linux-toradex.git/drivers/video/console/fbcon.c, branch v3.2.68

fbcon: when font is freed, clear also vc_font.data

2013-05-13T14:02:24+00:00

commit e6637d5427d2af9f3f33b95447bfc5347e5ccd85 upstream.

commit ae1287865f5361fa138d4d3b1b6277908b54eac9
Author: Dave Airlie 
Date:   Thu Jan 24 16:12:41 2013 +1000

    fbcon: don't lose the console font across generic->chip driver switch

uses a pointer in vc->vc_font.data to load font into the new driver.
However if the font is actually freed, we need to clear the data
so that we don't reload font from dangling pointer.

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=892340
Signed-off-by: Mika Kuoppala 
Signed-off-by: Dave Airlie 
Signed-off-by: Ben Hutchings

fbcon: fix locking harder

2013-04-25T19:25:49+00:00

commit 054430e773c9a1e26f38e30156eff02dedfffc17 upstream.

Okay so Alan's patch handled the case where there was no registered fbcon,
however the other path entered in set_con2fb_map pit.

In there we called fbcon_takeover, but we also took the console lock in a couple
of places. So push the console lock out to the callers of set_con2fb_map,

this means fbmem and switcheroo needed to take the lock around the fb notifier
entry points that lead to this.

This should fix the efifb regression seen by Maarten.

Tested-by: Maarten Lankhorst 
Tested-by: Lu Hua 
Signed-off-by: Dave Airlie 
Signed-off-by: Ben Hutchings

fb: Yet another band-aid for fixing lockdep mess

2013-03-06T03:23:52+00:00

commit e93a9a868792ad71cdd09d75e5a02d8067473c4e upstream.

I've still got lockdep warnings even after Alan's patch, and it seems that
yet more band aids are required to paper over similar paths for
unbind_con_driver() and unregister_con_driver().  After this hack, lockdep
warnings are finally gone.

Signed-off-by: Takashi Iwai 
Cc: Alan Cox 
Cc: Florian Tobias Schandinat 
Cc: Jiri Kosina 
Tested-by: Sedat Dilek 
Signed-off-by: Andrew Morton 
Signed-off-by: Dave Airlie 
Signed-off-by: Ben Hutchings

fb: rework locking to fix lock ordering on takeover

2013-03-06T03:23:52+00:00

commit 50e244cc793d511b86adea24972f3a7264cae114 upstream.

Adjust the console layer to allow a take over call where the caller
already holds the locks.  Make the fb layer lock in order.

This is partly a band aid, the fb layer is terminally confused about the
locking rules it uses for its notifiers it seems.

[akpm@linux-foundation.org: remove stray non-ascii char, tidy comment]
[akpm@linux-foundation.org: export do_take_over_console()]
[airlied: cleanup another non-ascii char]
Signed-off-by: Alan Cox 
Cc: Florian Tobias Schandinat 
Cc: Stephen Rothwell 
Cc: Jiri Kosina 
Tested-by: Sedat Dilek 
Reviewed-by: Daniel Vetter 
Signed-off-by: Andrew Morton 
Signed-off-by: Dave Airlie 
Signed-off-by: Ben Hutchings

fbcon: don't lose the console font across generic->chip driver switch

2013-03-06T03:23:51+00:00

commit ae1287865f5361fa138d4d3b1b6277908b54eac9 upstream.

If grub2 loads efifb/vesafb, then when systemd starts it can set the console
font on that framebuffer device, however when we then load the native KMS
driver, the first thing it does is tear down the generic framebuffer driver.

The thing is the generic code is doing the right thing, it frees the font
because otherwise it would leak memory. However we can assume that if you
are removing the generic firmware driver (vesa/efi/offb), that a new driver
*should* be loading soon after, so we effectively leak the font.

However the old code left a dangling pointer in vc->vc_font.data and we
can now reuse that dangling pointer to load the font into the new
driver, now that we aren't freeing it.

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=892340

Cc: Kay Sievers 
Signed-off-by: Dave Airlie 
Signed-off-by: Ben Hutchings

fbcon: fix race condition between console lock and cursor timer (v1.1)

2012-09-12T02:37:24+00:00

commit d8636a2717bb3da2a7ce2154bf08de90bb8c87b0 upstream.

So we've had a fair few reports of fbcon handover breakage between
efi/vesafb and i915 surface recently, so I dedicated a couple of
days to finding the problem.

Essentially the last thing we saw was the conflicting framebuffer
message and that was all.

So after much tracing with direct netconsole writes (printks
under console_lock not so useful), I think I found the race.

Thread A (driver load)    Thread B (timer thread)
  unbind_con_driver ->              |
  bind_con_driver ->                |
  vc->vc_sw->con_deinit ->          |
  fbcon_deinit ->                   |
  console_lock()                    |
      |                             |
      |                       fbcon_flashcursor timer fires
      |                       console_lock() <- blocked for A
      |
      |
fbcon_del_cursor_timer ->
  del_timer_sync
  (BOOM)

Of course because all of this is under the console lock,
we never see anything, also since we also just unbound the active
console guess what we never see anything.

Hopefully this fixes the problem for anyone seeing vesafb->kms
driver handoff.

v1.1: add comment suggestion from Alan.

Signed-off-by: Dave Airlie 
Signed-off-by: Ben Hutchings

fbcon: Remove unused 'display *p' variable from fb_flashcursor()

2011-03-31T04:48:54+00:00

Signed-off-by: Sergey Senozhatsky 
Signed-off-by: Paul Mundt

fbcon: fix situation where fbcon gets deinitialised and can't reinit.

2011-03-22T08:22:19+00:00

Situation as follow:
2 GPUs + vesafb + kms.

GPU 1 is primary, vesafb binds to it as fb0
radeon loads
GPU 0 loads as fb1
GPU 1 loads, vesafb gets kicked off which causes fb0 to unbind
console, which causes the dummy console to rebind.

this means fbcon_deinit gets called, which calls fbcon_exit
since the console isn't bound anymore and we set fbcon_has_exited.

GPU 1 creates a new fb0 which is primary and we want to be console.
fbcon_fb_registered gets called sets the primary up and calls set_con2fb_map,
however as fbcon_has_exited is set nothing further ever happens.

This patch bypasses the fbcon_has_exited and checks if the console is unbound,
if its unbound it calls the fbcon_takeover which calls the vt layer to
call the fbcon_startup method and everthing works.

Signed-off-by: Dave Airlie 
Signed-off-by: Paul Mundt

console: rename acquire/release_console_sem() to console_lock/unlock()

2011-01-26T00:50:06+00:00

The -rt patches change the console_semaphore to console_mutex.  As a
result, a quite large chunk of the patches changes all
acquire/release_console_sem() to acquire/release_console_mutex()

This commit makes things use more neutral function names which dont make
implications about the underlying lock.

The only real change is the return value of console_trylock which is
inverted from try_acquire_console_sem()

This patch also paves the way to switching console_sem from a semaphore to
a mutex.

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: make console_trylock return 1 on success, per Geert]
Signed-off-by: Torben Hohn 
Cc: Thomas Gleixner 
Cc: Greg KH 
Cc: Ingo Molnar 
Cc: Geert Uytterhoeven 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fbcon: fix lockdep warning from fbcon_deinit()

2010-09-23T00:22:39+00:00

Fix the lockdep warning:

[   13.657164] INFO: trying to register non-static key.
[   13.657169] the code is fine but needs lockdep annotation.
[   13.657171] turning off the locking correctness validator.
[   13.657177] Pid: 622, comm: modprobe Not tainted 2.6.36-rc3c #8
[   13.657180] Call Trace:
[   13.657194]  [] ? printk+0x18/0x20
[   13.657202]  [] register_lock_class+0x336/0x350
[   13.657208]  [] __lock_acquire+0x449/0x1180
[   13.657215]  [] lock_acquire+0x67/0x80
[   13.657222]  [] ? __cancel_work_timer+0x51/0x230
[   13.657227]  [] __cancel_work_timer+0x83/0x230
[   13.657231]  [] ? __cancel_work_timer+0x51/0x230
[   13.657236]  [] ? mark_held_locks+0x62/0x80
[   13.657243]  [] ? kfree+0x7f/0xe0
[   13.657248]  [] ? trace_hardirqs_on_caller+0x11c/0x160
[   13.657253]  [] ? trace_hardirqs_on+0xb/0x10
[   13.657259]  [] ? fbcon_deinit+0x16d/0x1e0
[   13.657263]  [] ? fbcon_deinit+0x16d/0x1e0
[   13.657268]  [] cancel_work_sync+0xa/0x10
[   13.657272]  [] fbcon_deinit+0xe4/0x1e0
...

The warning is caused by trying to cancel an uninitialized work from
fbcon_exit().  Fix it by adding a check for queue.func, similarly to other
places in this code.

Signed-off-by: Jarek Poplawski 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds