linux.git/drivers/gpu/drm/msm/msm_fbdev.c, branch v7.3-rc2

drm/msm: fbdev: Use a DRM client buffer

2026-07-31T13:50:05+00:00

Replace the internal DRM framebuffer with a DRM client buffer. The
client buffer allocates the DRM framebuffer on a file and also uses
GEM object handles via the regular ADDFB2 interfaces.

Using client-buffer interfaces unifies framebuffer allocation for
DRM clients in user space and msm's internal fbdev emulation. It
also simplifies the clean-up side of the fbdev emulation.

Signed-off-by: Thomas Zimmermann 
Reviewed-by: Dmitry Baryshkov 
Patchwork: https://patchwork.freedesktop.org/patch/733891/
Link: https://lore.kernel.org/r/20260618141249.151338-6-tzimmermann@suse.de
[DB: fixed error handling in msm_fbdev_driver_fbdev_probe]
Signed-off-by: Dmitry Baryshkov

drm/msm: fbdev: Calculate buffer geometry with format helpers

2026-07-31T13:50:01+00:00

Replace the geometry and size calculation in msm's fbdev emulation
with DRM format helpers. This consists of a 4CC lookup from the fbdev
parameters, format lookup, pitch calculation and size calculation.
Then allocate the GEM buffer object for the framebuffer memory from
the calculated size.

Explicitly align the size of the allocated GEM buffer object to full
pages. The contained memory is the framebuffer memory as seen by fbdev.
The page alignment is required for mmap.

v2:
- clarify the page alignment of the buffer size (Dmitry)

Signed-off-by: Thomas Zimmermann 
Reviewed-by: Dmitry Baryshkov 
Patchwork: https://patchwork.freedesktop.org/patch/733885/
Link: https://lore.kernel.org/r/20260618141249.151338-5-tzimmermann@suse.de
Signed-off-by: Dmitry Baryshkov

drm/msm: fbdev: Fix error reporting

2026-07-31T13:48:25+00:00

Replace deprecated error reporting in msm_fbdev_driver_fbdev_probe().
Use drm_warn() and drm_err() instead.

Signed-off-by: Thomas Zimmermann 
Reviewed-by: Dmitry Baryshkov 
Patchwork: https://patchwork.freedesktop.org/patch/733887/
Link: https://lore.kernel.org/r/20260618141249.151338-4-tzimmermann@suse.de
Signed-off-by: Dmitry Baryshkov

drm/msm: fbdev: Inline msm_alloc_stolen_fb()

2026-07-31T13:48:21+00:00

Inline msm_alloc_stolen_fb() into its only caller. This is necessary
for converting fbdev emulation to use client buffers.

There are some minor changes:

- Handle errors for the non-stolen BO in the respective branch.

- Fill mode_cmd right before using it with msm_framebuffer_init(). Both
will later be replaced with client-buffer interfaces.

- Set the modifier[0] to DRM_FORMAT_MOD_LINEAR. No functional change.

- Integrate the error handling with the existing clean-up.

Signed-off-by: Thomas Zimmermann 
Reviewed-by: Dmitry Baryshkov 
Patchwork: https://patchwork.freedesktop.org/patch/733884/
Link: https://lore.kernel.org/r/20260618141249.151338-3-tzimmermann@suse.de
Signed-off-by: Dmitry Baryshkov

drm/fb-helper: Allocate and release fb_info in single place

2025-11-25T10:02:43+00:00

Move the calls to drm_fb_helper_alloc_info() from drivers into a
single place in fbdev helpers. Allocates struct fb_info for a new
framebuffer device. Then call drm_fb_helper_single_fb_probe() to
create an fbdev screen buffer. Also release the instance on errors
by calling drm_fb_helper_release_info().

Simplifies the code and fixes the error cleanup for some of the
drivers.

Regular release of the struct fb_info instance still happens in
drm_fb_helper_fini() as before.

v2:
- remove error rollback in driver implementations (kernel test robot)
- initialize info in TTM implementation (kernel test robot)

Signed-off-by: Thomas Zimmermann 
Acked-by: Christian König  # radeon
Acked-by: Dmitry Baryshkov  # msm
Acked-by: Javier Martinez Canillas 
Link: https://patch.msgid.link/20251027081245.80262-1-tzimmermann@suse.de

drm/client: Add client free callback to unprepare fb_helper

2025-10-24T06:44:10+00:00

Add free callback to struct drm_client_funcs. Invoke function to
free the client memory as part of the release process. Implement
free for fbdev emulation.

Fbdev emulation allocates and prepares client memory in
drm_fbdev_client_setup(). The release happens in fb_destroy from
struct fb_ops. Multiple implementations of this callback exist in
the various drivers that provide an fbdev implementation. Each of
them needs to follow the implementation details of the fbdev setup
code.

Adding a free callback for the client puts the unprepare and release
of the fbdev client in a single place.

Signed-off-by: Thomas Zimmermann 
Reviewed-by: Dmitry Baryshkov  # core, msm
Acked-by: Tomi Valkeinen  # omapdrm
Acked-by: Patrik Jakobsson  # gma500
Acked-by: Alex Deucher 
Link: https://lore.kernel.org/r/20251009132006.45834-2-tzimmermann@suse.de

drm/msm: Rename msm_gem_address_space -> msm_gem_vm

2025-07-04T18:09:44+00:00

Re-aligning naming to better match drm_gpuvm terminology will make
things less confusing at the end of the drm_gpuvm conversion.

This is just rename churn, no functional change.

Signed-off-by: Rob Clark 
Reviewed-by: Dmitry Baryshkov 
Signed-off-by: Rob Clark 
Tested-by: Antonino Maniscalco 
Reviewed-by: Antonino Maniscalco 
Patchwork: https://patchwork.freedesktop.org/patch/661466/

drm/msm: Run DRM default client setup

2024-09-26T07:31:29+00:00

Rework fbdev probing to support fbdev_probe in struct drm_driver
and remove the old fb_probe callback. Provide an initializer macro
for struct drm_driver that sets the callback according to the kernel
configuration.

Call drm_client_setup() to run the kernel's default client setup
for DRM. Set fbdev_probe in struct drm_driver, so that the client
setup can start the common fbdev client.

The msm driver specifies a preferred color mode of 32. As this
is the default if no format has been given, leave it out entirely.

v5:
- select DRM_CLIENT_SELECTION

Signed-off-by: Thomas Zimmermann 
Cc: Rob Clark 
Cc: Abhinav Kumar 
Cc: Dmitry Baryshkov 
Cc: Sean Paul 
Cc: Marijn Suijten 
Acked-by: Javier Martinez Canillas 
Reviewed-by: Dmitry Baryshkov 
Link: https://patchwork.freedesktop.org/patch/msgid/20240924071734.98201-77-tzimmermann@suse.de

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/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