linux.git/drivers/video/fbdev/core/fbmem.c, branch v4.20

fbdev: Add FBINFO_HIDE_SMEM_START flag

2018-09-11T12:11:54+00:00

DRM drivers really, really, really don't want random userspace to
share buffer behind it's back, bypassing the dma-buf buffer sharing
machanism. For that reason we've ruthlessly rejected any IOCTL
exposing the physical address of any graphics buffer.

Unfortunately fbdev comes with that built-in. We could just set
smem_start to 0, but that means we'd have to hand-roll our own fb_mmap
implementation. For good reasons many drivers do that, but
smem_start/length is still super convenient.

Hence instead just stop the leak in the ioctl, to keep fb mmap working
as-is. A second patch will set this flag for all drm drivers.

Acked-by: Bartlomiej Zolnierkiewicz 
Cc: Bartlomiej Zolnierkiewicz 
Cc: Kees Cook 
Cc: Daniel Vetter 
Cc: linux-fbdev@vger.kernel.org
Signed-off-by: Daniel Vetter 
Link: https://patchwork.freedesktop.org/patch/msgid/20180822085405.10787-3-daniel.vetter@ffwll.ch

fbdev: fix kerneldoc

2018-09-07T19:49:13+00:00

As noticed by kbuild test robot ,
remove_conflicting_pci_framebuffers()'s second argument
is called res_id not resource_id. Fix this.

Signed-off-by: Michał Mirosław 
Signed-off-by: Daniel Vetter 
Link: https://patchwork.freedesktop.org/patch/msgid/38ca9044455a33e398b45e0281643cc24da3c2fc.1536342224.git.mirq-linux@rere.qmqm.pl

fbdev: add remove_conflicting_pci_framebuffers()

2018-09-03T16:15:40+00:00

Almost all PCI drivers using remove_conflicting_framebuffers() wrap it
with the same code.

v2: add kerneldoc for DRM helper
v3: propagate remove_conflicting_framebuffers() return value
  + move kerneldoc to where function is implemented

Signed-off-by: Michał Mirosław 
Acked-by: Bartlomiej Zolnierkiewicz 
Signed-off-by: Daniel Vetter 
Link: https://patchwork.freedesktop.org/patch/msgid/7db1c278276de420eb45a1b71d06b5eb6bbd49ef.1535810304.git.mirq-linux@rere.qmqm.pl

fbdev: add kerneldoc do remove_conflicting_framebuffers()

2018-09-03T16:15:26+00:00

Document remove_conflicting_framebuffers() behaviour.

Signed-off-by: Michał Mirosław 
Acked-by: Bartlomiej Zolnierkiewicz 
Signed-off-by: Daniel Vetter 
Link: https://patchwork.freedesktop.org/patch/msgid/283fef19815b991700b56119d8d5874a2a8da44e.1535810304.git.mirq-linux@rere.qmqm.pl

fbdev: allow apertures == NULL in remove_conflicting_framebuffers()

2018-09-03T16:14:55+00:00

Interpret (otherwise-invalid) NULL apertures argument to mean all-memory
range. This will allow to remove several duplicates of this code
from drivers in following patches.

Signed-off-by: Michał Mirosław 
Acked-by: Bartlomiej Zolnierkiewicz 
Signed-off-by: Daniel Vetter 
Link: https://patchwork.freedesktop.org/patch/msgid/b5fed539fe569035139c8594c23effd8c39f12ca.1535810304.git.mirq-linux@rere.qmqm.pl

fbdev: show fbdev number for debugging

2018-09-03T16:14:42+00:00

Signed-off-by: Michał Mirosław 
Acked-by: Bartlomiej Zolnierkiewicz 
Acked-by: Daniel Vetter 
Signed-off-by: Daniel Vetter 
Link: https://patchwork.freedesktop.org/patch/msgid/ef584ecd8642e8b1a04f28d6d9c1864b5aa507bb.1535810304.git.mirq-linux@rere.qmqm.pl

fbdev/core: Disable console-lock warnings when fb.lockless_register_fb is set

2018-07-31T11:06:58+00:00

If the console is unlocked during registration, the console subsystem
generates significant amounts of warnings, which obfuscate actual
debugging messages. Setting ignore_console_lock_warning while debugging
console registration avoid the noise.

v3:
	- manipulate ignore_console_lock_warning with atomic_{inc,dec}
v2:
	- restore ignore_console_lock_warning if lock_fb_info() fails

Signed-off-by: Thomas Zimmermann 
Acked-by: Hans de Goede 
Reviewed-by: Petr Mladek 
Reviewed-by: Sergey Senozhatsky 
Cc: Steven Rostedt (VMware) 
Cc: Andrew Morton 
Signed-off-by: Bartlomiej Zolnierkiewicz

fb: fix lost console when the user unplugs a USB adapter

2018-07-25T13:41:54+00:00

I have a USB display adapter using the udlfb driver and I use it on an ARM
board that doesn't have any graphics card. When I plug the adapter in, the
console is properly displayed, however when I unplug and re-plug the
adapter, the console is not displayed and I can't access it until I reboot
the board.

The reason is this:
When the adapter is unplugged, dlfb_usb_disconnect calls
unlink_framebuffer, then it waits until the reference count drops to zero
and then it deallocates the framebuffer. However, the console that is
attached to the framebuffer device keeps the reference count non-zero, so
the framebuffer device is never destroyed. When the USB adapter is plugged
again, it creates a new device /dev/fb1 and the console is not attached to
it.

This patch fixes the bug by unbinding the console from unlink_framebuffer.
The code to unbind the console is moved from do_unregister_framebuffer to
a function unbind_console. When the console is unbound, the reference
count drops to zero and the udlfb driver frees the framebuffer. When the
adapter is plugged back, a new framebuffer is created and the console is
attached to it.

Signed-off-by: Mikulas Patocka 
Cc: Dave Airlie 
Cc: Bernie Thompson 
Cc: Ladislav Michl 
Cc: stable@vger.kernel.org
[b.zolnierkie: preserve old behavior for do_unregister_framebuffer()]
Signed-off-by: Bartlomiej Zolnierkiewicz

fbdev: fbmem: mark expected switch fall-through

2018-07-24T17:11:27+00:00

In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.

Signed-off-by: Gustavo A. R. Silva 
Signed-off-by: Bartlomiej Zolnierkiewicz

fbcon: introduce for_each_registered_fb() helper

2018-07-24T17:11:26+00:00

Following pattern is often used:

 for (i = 0; i < FB_MAX; i++) {
        if (registered_fb[i]) {
                ...
        }
 }

Therefore, as Andy's suggestion, for_each_registered_fb() helper can
be introduced to make the code easier to read and write by reducing
indentation level. It also saves few lines of code in each occurrence.

This patch convert all part here at the same time.

Suggested-by: Andy Shevchenko 
Signed-off-by: Yisheng Xie 
Acked-by: Hans de Goede 
Reviewed-by: Andy Shevchenko 
Cc: Kees Cook 
Cc: David Lechner 
Signed-off-by: Bartlomiej Zolnierkiewicz