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  1. 23 Feb, 2022 2 commits
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  19. 02 Feb, 2022 3 commits
    • Helge Deller's avatar
      fbcon: Add option to enable legacy hardware acceleration · a3f781a9
      Helge Deller authored 
      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: default avatarHelge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # v5.10+
Signed-off-by: default avatarHelge Deller <deller@gmx.de>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20220202135531.92183-4-deller@gmx.de
      a3f781a9
    • Helge Deller's avatar
      Revert "fbcon: Disable accelerated scrolling" · 87ab9f6b
      Helge Deller authored 
      This reverts commit 39aead83.

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 973c096f).

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: default avatarHelge Deller <deller@gmx.de>
Acked-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
Acked-by: default avatarSven Schnelle <svens@stackframe.org>
Cc: stable@vger.kernel.org # v5.10+
Signed-off-by: default avatarHelge Deller <deller@gmx.de>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20220202135531.92183-3-deller@gmx.de
      87ab9f6b
    • Helge Deller's avatar
      Revert "fbdev: Garbage collect fbdev scrolling acceleration, part 1 (from TODO list)" · 1148836f
      Helge Deller authored 
      This reverts commit b3ec8cdf.

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 973c096f).

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: default avatarHelge Deller <deller@gmx.de>
Acked-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
Acked-by: default avatarSven Schnelle <svens@stackframe.org>
Cc: stable@vger.kernel.org # v5.16+
Signed-off-by: default avatarHelge Deller <deller@gmx.de>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20220202135531.92183-2-deller@gmx.de
      1148836f
  21. 01 Feb, 2022 1 commit
  23. 31 Jan, 2022 1 commit
  25. 27 Jan, 2022 1 commit
    • Anitha Chrisanthus's avatar
      drm/kmb: Fix for build errors with Warray-bounds · 43f25179
      Anitha Chrisanthus authored 
      This fixes the following build error

drivers/gpu/drm/kmb/kmb_plane.c: In function 'kmb_plane_atomic_disable':
drivers/gpu/drm/kmb/kmb_plane.c:165:34: error: array subscript 3 is above array bounds of 'struct layer_status[2]' [-Werror=array-bounds]
  165 |                 kmb->plane_status[plane_id].ctrl =
  LCD_CTRL_GL2_ENABLE;
  |                 ~~~~~~~~~~~~~~~~~^~~~~~~~~~
  In file included from drivers/gpu/drm/kmb/kmb_plane.c:17:
  drivers/gpu/drm/kmb/kmb_drv.h:61:41: note: while referencing 'plane_status'
  61 |         struct layer_status  plane_status[KMB_MAX_PLANES];
  |                                         ^~~~~~~~~~~~
  drivers/gpu/drm/kmb/kmb_plane.c:162:34: error: array subscript 2 is above array bounds of 'struct layer_status[2]' [-Werror=array-bounds]
  162 |  kmb->plane_status[plane_id].ctrl =  LCD_CTRL_GL1_ENABLE;
  |                 ~~~~~~~~~~~~~~~~~^~~~~~~~~~
  In file included from
  drivers/gpu/drm/kmb/kmb_plane.c:17:
  drivers/gpu/drm/kmb/kmb_drv.h:61:41: note: while referencing 'plane_status'
  61 |         struct layer_status  plane_status[KMB_MAX_PLANES];
  |
  ^~~~~~~~~~~~

Fixes: 7f7b96a8 ("drm/kmb: Add support for KeemBay Display")
Signed-off-by: default avatarAnitha Chrisanthus <anitha.chrisanthus@intel.com>
Reviewed-by: default avatarKees Cook <keescook@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220127194227.2213608-1-anitha.chrisanthus@intel.com
      43f25179
  27. 26 Jan, 2022 3 commits
  29. 25 Jan, 2022 1 commit
  31. 23 Jan, 2022 6 commits
    • Linus Torvalds's avatar
      Linux 5.17-rc1 · e783362e
      Linus Torvalds authored
      e783362e
    • Linus Torvalds's avatar
      Merge tag 'perf-tools-for-v5.17-2022-01-22' of... · 40c84321
      Linus Torvalds authored 
      Merge tag 'perf-tools-for-v5.17-2022-01-22' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux

Pull more perf tools updates from Arnaldo Carvalho de Melo:

 - Fix printing 'phys_addr' in 'perf script'.

 - Fix failure to add events with 'perf probe' in ppc64 due to not
   removing leading dot (ppc64 ABIv1).

 - Fix cpu_map__item() python binding building.

 - Support event alias in form foo-bar-baz, add pmu-events and
   parse-event tests for it.

 - No need to setup affinities when starting a workload or attaching to
   a pid.

 - Use path__join() to compose a path instead of ad-hoc snprintf()
   equivalent.

 - Override attr->sample_period for non-libpfm4 events.

 - Use libperf cpumap APIs instead of accessing the internal state
   directly.

 - Sync x86 arch prctl headers and files changed by the new
   set_mempolicy_home_node syscall with the kernel sources.

 - Remove duplicate include in cpumap.h.

 - Remove redundant err variable.

* tag 'perf-tools-for-v5.17-2022-01-22' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux:
  perf tools: Remove redundant err variable
  perf test: Add parse-events test for aliases with hyphens
  perf test: Add pmu-events test for aliases with hyphens
  perf parse-events: Support event alias in form foo-bar-baz
  perf evsel: Override attr->sample_period for non-libpfm4 events
  perf cpumap: Remove duplicate include in cpumap.h
  perf cpumap: Migrate to libperf cpumap api
  perf python: Fix cpu_map__item() building
  perf script: Fix printing 'phys_addr' failure issue
  tools headers UAPI: Sync files changed by new set_mempolicy_home_node syscall
  tools headers UAPI: Sync x86 arch prctl headers with the kernel sources
  perf machine: Use path__join() to compose a path instead of snprintf(dir, '/', filename)
  perf evlist: No need to setup affinities when disabling events for pid targets
  perf evlist: No need to setup affinities when enabling events for pid targets
  perf stat: No need to setup affinities when starting a workload
  perf affinity: Allow passing a NULL arg to affinity__cleanup()
  perf probe: Fix ppc64 'perf probe add events failed' case
      40c84321
    • Linus Torvalds's avatar
      Merge tag 'trace-v5.17-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace · 67bfce0e
      Linus Torvalds authored 
      Pull ftrace fix from Steven Rostedt:
 "Fix s390 breakage from sorting mcount tables.

  The latest merge of the tracing tree sorts the mcount table at build
  time. But s390 appears to do things differently (like always) and
  replaces the sorted table back to the original unsorted one. As the
  ftrace algorithm depends on it being sorted, bad things happen when it
  is not, and s390 experienced those bad things.

  Add a new config to tell the boot if the mcount table is sorted or
  not, and allow s390 to opt out of it"

* tag 'trace-v5.17-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace: Fix assuming build time sort works for s390
      67bfce0e
    • Steven Rostedt (Google)'s avatar
      ftrace: Fix assuming build time sort works for s390 · 6b9b6413
      Steven Rostedt (Google) authored 
      To speed up the boot process, as mcount_loc needs to be sorted for ftrace
to work properly, sorting it at build time is more efficient than boot up
and can save milliseconds of time. Unfortunately, this change broke s390
as it will modify the mcount_loc location after the sorting takes place
and will put back the unsorted locations. Since the sorting is skipped at
boot up if it is believed that it was sorted at run time, ftrace can crash
as its algorithms are dependent on the list being sorted.

Add a new config BUILDTIME_MCOUNT_SORT that is set when
BUILDTIME_TABLE_SORT but not if S390 is set. Use this config to determine
if sorting should take place at boot up.

Link: https://lore.kernel.org/all/yt9dee51ctfn.fsf@linux.ibm.com/

Fixes: 72b3942a ("scripts: ftrace - move the sort-processing in ftrace_init")
Reported-by: default avatarSven Schnelle <svens@linux.ibm.com>
Tested-by: default avatarHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
      6b9b6413
    • Linus Torvalds's avatar
      Merge tag 'kbuild-fixes-v5.17' of... · 473aec0e
      Linus Torvalds authored 
      Merge tag 'kbuild-fixes-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild fixes from Masahiro Yamada:

 - Bring include/uapi/linux/nfc.h into the UAPI compile-test coverage

 - Revert the workaround of CONFIG_CC_IMPLICIT_FALLTHROUGH

 - Fix build errors in certs/Makefile

* tag 'kbuild-fixes-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  certs: Fix build error when CONFIG_MODULE_SIG_KEY is empty
  certs: Fix build error when CONFIG_MODULE_SIG_KEY is PKCS#11 URI
  Revert "Makefile: Do not quote value for CONFIG_CC_IMPLICIT_FALLTHROUGH"
  usr/include/Makefile: add linux/nfc.h to the compile-test coverage
      473aec0e
    • Linus Torvalds's avatar
      Merge tag 'bitmap-5.17-rc1' of git://github.com/norov/linux · 3689f9f8
      Linus Torvalds authored 
      Pull bitmap updates from Yury Norov:

 - introduce for_each_set_bitrange()

 - use find_first_*_bit() instead of find_next_*_bit() where possible

 - unify for_each_bit() macros

* tag 'bitmap-5.17-rc1' of git://github.com/norov/linux:
  vsprintf: rework bitmap_list_string
  lib: bitmap: add performance test for bitmap_print_to_pagebuf
  bitmap: unify find_bit operations
  mm/percpu: micro-optimize pcpu_is_populated()
  Replace for_each_*_bit_from() with for_each_*_bit() where appropriate
  find: micro-optimize for_each_{set,clear}_bit()
  include/linux: move for_each_bit() macros from bitops.h to find.h
  cpumask: replace cpumask_next_* with cpumask_first_* where appropriate
  tools: sync tools/bitmap with mother linux
  all: replace find_next{,_zero}_bit with find_first{,_zero}_bit where appropriate
  cpumask: use find_first_and_bit()
  lib: add find_first_and_bit()
  arch: remove GENERIC_FIND_FIRST_BIT entirely
  include: move find.h from asm_generic to linux
  bitops: move find_bit_*_le functions from le.h to find.h
  bitops: protect find_first_{,zero}_bit properly
      3689f9f8
  33. 22 Jan, 2022 5 commits
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