Fix this kernel test robot warning:
drivers/video/fbdev/core/fbcon.c: In function 'fbcon_init':
drivers/video/fbdev/core/fbcon.c:1028:6: warning: variable 'cap' set but not used [-Wunused-but-set-variable]
The cap variable is only used when CONFIG_FRAMEBUFFER_CONSOLE_LEGACY_ACCELERATION
is enabled. Drop the temporary variable and use info->flags instead.
Fixes: 87ab9f6b74 ("Revert "fbcon: Disable accelerated scrolling")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/YgFB4xqI+As196FR@p100
Add a config option CONFIG_FRAMEBUFFER_CONSOLE_LEGACY_ACCELERATION to
enable bitblt and fillrect hardware acceleration in the framebuffer
console. If disabled, such acceleration will not be used, even if it is
supported by the graphics hardware driver.
If you plan to use DRM as your main graphics output system, you should
disable this option since it will prevent compiling in code which isn't
used later on when DRM takes over.
For all other configurations, e.g. if none of your graphic cards support
DRM (yet), DRM isn't available for your architecture, or you can't be
sure that the graphic card in the target system will support DRM, you
most likely want to enable this option.
In the non-accelerated case (e.g. when DRM is used), the inlined
fb_scrollmode() function is hardcoded to return SCROLL_REDRAW and as such the
compiler is able to optimize much unneccesary code away.
In this v3 patch version I additionally changed the GETVYRES() and GETVXRES()
macros to take a pointer to the fbcon_display struct. This fixes the build when
console rotation is enabled and helps the compiler again to optimize out code.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # v5.10+
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20220202135531.92183-4-deller@gmx.de
This reverts commit 39aead8373.
Revert the first (of 2) commits which disabled scrolling acceleration in
fbcon/fbdev. It introduced a regression for fbdev-supported graphic cards
because of the performance penalty by doing screen scrolling by software
instead of using the existing graphic card 2D hardware acceleration.
Console scrolling acceleration was disabled by dropping code which
checked at runtime the driver hardware capabilities for the
BINFO_HWACCEL_COPYAREA or FBINFO_HWACCEL_FILLRECT flags and if set, it
enabled scrollmode SCROLL_MOVE which uses hardware acceleration to move
screen contents. After dropping those checks scrollmode was hard-wired
to SCROLL_REDRAW instead, which forces all graphic cards to redraw every
character at the new screen position when scrolling.
This change effectively disabled all hardware-based scrolling acceleration for
ALL drivers, because now all kind of 2D hardware acceleration (bitblt,
fillrect) in the drivers isn't used any longer.
The original commit message mentions that only 3 DRM drivers (nouveau, omapdrm
and gma500) used hardware acceleration in the past and thus code for checking
and using scrolling acceleration is obsolete.
This statement is NOT TRUE, because beside the DRM drivers there are around 35
other fbdev drivers which depend on fbdev/fbcon and still provide hardware
acceleration for fbdev/fbcon.
The original commit message also states that syzbot found lots of bugs in fbcon
and thus it's "often the solution to just delete code and remove features".
This is true, and the bugs - which actually affected all users of fbcon,
including DRM - were fixed, or code was dropped like e.g. the support for
software scrollback in vgacon (commit 973c096f6a).
So to further analyze which bugs were found by syzbot, I've looked through all
patches in drivers/video which were tagged with syzbot or syzkaller back to
year 2005. The vast majority fixed the reported issues on a higher level, e.g.
when screen is to be resized, or when font size is to be changed. The few ones
which touched driver code fixed a real driver bug, e.g. by adding a check.
But NONE of those patches touched code of either the SCROLL_MOVE or the
SCROLL_REDRAW case.
That means, there was no real reason why SCROLL_MOVE had to be ripped-out and
just SCROLL_REDRAW had to be used instead. The only reason I can imagine so far
was that SCROLL_MOVE wasn't used by DRM and as such it was assumed that it
could go away. That argument completely missed the fact that SCROLL_MOVE is
still heavily used by fbdev (non-DRM) drivers.
Some people mention that using memcpy() instead of the hardware acceleration is
pretty much the same speed. But that's not true, at least not for older graphic
cards and machines where we see speed decreases by factor 10 and more and thus
this change leads to console responsiveness way worse than before.
That's why the original commit is to be reverted. By reverting we
reintroduce hardware-based scrolling acceleration and fix the
performance regression for fbdev drivers.
There isn't any impact on DRM when reverting those patches.
Signed-off-by: Helge Deller <deller@gmx.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Sven Schnelle <svens@stackframe.org>
Cc: stable@vger.kernel.org # v5.10+
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20220202135531.92183-3-deller@gmx.de
This reverts commit b3ec8cdf45.
Revert the second (of 2) commits which disabled scrolling acceleration
in fbcon/fbdev. It introduced a regression for fbdev-supported graphic
cards because of the performance penalty by doing screen scrolling by
software instead of using the existing graphic card 2D hardware
acceleration.
Console scrolling acceleration was disabled by dropping code which
checked at runtime the driver hardware capabilities for the
BINFO_HWACCEL_COPYAREA or FBINFO_HWACCEL_FILLRECT flags and if set, it
enabled scrollmode SCROLL_MOVE which uses hardware acceleration to move
screen contents. After dropping those checks scrollmode was hard-wired
to SCROLL_REDRAW instead, which forces all graphic cards to redraw every
character at the new screen position when scrolling.
This change effectively disabled all hardware-based scrolling acceleration for
ALL drivers, because now all kind of 2D hardware acceleration (bitblt,
fillrect) in the drivers isn't used any longer.
The original commit message mentions that only 3 DRM drivers (nouveau, omapdrm
and gma500) used hardware acceleration in the past and thus code for checking
and using scrolling acceleration is obsolete.
This statement is NOT TRUE, because beside the DRM drivers there are around 35
other fbdev drivers which depend on fbdev/fbcon and still provide hardware
acceleration for fbdev/fbcon.
The original commit message also states that syzbot found lots of bugs in fbcon
and thus it's "often the solution to just delete code and remove features".
This is true, and the bugs - which actually affected all users of fbcon,
including DRM - were fixed, or code was dropped like e.g. the support for
software scrollback in vgacon (commit 973c096f6a).
So to further analyze which bugs were found by syzbot, I've looked through all
patches in drivers/video which were tagged with syzbot or syzkaller back to
year 2005. The vast majority fixed the reported issues on a higher level, e.g.
when screen is to be resized, or when font size is to be changed. The few ones
which touched driver code fixed a real driver bug, e.g. by adding a check.
But NONE of those patches touched code of either the SCROLL_MOVE or the
SCROLL_REDRAW case.
That means, there was no real reason why SCROLL_MOVE had to be ripped-out and
just SCROLL_REDRAW had to be used instead. The only reason I can imagine so far
was that SCROLL_MOVE wasn't used by DRM and as such it was assumed that it
could go away. That argument completely missed the fact that SCROLL_MOVE is
still heavily used by fbdev (non-DRM) drivers.
Some people mention that using memcpy() instead of the hardware acceleration is
pretty much the same speed. But that's not true, at least not for older graphic
cards and machines where we see speed decreases by factor 10 and more and thus
this change leads to console responsiveness way worse than before.
That's why the original commit is to be reverted. By reverting we
reintroduce hardware-based scrolling acceleration and fix the
performance regression for fbdev drivers.
There isn't any impact on DRM when reverting those patches.
Signed-off-by: Helge Deller <deller@gmx.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Sven Schnelle <svens@stackframe.org>
Cc: stable@vger.kernel.org # v5.16+
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20220202135531.92183-2-deller@gmx.de
So ever since syzbot discovered fbcon, we have solid proof that it's
full of bugs. And often the solution is to just delete code and remove
features, e.g. 50145474f6 ("fbcon: remove soft scrollback code").
Now the problem is that most modern-ish drivers really only treat
fbcon as an dumb kernel console until userspace takes over, and Oops
printer for some emergencies. Looking at drm drivers and the basic
vesa/efi fbdev drivers shows that only 3 drivers support any kind of
acceleration:
- nouveau, seems to be enabled by default
- omapdrm, when a DMM remapper exists using remapper rewriting for
y/xpanning
- gma500, but that is getting deleted now for the GTT remapper trick,
and the accelerated copyarea never set the FBINFO_HWACCEL_COPYAREA
flag, so unused (and could be deleted already I think).
No other driver supportes accelerated fbcon. And fbcon is the only
user of this accel code (it's not exposed as uapi through ioctls),
which means we could garbage collect fairly enormous amounts of code
if we kill this.
Plus because syzbot only runs on virtual hardware, and none of the
drivers for that have acceleration, we'd remove a huge gap in testing.
And there's no other even remotely comprehensive testing aside from
syzbot.
This patch here just disables the acceleration code by always
redrawing when scrolling. The plan is that once this has been merged
for well over a year in released kernels, we can start to go around
and delete a lot of code.
v2:
- Drop a few more unused local variables, somehow I missed the
compiler warnings (Sam)
- Fix typo in comment (Jiri)
- add a todo entry for the cleanup (Thomas)
v3: Remove more unused variables (0day)
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: nouveau@lists.freedesktop.org
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Peilin Ye <yepeilin.cs@gmail.com>
Cc: George Kennedy <george.kennedy@oracle.com>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Peter Rosin <peda@axentia.se>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201029132229.4068359-1-daniel.vetter@ffwll.ch
For user-provided fonts, the framebuffer layer is using a magic
negative-indexing macro, FNTCHARCNT(), to keep track of their number of
characters:
#define FNTCHARCNT(fd) (((int *)(fd))[-3])
For built-in fonts, it is using hard-coded values (256). This results in
something like the following:
map.length = (ops->p->userfont) ?
FNTCHARCNT(ops->p->fontdata) : 256;
This is unsatisfactory. In fact, there is already a `charcount` field in
our virtual console descriptor (see `struct console_font` inside `struct
vc_data`), let us use it:
map.length = vc->vc_font.charcount;
Recently we added a `charcount` field to `struct font_desc`. Use it to set
`vc->vc_font.charcount` properly. The idea is:
- We only use FNTCHARCNT() on `vc->vc_font.data` and `p->fontdata`.
Assume FNTCHARCNT() is working as intended;
- Whenever `vc->vc_font.data` is set, also set `vc->vc_font.charcount`
properly;
- We can now replace `FNTCHARCNT(vc->vc_font.data)` with
`vc->vc_font.charcount`;
- Since `p->fontdata` always point to the same font data buffer with
`vc->vc_font.data`, we can also replace `FNTCHARCNT(p->fontdata)` with
`vc->vc_font.charcount`.
In conclusion, set `vc->vc_font.charcount` properly in fbcon_startup(),
fbcon_init(), fbcon_set_disp() and fbcon_do_set_font(), then replace
FNTCHARCNT() with `vc->vc_font.charcount`. No more if-else between
negative-indexing macros and hard-coded values.
Do not include <linux/font.h> in fbcon_rotate.c and tileblit.c, since they
no longer need it.
Depends on patch "Fonts: Add charcount field to font_desc".
Suggested-by: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/e460a5780e54e3022661d5f09555144583b4cc59.1605169912.git.yepeilin.cs@gmail.com
Pull drm updates from Dave Airlie:
"Not a major amount of change, the i915 trees got split into display
and gt trees to better facilitate higher level review, and there's a
major refactoring of i915 GEM locking to use more core kernel concepts
(like ww-mutexes). msm gets per-process pagetables, older AMD SI cards
get DC support, nouveau got a bump in displayport support with common
code extraction from i915.
Outside of drm this contains a couple of patches for hexint
moduleparams which you've acked, and a virtio common code tree that
you should also get via it's regular path.
New driver:
- Cadence MHDP8546 DisplayPort bridge driver
core:
- cross-driver scatterlist cleanups
- devm_drm conversions
- remove drm_dev_init
- devm_drm_dev_alloc conversion
ttm:
- lots of refactoring and cleanups
bridges:
- chained bridge support in more drivers
panel:
- misc new panels
scheduler:
- cleanup priority levels
displayport:
- refactor i915 code into helpers for nouveau
i915:
- split into display and GT trees
- WW locking refactoring in GEM
- execbuf2 extension mechanism
- syncobj timeline support
- GEN 12 HOBL display powersaving
- Rocket Lake display additions
- Disable FBC on Tigerlake
- Tigerlake Type-C + DP improvements
- Hotplug interrupt refactoring
amdgpu:
- Sienna Cichlid updates
- Navy Flounder updates
- DCE6 (SI) support for DC
- Plane rotation enabled
- TMZ state info ioctl
- PCIe DPC recovery support
- DC interrupt handling refactor
- OLED panel fixes
amdkfd:
- add SMI events for thermal throttling
- SMI interface events ioctl update
- process eviction counters
radeon:
- move to dma_ for allocations
- expose sclk via sysfs
msm:
- DSI support for sm8150/sm8250
- per-process GPU pagetable support
- Displayport support
mediatek:
- move HDMI phy driver to PHY
- convert mtk-dpi to bridge API
- disable mt2701 tmds
tegra:
- bridge support
exynos:
- misc cleanups
vc4:
- dual display cleanups
ast:
- cleanups
gma500:
- conversion to GPIOd API
hisilicon:
- misc reworks
ingenic:
- clock handling and format improvements
mcde:
- DSI support
mgag200:
- desktop g200 support
mxsfb:
- i.MX7 + i.MX8M
- alpha plane support
panfrost:
- devfreq support
- amlogic SoC support
ps8640:
- EDID from eDP retrieval
tidss:
- AM65xx YUV workaround
virtio:
- virtio-gpu exported resources
rcar-du:
- R8A7742, R8A774E1 and R8A77961 support
- YUV planar format fixes
- non-visible plane handling
- VSP device reference count fix
- Kconfig fix to avoid displaying disabled options in .config"
* tag 'drm-next-2020-10-15' of git://anongit.freedesktop.org/drm/drm: (1494 commits)
drm/ingenic: Fix bad revert
drm/amdgpu: Fix invalid number of character '{' in amdgpu_acpi_init
drm/amdgpu: Remove warning for virtual_display
drm/amdgpu: kfd_initialized can be static
drm/amd/pm: setup APU dpm clock table in SMU HW initialization
drm/amdgpu: prevent spurious warning
drm/amdgpu/swsmu: fix ARC build errors
drm/amd/display: Fix OPTC_DATA_FORMAT programming
drm/amd/display: Don't allow pstate if no support in blank
drm/panfrost: increase readl_relaxed_poll_timeout values
MAINTAINERS: Update entry for st7703 driver after the rename
Revert "gpu/drm: ingenic: Add option to mmap GEM buffers cached"
drm/amd/display: HDMI remote sink need mode validation for Linux
drm/amd/display: Change to correct unit on audio rate
drm/amd/display: Avoid set zero in the requested clk
drm/amdgpu: align frag_end to covered address space
drm/amdgpu: fix NULL pointer dereference for Renoir
drm/vmwgfx: fix regression in thp code due to ttm init refactor.
drm/amdgpu/swsmu: add interrupt work handler for smu11 parts
drm/amdgpu/swsmu: add interrupt work function
...
Pull tty/serial updates from Greg KH:
"Here is the big set of tty and serial driver patches for 5.10-rc1.
Lots of little things in here, including:
- tasklet_setup api conversions
- sysrq support for capital letters
- vt and vc cleanups and unwinding the mess some more
- serial driver updates and minor tweaks
- new device ids
- rs485 support for some drivers
- serial binding documentation updates
- lots of small serial driver changes for reported issues
All have been in linux-next for a while with no reported issues"
* tag 'tty-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (79 commits)
serial: mcf: add sysrq capability
serial: fsl_lpuart: add sysrq support when using dma
fbcon: remove no-op fbcon_set_origin()
tty/sysrq: Extend the sysrq_key_table to cover capital letters
serial: max310x: rework RX interrupt handling
serial: 8250_dw: Fix clk-notifier/port suspend deadlock
serial: 8250: Skip uninitialized TTY port baud rate update
serial: 8250: Discard RTS/DTS setting from clock update method
tty: serial: imx: disable TXDC IRQ in imx_uart_shutdown() to avoid IRQ storm
serial: 8250_fsl: Fix TX interrupt handling condition
serial: pl011: Fix lockdep splat when handling magic-sysrq interrupt
tty: serial: fsl_lpuart: fix lpuart32_poll_get_char
tty: serial: lpuart: fix lpuart32_write usage
serial: qcom_geni_serial: To correct QUP Version detection logic
serial: mvebu-uart: fix unused variable warning
vt_ioctl: make VT_RESIZEX behave like VT_RESIZE
serial: mvebu-uart: simplify the return expression of mvebu_uart_probe()
tty: serial: imx: fix link error with CONFIG_SERIAL_CORE_CONSOLE=n
tty: hvc: fix link error with CONFIG_SERIAL_CORE_CONSOLE=n
pch_uart: drop double zeroing
...
We need the tty/serial fixes in here and this resolves a merge issue in
the 8250 driver.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull tty/serial/fbcon fixes from Greg KH:
"Here are some small tty/serial and one more fbcon fix.
They include:
- serial core locking regression fixes
- new device ids for 8250_pci driver
- fbcon fix for syzbot found issue
All have been in linux-next with no reported issues"
* tag 'tty-5.9-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
fbcon: Fix user font detection test at fbcon_resize().
serial: 8250_pci: Add Realtek 816a and 816b
serial: core: fix console port-lock regression
serial: core: fix port-lock initialisation
This (and the VGA soft scrollback) turns out to have various nasty small
special cases that nobody really is willing to fight. The soft
scrollback code was really useful a few decades ago when you typically
used the console interactively as the main way to interact with the
machine, but that just isn't the case any more.
So it's not worth dragging along.
Tested-by: Yuan Ming <yuanmingbuaa@gmail.com>
Tested-by: Willy Tarreau <w@1wt.eu>
Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull tty/serial updates from Greg KH:
"Here is the large set of TTY and Serial driver patches for 5.9-rc1.
Lots of bugfixes in here, thanks to syzbot fuzzing for serial and vt
and console code.
Other highlights include:
- much needed vt/vc code cleanup from Jiri Slaby
- 8250 driver fixes and additions
- various serial driver updates and feature enhancements
- locking cleanup for serial/console initializations
- other minor cleanups
All of these have been in linux-next with no reported issues"
* tag 'tty-5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (90 commits)
MAINTAINERS: enlist Greg formally for console stuff
vgacon: Fix for missing check in scrollback handling
Revert "serial: 8250: Let serial core initialise spin lock"
serial: 8250: Let serial core initialise spin lock
tty: keyboard, do not speculate on func_table index
serial: stm32: Add RS485 RTS GPIO control
serial: 8250_dw: Fix common clocks usage race condition
serial: 8250_dw: Pass the same rate to the clk round and set rate methods
serial: 8250_dw: Simplify the ref clock rate setting procedure
serial: 8250: Add 8250 port clock update method
tty: serial: imx: add imx earlycon driver
tty: serial: imx: enable imx serial console port as module
tty/synclink: remove leftover bits of non-PCI card support
tty: Use the preferred form for passing the size of a structure type
tty: Fix identation issues in struct serial_struct32
tty: Avoid the use of one-element arrays
serial: msm_serial: add sparse context annotation
serial: pmac_zilog: add sparse context annotation
newport_con: vc_color is now in state
serial: imx: use hrtimers for rs485 delays
...
In the past we had a pile of hacks to orchestrate access between fbdev
emulation and native kms clients. We've tried to streamline this, by
always preferring the kms side above fbdev calls when a drm master
exists, because drm master controls access to the display resources.
Unfortunately this breaks existing userspace, specifically Xorg. When
exiting Xorg first restores the console to text mode using the KDSET
ioctl on the vt. This does nothing, because a drm master is still
around. Then it drops the drm master status, which again does nothing,
because logind is keeping additional drm fd open to be able to
orchestrate vt switches. In the past this is the point where fbdev was
restored, as part of the ->lastclose hook on the drm side.
Now to fix this regression we don't want to go back to letting fbdev
restore things whenever it feels like, or to the pile of hacks we've
had before. Instead try and go with a minimal exception to make the
KDSET case work again, and nothing else.
This means that if userspace does a KDSET call when switching between
graphical compositors, there will be some flickering with fbcon
showing up for a bit. But a) that's not a regression and b) userspace
can fix it by improving the vt switching dance - logind should have
all the information it needs.
While pondering all this I'm also wondering wheter we should have a
SWITCH_MASTER ioctl to allow race-free master status handover. But
that's for another day.
v2: Somehow forgot to cc all the fbdev people.
v3: Fix typo Alex spotted.
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=208179
Cc: shlomo@fastmail.com
Reported-and-Tested-by: shlomo@fastmail.com
Cc: Michel Dänzer <michel@daenzer.net>
Fixes: 64914da24e ("drm/fbdev-helper: don't force restores")
Cc: Noralf Trønnes <noralf@tronnes.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: dri-devel@lists.freedesktop.org
Cc: <stable@vger.kernel.org> # v5.7+
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Qiujun Huang <hqjagain@gmail.com>
Cc: Peter Rosin <peda@axentia.se>
Cc: linux-fbdev@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200624092910.3280448-1-daniel.vetter@ffwll.ch
There are two copies of some members of struct vc_data. This is because
we need to save them and restore later. Move these memebers to a
separate structure called vc_state. So now instead of members like:
vc_x, vc_y and vc_saved_x, vc_saved_y
we have
state and saved_state (of type: struct vc_state)
containing
state.x, state.y and saved_state.x, saved_state.y
This change:
* makes clear what is saved & restored
* eases save & restore by using memcpy (see save_cur and restore_cur)
Finally, we document the newly added struct vc_state using kernel-doc.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200615074910.19267-1-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Clang warns:
../drivers/video/fbdev/core/fbcon.c:915:3: warning: misleading
indentation; statement is not part of the previous 'if'
[-Wmisleading-indentation]
return err;
^
../drivers/video/fbdev/core/fbcon.c:912:2: note: previous statement is
here
if (!search_fb_in_map(info_idx))
^
1 warning generated.
This warning occurs because there is a space before the tab on this
line. This happens on several lines in this function; normalize them
so that the indentation is consistent with the Linux kernel coding
style and clang no longer warns.
This warning was introduced before the beginning of git history so no
fixes tab.
Link: https://github.com/ClangBuiltLinux/linux/issues/824
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191218025337.35044-1-natechancellor@gmail.com
These are actually fbcon ioctls which just happen to be exposed
through /dev/fb*. They completely ignore which fb_info they're called
on, and I think the userspace tool even hardcodes to /dev/fb0.
Hence just forward the entire thing to fbcon.c wholesale.
Note that this patch drops the fb_lock/unlock on the set side. Since
the ioctl can operate on any fb (as passed in through
con2fb.framebuffer) this is bogus. Also note that fbcon.c in general
never calls fb_lock on anything, so this has been badly broken
already.
With this the last user of the fbcon notifier callback is gone, and we
can garbage collect that too.
v2: add missing uaccess.h include (alpha fails to compile otherwise),
reported by kbuild.
v3: Remember to also drop the #defines (Maarten)
v4: Add the static inline to dummy functions.
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Yisheng Xie <ysxie@foxmail.com>
Cc: "Michał Mirosław" <mirq-linux@rere.qmqm.pl>
Cc: Peter Rosin <peda@axentia.se>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190528090304.9388-31-daniel.vetter@ffwll.ch
Ever since
commit c47747fde9
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date: Wed May 11 14:58:34 2011 -0700
fbmem: make read/write/ioctl use the frame buffer at open time
fbdev has gained proper refcounting for the fbinfo attached to any
open files, which means that the backing driver (stored in
fb_info->fbops) cannot untimely disappear anymore.
The only thing that can happen is that the entire device just outright
disappears and gets unregistered, but file_fb_info does check for
that. Except that it's racy - it only checks once at the start of a
file_ops, there's no guarantee that the underlying fbdev won't
untimely disappear. Aside: A proper way to fix that race is probably
to replicate the srcu trickery we've rolled out in drm.
But given that this race has existed since forever it's probably not
one we need to fix right away. do_unregister_framebuffer also nowhere
clears fb_info->fbops, hence the check in lock_fb_info can't possible
catch a disappearing fbdev later on.
Long story short: Ever since the above commit the fb_info->fbops
checks have essentially become dead code. Remove this all.
Aside from the file_ops callbacks, and stuff called from there
there's only register/unregister code left. If that goes wrong a driver
managed to register/unregister a device instance twice or in the wrong
order. That's just a driver bug.
v2:
- fb_mmap had an open-coded version of the fbinfo->fops check, because
it doesn't need the fbinfo->lock. Delete that too.
- Use the wrapper function in fb_open/release now, since no difference
anymore.
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Yisheng Xie <ysxie@foxmail.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: "Noralf Trønnes" <noralf@tronnes.org>
Cc: Peter Rosin <peda@axentia.se>
Cc: "Michał Mirosław" <mirq-linux@rere.qmqm.pl>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
Cc: linux-fbdev@vger.kernel.org
Link: https://patchwork.freedesktop.org/patch/msgid/20190528090304.9388-17-daniel.vetter@ffwll.ch
This is unused code since
commit 6104c37094
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Tue Aug 1 17:32:07 2017 +0200
fbcon: Make fbcon a built-time depency for fbdev
when fbcon was made a compile-time static dependency of fbdev. We
can't exit fbcon anymore without exiting fbdev first, which only works
if all fbdev drivers have unloaded already. Hence this is all dead
code.
v2: I missed that fbcon_exit is also called from con_deinit stuff, and
there fbcon_has_exited prevents double-cleanup. But we can fix that
by properly resetting con2fb_map[] to all -1, which is used everywhere
else to indicate "no fb_info allocate to this console". With that
change the double-cleanup (which resulted in a module refcount underflow,
among other things) is prevented.
Aside: con2fb_map is a signed char, so don't register more than 128 fb_info
or hilarity will ensue.
v3: CI showed me that I still didn't fully understand what's going on
here. The leaked references in con2fb_map have been used upon
rebinding the fb console in fbcon_init. It worked because fbdev
unregistering still cleaned out con2fb_map, and reset it to info_idx.
If the last fbdev driver unregistered, then it also reset info_idx,
and unregistered the fbcon driver.
Imo that's all a bit fragile, so let's keep the con2fb_map reset to
-1, and in fbcon_init pick info_idx if we're starting fresh. That
means unbinding and rebinding will cleanse the mapping, but why are
you doing that if you want to retain the mapping, so should be fine.
Also, I think info_idx == -1 is impossible in fbcon_init - we
unregister the fbcon in that case. So catch&warn about that.
v4: Drop unecessary assignment - I forgot to delete the first
assignment of info in fbcon_init.
Cc: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: "Noralf Trønnes" <noralf@tronnes.org>
Cc: Yisheng Xie <ysxie@foxmail.com>
Cc: Konstantin Khorenko <khorenko@virtuozzo.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190528090304.9388-10-daniel.vetter@ffwll.ch
