linux-stable.git/include/linux/fb.h, branch v6.2.9

fbdev: Fix incorrect page mapping clearance at fb_deferred_io_release()

2023-03-22T12:38:08+00:00

commit fe9ae05cfbe587dda724fcf537c00bc2f287da62 upstream.

The recent fix for the deferred I/O by the commit
  3efc61d95259 ("fbdev: Fix invalid page access after closing deferred I/O devices")
caused a regression when the same fb device is opened/closed while
it's being used.  It resulted in a frozen screen even if something
is redrawn there after the close.  The breakage is because the patch
was made under a wrong assumption of a single open; in the current
code, fb_deferred_io_release() cleans up the page mapping of the
pageref list and it calls cancel_delayed_work_sync() unconditionally,
where both are no correct behavior for multiple opens.

This patch adds a refcount for the opens of the device, and applies
the cleanup only when all files get closed.

As both fb_deferred_io_open() and _close() are called always in the
fb_info lock (mutex), it's safe to use the normal int for the
refcounting.

Also, a useless BUG_ON() is dropped.

Fixes: 3efc61d95259 ("fbdev: Fix invalid page access after closing deferred I/O devices")
Cc: 
Signed-off-by: Takashi Iwai 
Reviewed-by: Patrik Jakobsson 
Signed-off-by: Thomas Zimmermann 
Link: https://patchwork.freedesktop.org/patch/msgid/20230308105012.1845-1-tiwai@suse.de
Signed-off-by: Greg Kroah-Hartman

fbdev: Fix invalid page access after closing deferred I/O devices

2023-02-10T10:03:37+00:00

When a fbdev with deferred I/O is once opened and closed, the dirty
pages still remain queued in the pageref list, and eventually later
those may be processed in the delayed work.  This may lead to a
corruption of pages, hitting an Oops.

This patch makes sure to cancel the delayed work and clean up the
pageref list at closing the device for addressing the bug.  A part of
the cleanup code is factored out as a new helper function that is
called from the common fb_release().

Reviewed-by: Patrik Jakobsson 
Cc: 
Signed-off-by: Takashi Iwai 
Tested-by: Miko Larsson 
Fixes: 56c134f7f1b5 ("fbdev: Track deferred-I/O pages in pageref struct")
Reviewed-by: Thomas Zimmermann 
Signed-off-by: Thomas Zimmermann 
Link: https://patchwork.freedesktop.org/patch/msgid/20230129082856.22113-1-tiwai@suse.de

Merge tag 'drm-misc-next-fixes-2022-12-08' of git://anongit.freedesktop.org/drm/drm-misc into drm-next

2022-12-09T01:53:52+00:00

Some deferred-io and damage worker reworks revert and make a fb function
static

Signed-off-by: Dave Airlie 

From: Maxime Ripard 
Link: https://patchwork.freedesktop.org/patch/msgid/20221208084040.yw4zavsjd25qsltf@houat

Backmerge tag 'v6.1-rc6' into drm-next

2022-11-24T01:05:43+00:00

Linux 6.1-rc6

This is needed for drm-misc-next and tegra.

Signed-off-by: Dave Airlie

Revert "drm/fb-helper: Schedule deferred-I/O worker after writing to framebuffer"

2022-11-23T08:11:00+00:00

This reverts commit 7f5cc4a3e5e4c5a38e5748defc952e45278f7a70.

Needed to restore the fbdev damage worker. There have been bug reports
about locking order [1] and incorrectly takens branches. [2] Restore
the damage worker until these problems have been resovled.

Signed-off-by: Thomas Zimmermann 
Acked-by: Daniel Vetter 
Link: https://intel-gfx-ci.01.org/tree/drm-tip/fi-kbl-8809g.html # 1
Link: https://lore.kernel.org/dri-devel/20221115115819.23088-6-tzimmermann@suse.de/T/#m06eedc0a468940e4cbbd14ca026733b639bc445a # 2
Link: https://patchwork.freedesktop.org/patch/msgid/20221118133535.9739-3-tzimmermann@suse.de
(cherry picked from commit 8b83e1a455382dc667898a525a93f4eb6716cc41)

fbdev: Make fb_modesetting_disabled() static inline

2022-11-23T08:09:40+00:00

Make fb_modesetting_disabled() a static-inline function when it is
defined in the header file. Avoid the linker error shown below.

 ld: drivers/video/fbdev/core/fbmon.o: in function `fb_modesetting_disabled':
 fbmon.c:(.text+0x1e4): multiple definition of `fb_modesetting_disabled'; drivers/video/fbdev/core/fbmem.o:fbmem.c:(.text+0x1bac): first defined here

A bug report is at [1].

Reported-by: Stephen Rothwell 
Reported-by: kernel test robot 
Signed-off-by: Thomas Zimmermann 
Reviewed-by: Javier Martinez Canillas 
Fixes: 0ba2fa8cbd29 ("fbdev: Add support for the nomodeset kernel parameter")
Cc: Javier Martinez Canillas 
Cc: Daniel Vetter 
Cc: Helge Deller 
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Link: https://lore.kernel.org/dri-devel/20221117183214.2473e745@canb.auug.org.au/T/#u # 1
Link: https://patchwork.freedesktop.org/patch/msgid/20221117114729.7570-1-tzimmermann@suse.de
(cherry picked from commit a189b2ee938f6b15ad9f95bdef63f95a3a092418)

fbdev: Add support for the nomodeset kernel parameter

2022-11-16T12:26:25+00:00

Support the kernel's nomodeset parameter for all PCI-based fbdev
drivers that use aperture helpers to remove other, hardware-agnostic
graphics drivers.

The parameter is a simple way of using the firmware-provided scanout
buffer if the hardware's native driver is broken. The same effect
could be achieved with per-driver options, but the importance of the
graphics output for many users makes a single, unified approach
worthwhile.

With nomodeset specified, the fbdev driver module will not load. This
unifies behavior with similar DRM drivers. In DRM helpers, modules
first check the nomodeset parameter before registering the PCI
driver. As fbdev has no such module helpers, we have to modify each
driver individually.

The name 'nomodeset' is slightly misleading, but has been chosen for
historical reasons. Several drivers implemented it before it became a
general option for DRM. So keeping the existing name was preferred over
introducing a new one.

v2:
	* print a warning if a driver does not init (Helge)
	* wrap video_firmware_drivers_only() in helper

Signed-off-by: Thomas Zimmermann 
Reviewed-by: Javier Martinez Canillas 
Link: https://patchwork.freedesktop.org/patch/msgid/20221111133024.9897-3-tzimmermann@suse.de

drm/fb-helper: Schedule deferred-I/O worker after writing to framebuffer

2022-11-16T12:22:24+00:00

Schedule the deferred-I/O worker instead of the damage worker after
writing to the fbdev framebuffer. The deferred-I/O worker then performs
the dirty-fb update. The fbdev emulation will initialize deferred I/O
for all drivers that require damage updates. It is therefore a valid
assumption that the deferred-I/O worker is present.

It would be possible to perform the damage handling directly from within
the write operation. But doing this could increase the overhead of the
write or interfere with a concurrently scheduled deferred-I/O worker.
Instead, scheduling the deferred-I/O worker with its regular delay of
50 ms removes load off the write operation and allows the deferred-I/O
worker to handle multiple write operations that arrived during the delay
time window.

v3:
	* remove unused variable (lkp)
v2:
	* keep drm_fb_helper_damage() (Daniel)
	* use fb_deferred_io_schedule_flush() (Daniel)
	* clarify comments (Daniel)

Signed-off-by: Thomas Zimmermann 
Reviewed-by: Daniel Vetter 
Link: https://patchwork.freedesktop.org/patch/msgid/20221115115819.23088-6-tzimmermann@suse.de

fbdev: MIPS supports iomem addresses

2022-10-17T11:49:45+00:00

Add MIPS to fb_* helpers list for iomem addresses. This silences Sparse
warnings about lacking __iomem address space casts:

drivers/video/fbdev/pvr2fb.c:800:9: sparse: sparse: incorrect type in argument 1 (different address spaces)
drivers/video/fbdev/pvr2fb.c:800:9: sparse:     expected void const *
drivers/video/fbdev/pvr2fb.c:800:9: sparse:     got char [noderef] __iomem *screen_base

Reported-by: kernel test robot 
Link: https://lore.kernel.org/lkml/202210100209.tR2Iqbqk-lkp@intel.com/
Cc: Helge Deller 
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Kees Cook 
Signed-off-by: Helge Deller

fbdev: Make registered_fb[] private to fbmem.c

2022-07-27T07:40:18+00:00

No driver access this anymore, except for the olpc dcon fbdev driver but
that has been marked as broken anyways by commit de0952f267ff ("staging:
olpc_dcon: mark driver as broken").

Signed-off-by: Daniel Vetter 
Signed-off-by: Daniel Vetter 
Reviewed-by: Javier Martinez Canillas 
Signed-off-by: Javier Martinez Canillas 
Signed-off-by: Thomas Zimmermann 
Acked-by: Thomas Zimmermann 
Link: https://patchwork.freedesktop.org/patch/msgid/20220725075400.68478-1-javierm@redhat.com