drm/fbdev-dma: Add shadow buffering for deferred I/O

DMA areas are not necessarily backed by struct page, so we cannot
rely on it for deferred I/O. Allocate a shadow buffer for drivers
that require

drm/fbdev-dma: Add shadow buffering for deferred I/O

DMA areas are not necessarily backed by struct page, so we cannot
rely on it for deferred I/O. Allocate a shadow buffer for drivers
that require deferred I/O and use it as framebuffer memory.

Fixes driver errors about being "Unable to handle kernel NULL pointer
dereference at virtual address" or "Unable to handle kernel paging
request at virtual address".

The patch splits drm_fbdev_dma_driver_fbdev_probe() in an initial
allocation, which creates the DMA-backed buffer object, and a tail
that sets up the fbdev data structures. There is a tail function for
direct memory mappings and a tail function for deferred I/O with
the shadow buffer.

It is no longer possible to use deferred I/O without shadow buffer.
It can be re-added if there exists a reliably test for usable struct
page in the allocated DMA-backed buffer object.

Signed-off-by: Thomas Zimmermann <[email protected]>
Reported-by: Nuno Gonçalves <[email protected]>
CLoses: https://lore.kernel.org/dri-devel/CAEXMXLR55DziAMbv_+2hmLeH-jP96pmit6nhs6siB22cpQFr9w@mail.gmail.com/
Tested-by: Nuno Gonçalves <[email protected]>
Fixes: 5ab91447aa13 ("drm/tiny/ili9225: Use fbdev-dma")
Cc: Thomas Zimmermann <[email protected]>
Cc: <[email protected]> # v6.11+
Reviewed-by: Simona Vetter <[email protected]>
Reviewed-by: Javier Martinez Canillas <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

show more ...

drm/fbdev-dma: Only cleanup deferred I/O if necessary

Commit 5a498d4d06d6 ("drm/fbdev-dma: Only install deferred I/O if
necessary") initializes deferred I/O only if it is used.
drm_fbdev_dma_fb_dest

drm/fbdev-dma: Only cleanup deferred I/O if necessary

Commit 5a498d4d06d6 ("drm/fbdev-dma: Only install deferred I/O if
necessary") initializes deferred I/O only if it is used.
drm_fbdev_dma_fb_destroy() however calls fb_deferred_io_cleanup()
unconditionally with struct fb_info.fbdefio == NULL. KASAN with the
out-of-tree Apple silicon display driver posts following warning from
__flush_work() of a random struct work_struct instead of the expected
NULL pointer derefs.

[ 22.053799] ------------[ cut here ]------------
[ 22.054832] WARNING: CPU: 2 PID: 1 at kernel/workqueue.c:4177 __flush_work+0x4d8/0x580
[ 22.056597] Modules linked in: uhid bnep uinput nls_ascii ip6_tables ip_tables i2c_dev loop fuse dm_multipath nfnetlink zram hid_magicmouse btrfs xor xor_neon brcmfmac_wcc raid6_pq hci_bcm4377 bluetooth brcmfmac hid_apple brcmutil nvmem_spmi_mfd simple_mfd_spmi dockchannel_hid cfg80211 joydev regmap_spmi nvme_apple ecdh_generic ecc macsmc_hid rfkill dwc3 appledrm snd_soc_macaudio macsmc_power nvme_core apple_isp phy_apple_atc apple_sart apple_rtkit_helper apple_dockchannel tps6598x macsmc_hwmon snd_soc_cs42l84 videobuf2_v4l2 spmi_apple_controller nvmem_apple_efuses videobuf2_dma_sg apple_z2 videobuf2_memops spi_nor panel_summit videobuf2_common asahi videodev pwm_apple apple_dcp snd_soc_apple_mca apple_admac spi_apple clk_apple_nco i2c_pasemi_platform snd_pcm_dmaengine mc i2c_pasemi_core mux_core ofpart adpdrm drm_dma_helper apple_dart apple_soc_cpufreq leds_pwm phram
[ 22.073768] CPU: 2 UID: 0 PID: 1 Comm: systemd-shutdow Not tainted 6.11.2-asahi+ #asahi-dev
[ 22.075612] Hardware name: Apple MacBook Pro (13-inch, M2, 2022) (DT)
[ 22.077032] pstate: 01400005 (nzcv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
[ 22.078567] pc : __flush_work+0x4d8/0x580
[ 22.079471] lr : __flush_work+0x54/0x580
[ 22.080345] sp : ffffc000836ef820
[ 22.081089] x29: ffffc000836ef880 x28: 0000000000000000 x27: ffff80002ddb7128
[ 22.082678] x26: dfffc00000000000 x25: 1ffff000096f0c57 x24: ffffc00082d3e358
[ 22.084263] x23: ffff80004b7862b8 x22: dfffc00000000000 x21: ffff80005aa1d470
[ 22.085855] x20: ffff80004b786000 x19: ffff80004b7862a0 x18: 0000000000000000
[ 22.087439] x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000005
[ 22.089030] x14: 1ffff800106ddf0a x13: 0000000000000000 x12: 0000000000000000
[ 22.090618] x11: ffffb800106ddf0f x10: dfffc00000000000 x9 : 1ffff800106ddf0e
[ 22.092206] x8 : 0000000000000000 x7 : aaaaaaaaaaaaaaaa x6 : 0000000000000001
[ 22.093790] x5 : ffffc000836ef728 x4 : 0000000000000000 x3 : 0000000000000020
[ 22.095368] x2 : 0000000000000008 x1 : 00000000000000aa x0 : 0000000000000000
[ 22.096955] Call trace:
[ 22.097505] __flush_work+0x4d8/0x580
[ 22.098330] flush_delayed_work+0x80/0xb8
[ 22.099231] fb_deferred_io_cleanup+0x3c/0x130
[ 22.100217] drm_fbdev_dma_fb_destroy+0x6c/0xe0 [drm_dma_helper]
[ 22.101559] unregister_framebuffer+0x210/0x2f0
[ 22.102575] drm_fb_helper_unregister_info+0x48/0x60
[ 22.103683] drm_fbdev_dma_client_unregister+0x4c/0x80 [drm_dma_helper]
[ 22.105147] drm_client_dev_unregister+0x1cc/0x230
[ 22.106217] drm_dev_unregister+0x58/0x570
[ 22.107125] apple_drm_unbind+0x50/0x98 [appledrm]
[ 22.108199] component_del+0x1f8/0x3a8
[ 22.109042] dcp_platform_shutdown+0x24/0x38 [apple_dcp]
[ 22.110357] platform_shutdown+0x70/0x90
[ 22.111219] device_shutdown+0x368/0x4d8
[ 22.112095] kernel_restart+0x6c/0x1d0
[ 22.112946] __arm64_sys_reboot+0x1c8/0x328
[ 22.113868] invoke_syscall+0x78/0x1a8
[ 22.114703] do_el0_svc+0x124/0x1a0
[ 22.115498] el0_svc+0x3c/0xe0
[ 22.116181] el0t_64_sync_handler+0x70/0xc0
[ 22.117110] el0t_64_sync+0x190/0x198
[ 22.117931] ---[ end trace 0000000000000000 ]---

Signed-off-by: Janne Grunau <[email protected]>
Fixes: 5a498d4d06d6 ("drm/fbdev-dma: Only install deferred I/O if necessary")
Reviewed-by: Thomas Zimmermann <[email protected]>
Reviewed-by: Linus Walleij <[email protected]>
Signed-off-by: Thomas Zimmermann <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/ZwLNuZL-8Gh5UUQb@robin

show more ...

drm/fbdev-dma: Remove obsolete setup function

The old setup function drm_fbdev_dma_setup() is unused. Remove it and
its internal callbacks. New drivers should call drm_client_setup()
instead.

Signe

drm/fbdev-dma: Remove obsolete setup function

The old setup function drm_fbdev_dma_setup() is unused. Remove it and
its internal callbacks. New drivers should call drm_client_setup()
instead.

Signed-off-by: Thomas Zimmermann <[email protected]>
Reviewed-by: Javier Martinez Canillas <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

show more ...

drm/fbdev-dma: Support struct drm_driver.fbdev_probe

Rework fbdev probing to support fbdev_probe in struct drm_driver
and reimplement the old fb_probe callback on top of it. Provide an
initializer m

drm/fbdev-dma: Support struct drm_driver.fbdev_probe

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

This change allows the common fbdev client to run on top of DMA-
based DRM drivers.

Signed-off-by: Thomas Zimmermann <[email protected]>
Reviewed-by: Javier Martinez Canillas <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

show more ...

drm/fbdev-dma: Only install deferred I/O if necessary

Deferred I/O requires struct page for framebuffer memory, which is
not guaranteed for all DMA ranges. We thus only install deferred I/O
if we ha

drm/fbdev-dma: Only install deferred I/O if necessary

Deferred I/O requires struct page for framebuffer memory, which is
not guaranteed for all DMA ranges. We thus only install deferred I/O
if we have a framebuffer that requires it.

A reported bug affected the ipu-v3 and pl111 drivers, which have video
memory in either Normal or HighMem zones

[ 0.000000] Zone ranges:
[ 0.000000] Normal [mem 0x0000000010000000-0x000000003fffffff]
[ 0.000000] HighMem [mem 0x0000000040000000-0x000000004fffffff]

where deferred I/O only works correctly with HighMem. See the Closes
tags for bug reports.

v2:
- test if screen_buffer supports deferred I/O (Sima)

Signed-off-by: Thomas Zimmermann <[email protected]>
Fixes: 808a40b69468 ("drm/fbdev-dma: Implement damage handling and deferred I/O")
Reported-by: Alexander Stein <[email protected]>
Closes: https://lore.kernel.org/all/23636953.6Emhk5qWAg@steina-w/
Reported-by: Linus Walleij <[email protected]>
Closes: https://lore.kernel.org/dri-devel/CACRpkdb+hb9AGavbWpY-=uQQ0apY9en_tWJioPKf_fAbXMP4Hg@mail.gmail.com/
Tested-by: Alexander Stein <[email protected]>
Tested-by: Linus Walleij <[email protected]>
Cc: Thomas Zimmermann <[email protected]>
Cc: Javier Martinez Canillas <[email protected]>
Cc: Maarten Lankhorst <[email protected]>
Cc: Maxime Ripard <[email protected]>
Reviewed-by: Simona Vetter <[email protected]>
Reviewed-by: Linus Walleij <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

show more ...

drm/fbdev-dma: Fix framebuffer mode for big endian devices

The drm_mode_legacy_fb_format() function only generates formats suitable
for little endian devices. switch to drm_driver_legacy_fb_format()

drm/fbdev-dma: Fix framebuffer mode for big endian devices

The drm_mode_legacy_fb_format() function only generates formats suitable
for little endian devices. switch to drm_driver_legacy_fb_format() here
instead to take the device endianness into consideration, too.

Suggested-by: Thomas Zimmermann <[email protected]>
Signed-off-by: Thomas Huth <[email protected]>
Reviewed-by: Thomas Zimmermann <[email protected]>
Reviewed-by: Javier Martinez Canillas <[email protected]>
Signed-off-by: Thomas Zimmermann <[email protected]>
Fixes: 6ae2ff23aa43 ("drm/client: Convert drm_client_buffer_addfb() to drm_mode_addfb2()")
Cc: Geert Uytterhoeven <[email protected]>
Cc: Javier Martinez Canillas <[email protected]>
Cc: Hamza Mahfooz <[email protected]>
Cc: Maarten Lankhorst <[email protected]>
Cc: Maxime Ripard <[email protected]>
Cc: Thomas Zimmermann <[email protected]>
Cc: <[email protected]> # v6.7+
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

show more ...

drm/fbdev-dma: Only set smem_start is enable per module option

Only export struct fb_info.fix.smem_start if that is required by the
user and the memory does not come from vmalloc().

Setting struct

drm/fbdev-dma: Only set smem_start is enable per module option

Only export struct fb_info.fix.smem_start if that is required by the
user and the memory does not come from vmalloc().

Setting struct fb_info.fix.smem_start breaks systems where DMA
memory is backed by vmalloc address space. An example error is
shown below.

[ 3.536043] ------------[ cut here ]------------
[ 3.540716] virt_to_phys used for non-linear address: 000000007fc4f540 (0xffff800086001000)
[ 3.552628] WARNING: CPU: 4 PID: 61 at arch/arm64/mm/physaddr.c:12 __virt_to_phys+0x68/0x98
[ 3.565455] Modules linked in:
[ 3.568525] CPU: 4 PID: 61 Comm: kworker/u12:5 Not tainted 6.6.23-06226-g4986cc3e1b75-dirty #250
[ 3.577310] Hardware name: NXP i.MX95 19X19 board (DT)
[ 3.582452] Workqueue: events_unbound deferred_probe_work_func
[ 3.588291] pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[ 3.595233] pc : __virt_to_phys+0x68/0x98
[ 3.599246] lr : __virt_to_phys+0x68/0x98
[ 3.603276] sp : ffff800083603990
[ 3.677939] Call trace:
[ 3.680393] __virt_to_phys+0x68/0x98
[ 3.684067] drm_fbdev_dma_helper_fb_probe+0x138/0x238
[ 3.689214] __drm_fb_helper_initial_config_and_unlock+0x2b0/0x4c0
[ 3.695385] drm_fb_helper_initial_config+0x4c/0x68
[ 3.700264] drm_fbdev_dma_client_hotplug+0x8c/0xe0
[ 3.705161] drm_client_register+0x60/0xb0
[ 3.709269] drm_fbdev_dma_setup+0x94/0x148

Additionally, DMA memory is assumed to by contiguous in physical
address space, which is not guaranteed by vmalloc().

Resolve this by checking the module flag drm_leak_fbdev_smem when
DRM allocated the instance of struct fb_info. Fbdev-dma then only
sets smem_start only if required (via FBINFO_HIDE_SMEM_START). Also
guarantee that the framebuffer is not located in vmalloc address
space.

Signed-off-by: Thomas Zimmermann <[email protected]>
Reported-by: Peng Fan (OSS) <[email protected]>
Closes: https://lore.kernel.org/dri-devel/[email protected]/
Reported-by: Geert Uytterhoeven <[email protected]>
Closes: https://lore.kernel.org/dri-devel/CAMuHMdX3N0szUvt1VTbroa2zrT1Nye_VzPb5qqCZ7z5gSm7HGw@mail.gmail.com/
Fixes: a51c7663f144 ("drm/fb-helper: Consolidate CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM")
Tested-by: Geert Uytterhoeven <[email protected]>
Reviewed-by: Daniel Vetter <[email protected]>
Cc: <[email protected]> # v6.4+
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

show more ...

drm/fbdev-dma: Clean up deferred I/O

Call fb_deferred_io_cleanup() upon destroying the framebuffer
device. Releases the internal memory.

Signed-off-by: Thomas Zimmermann <[email protected]>
Fixes

drm/fbdev-dma: Clean up deferred I/O

Call fb_deferred_io_cleanup() upon destroying the framebuffer
device. Releases the internal memory.

Signed-off-by: Thomas Zimmermann <[email protected]>
Fixes: 808a40b69468 ("drm/fbdev-dma: Implement damage handling and deferred I/O")
Cc: Thomas Zimmermann <[email protected]>
Cc: Javier Martinez Canillas <[email protected]>
Cc: Maarten Lankhorst <[email protected]>
Cc: Maxime Ripard <[email protected]>
Reviewed-by: Javier Martinez Canillas <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

show more ...

drm/fbdev-dma: Implement damage handling and deferred I/O

Add support for damage handling and deferred I/O to fbdev-dma. This
enables fbdev-dma to support all DMA-memory-based DRM drivers, even
such

drm/fbdev-dma: Implement damage handling and deferred I/O

Add support for damage handling and deferred I/O to fbdev-dma. This
enables fbdev-dma to support all DMA-memory-based DRM drivers, even
such with a dirty callback in their framebuffers.

The patch adds the code for deferred I/O and also sets a dedicated
helper for struct fb_ops.fb_mmap that support coherent mappings.

v3:
- init fb_ops with FB_GEN_DEFAULT_DEFERRED_DMAMEM_OPS() (Javier)

Signed-off-by: Thomas Zimmermann <[email protected]>
Reviewed-by: Javier Martinez Canillas <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

show more ...

fbdev: Use _DMAMEM_ infix for DMA-memory helpers

Change the infix for fbdev's DMA-memory helpers from _DMA_ to
_DMAMEM_. The helpers perform operations within DMA-able memory,
but they don't perform

fbdev: Use _DMAMEM_ infix for DMA-memory helpers

Change the infix for fbdev's DMA-memory helpers from _DMA_ to
_DMAMEM_. The helpers perform operations within DMA-able memory,
but they don't perform DMA operations. Naming should make this
clear. Adapt all users. No functional changes.

Signed-off-by: Thomas Zimmermann <[email protected]>
Reviewed-by: Sam Ravnborg <[email protected]>
Acked-by: Helge Deller <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

show more ...

drm/fbdev-dma: Use fbdev DMA helpers

Use fbdev's DMA helpers for fbdev-dma. They are equivalent to the
previously used system-memory helpers, so no functional changes here.

Signed-off-by: Thomas Zi

drm/fbdev-dma: Use fbdev DMA helpers

Use fbdev's DMA helpers for fbdev-dma. They are equivalent to the
previously used system-memory helpers, so no functional changes here.

Signed-off-by: Thomas Zimmermann <[email protected]>
Reviewed-by: Javier Martinez Canillas <[email protected]>
Acked-by: Maxime Ripard <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

show more ...

drm: Remove flag FBINFO_DEFAULT from fbdev emulation

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.

Flag

drm: Remove flag FBINFO_DEFAULT from fbdev emulation

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 <[email protected]>
Acked-by: Sam Ravnborg <[email protected]>
Cc: Patrik Jakobsson <[email protected]>
Cc: Alex Deucher <[email protected]>
Cc: "Christian König" <[email protected]>
Cc: "Pan, Xinhui" <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

show more ...

drm/client: Send hotplug event after registering a client

Generate a hotplug event after registering a client to allow the
client to configure its display. Remove the hotplug calls from the
existing

drm/client: Send hotplug event after registering a client

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 <[email protected]>
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 <[email protected]>
Tested-by: Moritz Duge <[email protected]>
Tested-by: Torsten Krah <[email protected]>
Tested-by: Paul Schyska <[email protected]>
Cc: Daniel Vetter <[email protected]>
Cc: David Airlie <[email protected]>
Cc: Noralf Trønnes <[email protected]>
Cc: Maarten Lankhorst <[email protected]>
Cc: Maxime Ripard <[email protected]>
Cc: Javier Martinez Canillas <[email protected]>
Cc: Russell King <[email protected]>
Cc: Inki Dae <[email protected]>
Cc: Seung-Woo Kim <[email protected]>
Cc: Kyungmin Park <[email protected]>
Cc: Krzysztof Kozlowski <[email protected]>
Cc: Patrik Jakobsson <[email protected]>
Cc: Rob Clark <[email protected]>
Cc: Abhinav Kumar <[email protected]>
Cc: Dmitry Baryshkov <[email protected]>
Cc: Tomi Valkeinen <[email protected]>
Cc: Alex Deucher <[email protected]>
Cc: "Christian König" <[email protected]>
Cc: "Pan, Xinhui" <[email protected]>
Cc: Thierry Reding <[email protected]>
Cc: Mikko Perttunen <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: <[email protected]> # v5.2+
Reviewed-by: Javier Martinez Canillas <[email protected]>
Reviewed-by: Dmitry Baryshkov <[email protected]> # msm
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

show more ...

drm/fbdev-dma: Fix documented default preferred_bpp value

As of commit 6c80a93be62d398e ("drm/fb-helper: Initialize fb-helper's
preferred BPP in prepare function"), the preferred_bpp parameter of
dr

drm/fbdev-dma: Fix documented default preferred_bpp value

As of commit 6c80a93be62d398e ("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: b79fe9abd58bab73 ("drm/fbdev-dma: Implement fbdev emulation for GEM DMA helpers")
Signed-off-by: Geert Uytterhoeven <[email protected]>
Reviewed-by: Thomas Zimmermann <[email protected]>
Signed-off-by: Thomas Zimmermann <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/91f093ffe436a9f94d58fb2bfbc1407f1ebe8bb0.1688656591.git.geert+renesas@glider.be

show more ...

drm: Remove struct drm_driver.gem_prime_mmap

All drivers initialize this field with drm_gem_prime_mmap(). Call
the function directly and remove the field. Simplifies the code and
resolves a long-sta

drm: Remove struct drm_driver.gem_prime_mmap

All drivers initialize this field with drm_gem_prime_mmap(). Call
the function directly and remove the field. Simplifies the code and
resolves a long-standing TODO item.

Signed-off-by: Thomas Zimmermann <[email protected]>
Reviewed-by: Alex Deucher <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

show more ...

drm/fbdev-dma: Use regular fbdev I/O helpers

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 wrapp

drm/fbdev-dma: Use regular fbdev I/O helpers

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 <[email protected]>
Acked-by: Sam Ravnborg <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

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drm/fb-helper: Consolidate CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM

Consolidate all handling of CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM by
making the module parameter optional in drm_fb_helper.c.

Without the config

drm/fb-helper: Consolidate CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM

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 <[email protected]>
Reviewed-by: Javier Martinez Canillas <[email protected]>
Acked-by: Zack Rusin <[email protected]>
Tested-by: Sui Jingfeng<[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

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drm/fbdev-dma: Implement fbdev emulation for GEM DMA helpers

Implement fbdev emulation that is optimized for drivers that use
DMA helpers. The buffers may no tbe moveable, may not require damage
han

drm/fbdev-dma: Implement fbdev emulation for GEM DMA helpers

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 <[email protected]>
Reviewed-by: Javier Martinez Canillas <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

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