
has been allocated to zero by framebuffer_alloc(). So do not set it.

Flags should signal differences from the default values. After cleaning
up all occurrences of FBINFO_DEFAULT, the token will be removed.

v2:
	* fix commit message (Miguel)

Signed-off-by: Thomas Zimmermann 
Acked-by: Sam Ravnborg 
Cc: Patrik Jakobsson 
Cc: Alex Deucher 
Cc: "Christian König" 
Cc: "Pan, Xinhui" 
Link: https://patchwork.freedesktop.org/patch/msgid/20230715185343.7193-2-tzimmermann@suse.de

drm/client: Send hotplug event after registering a client

2023-07-11T12:02:01+00:00

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 6e3f17ee73f7 ("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 0e3172bac3f4 ("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 
Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/2649
Fixes: 6e3f17ee73f7 ("drm/fb-helper: generic: Call drm_client_add() after setup is done")
Fixes: 8ab59da26bc0 ("drm/fb-helper: Move generic fbdev emulation into separate source file")
Fixes: b79fe9abd58b ("drm/fbdev-dma: Implement fbdev emulation for GEM DMA helpers")
Fixes: 63c381552f69 ("drm/armada: Implement fbdev emulation as in-kernel client")
Fixes: 49953b70e7d3 ("drm/exynos: Implement fbdev emulation as in-kernel client")
Fixes: 8f1aaccb04b7 ("drm/gma500: Implement client-based fbdev emulation")
Fixes: 940b869c2f2f ("drm/msm: Implement fbdev emulation as in-kernel client")
Fixes: 9e69bcd88e45 ("drm/omapdrm: Implement fbdev emulation as in-kernel client")
Fixes: e317a69fe891 ("drm/radeon: Implement client-based fbdev emulation")
Fixes: 71ec16f45ef8 ("drm/tegra: Implement fbdev emulation as in-kernel client")
Fixes: 0e3172bac3f4 ("drm/amdgpu: Don't set struct drm_driver.output_poll_changed")
Signed-off-by: Thomas Zimmermann 
Tested-by: Moritz Duge 
Tested-by: Torsten Krah 
Tested-by: Paul Schyska 
Cc: Daniel Vetter 
Cc: David Airlie 
Cc: Noralf Trønnes 
Cc: Maarten Lankhorst 
Cc: Maxime Ripard 
Cc: Javier Martinez Canillas 
Cc: Russell King 
Cc: Inki Dae 
Cc: Seung-Woo Kim 
Cc: Kyungmin Park 
Cc: Krzysztof Kozlowski 
Cc: Patrik Jakobsson 
Cc: Rob Clark 
Cc: Abhinav Kumar 
Cc: Dmitry Baryshkov 
Cc: Tomi Valkeinen 
Cc: Alex Deucher 
Cc: "Christian König" 
Cc: "Pan, Xinhui" 
Cc: Thierry Reding 
Cc: Mikko Perttunen 
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:  # v5.2+
Reviewed-by: Javier Martinez Canillas 
Reviewed-by: Dmitry Baryshkov  # msm
Link: https://patchwork.freedesktop.org/patch/msgid/20230710091029.27503-1-tzimmermann@suse.de

drm/fbdev-generic: Implement dedicated fbdev I/O helpers

2023-06-01T10:41:40+00:00

Implement dedicated fbdev helpers for framebuffer I/O instead
of using DRM's helpers. Use an fbdev generator macro for
deferred I/O to create the callbacks. Fbdev-generic was the
only caller of the DRM helpers, so remove them from the helper
module.

v4:
	* generate deferred-I/O helpers
	* use initializer macros for fb_ops
v2:
	* use FB_SYS_HELPERS_DEFERRED option

Signed-off-by: Thomas Zimmermann 
Tested-by: Sui Jingfeng 
Reviewed-by: Sui Jingfeng 
Link: https://patchwork.freedesktop.org/patch/msgid/20230530151228.22979-13-tzimmermann@suse.de

drm/fbdev-generic: Rename symbols

2023-03-22T12:32:54+00:00

Rename symbols to match the style of other fbdev-emulation source
code. No functional changes.

Signed-off-by: Thomas Zimmermann 
Reviewed-by: Javier Martinez Canillas 
Acked-by: Zack Rusin 
Tested-by: Sui Jingfeng 
Link: https://patchwork.freedesktop.org/patch/msgid/20230320150751.20399-9-tzimmermann@suse.de

drm/fbdev-generic: Clean up after failed probing

2023-03-22T12:32:52+00:00

Clean up fbdev and client state if the probe function fails. It
used to leak allocated resources. Also reorder the individual steps
to simplify cleanup.

v2:
	* move screen_size update into separate patches

Signed-off-by: Thomas Zimmermann 
Reviewed-by: Javier Martinez Canillas 
Acked-by: Zack Rusin 
Tested-by: Sui Jingfeng 
Link: https://patchwork.freedesktop.org/patch/msgid/20230320150751.20399-7-tzimmermann@suse.de

drm/fbdev-generic: Set screen size to size of GEM buffer

2023-03-22T12:32:51+00:00

The size of the screen memory should be equivalent to the size of
the screen's GEM buffer. Don't recalculate the value.

Signed-off-by: Thomas Zimmermann 
Reviewed-by: Javier Martinez Canillas 
Tested-by: Sui Jingfeng 
Link: https://patchwork.freedesktop.org/patch/msgid/20230320150751.20399-6-tzimmermann@suse.de

drm/fbdev-generic: Always use shadow buffering

2023-03-22T12:32:46+00:00

Remove all codepaths that implement fbdev output directly on GEM
buffers. Always allocate a shadow buffer in system memory and set
up deferred I/O for mmap.

The fbdev code that operated directly on GEM buffers was used by
drivers based on GEM DMA helpers. Those drivers have been migrated
to use fbdev-dma, a dedicated fbdev emulation for DMA memory. All
remaining users of fbdev-generic require shadow buffering.

Memory management of the remaining callers uses TTM, GEM SHMEM
helpers or a variant of GEM DMA helpers that is incompatible with
fbdev-dma. Therefore remove the unused codepaths from fbdev-generic
and simplify the code.

Using a shadow buffer with deferred I/O is probably the best case
for most remaining callers. Some of the TTM-based drivers might
benefit from a dedicated fbdev emulation that operates directly on
the driver's video memory.

Signed-off-by: Thomas Zimmermann 
Reviewed-by: Javier Martinez Canillas 
Acked-by: Zack Rusin 
Tested-by: Sui Jingfeng 
Link: https://patchwork.freedesktop.org/patch/msgid/20230320150751.20399-2-tzimmermann@suse.de

drm/fb-helper: Remove drm_fb_helper_unprepare() from drm_fb_helper_fini()

2023-02-21T12:26:18+00:00

Move drm_fb_helper_unprepare() from drm_fb_helper_fini() into the
calling fbdev implementation. Avoids a possible stale mutex with
generic fbdev code.

As indicated by its name, drm_fb_helper_prepare() prepares struct
drm_fb_helper before setting up the fbdev support with a call to
drm_fb_helper_init(). In legacy fbdev emulation, this happens next
to each other. If successful, drm_fb_helper_fini() later tear down
the fbdev device and also unprepare via drm_fb_helper_unprepare().

Generic fbdev emulation prepares struct drm_fb_helper immediately
after allocating the instance. It only calls drm_fb_helper_init()
as part of processing a hotplug event. If the hotplug-handling fails,
it runs drm_fb_helper_fini(). This unprepares the fb-helper instance
and the next hotplug event runs on stale data.

Solve this by moving drm_fb_helper_unprepare() from drm_fb_helper_fini()
into the fbdev implementations. Call it right before freeing the
fb-helper instance.

Fixes: 643231b28380 ("drm/fbdev-generic: Minimize hotplug error handling")
Cc: Thomas Zimmermann 
Cc: Javier Martinez Canillas 
Cc: Maarten Lankhorst 
Cc: Maxime Ripard 
Cc: David Airlie 
Cc: Daniel Vetter 
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Thomas Zimmermann 
Reviewed-by: Daniel Vetter 
Reviewed-by: Javier Martinez Canillas 
Link: https://patchwork.freedesktop.org/patch/msgid/20230216140620.17699-1-tzimmermann@suse.de