linux-toradex.git/drivers/video/console/fbcon.c, branch v2.6.32.2

fb: remove fb_save_state() and fb_restore_state operations

2009-11-12T15:25:56+00:00

Remove fb_save_state() and fb_restore_state operations from frame buffer layer.
They are used only in two drivers:
1. savagefb  - and cause bug #11248
2. uvesafb

Usage of these operations is misunderstood in both drivers so kill these
operations, fix the bug #11248 and avoid confusion in the future.

Tested on Savage 3D/MV card and the patch fixes the bug #11248.

The frame buffer layer uses these funtions during switch between graphics
and text mode of the console, but these drivers saves state before
switching of the frame buffer (in the fb_open) and after releasing it (in
the fb_release).  This defeats the purpose of these operations.

Addresses http://bugzilla.kernel.org/show_bug.cgi?id=11248

Signed-off-by: Krzysztof Helt 
Reported-by: Jochen Hein 
Tested-by: Jochen Hein 
Cc: Geert Uytterhoeven 
Cc: Michal Januszewski 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fbcon: only unbind from console if successfully registered

2009-09-23T14:39:57+00:00

Attempting to unload a framebuffer module calls unregister_framebuffer()
which in turn gets fbcon to release it.  If fbcon has no framebuffers
linked to a console, it will also unbind itself from the console driver.
However, if fbcon never registered itself as a console driver, the unbind
will fail causing the framebuffer device entry to persist.  In most cases
this failure will result in an oops when attempting to access the now
non-existent device.

This patch ensures that the fbcon unbind request will succeed even if a
bind was never done.  It tracks if a successful bind ever occurred & will
only attempt to unbind if needed.  If there never was a bind, it simply
returns with no error.

Signed-off-by: Ian Armstrong 
Cc: Krzysztof Helt 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fb: do not ignore fb_set_par errors

2009-09-23T14:39:56+00:00

At the moment about half of the framebuffer drivers can return an error
code in fb_set_par. Until now it would be silently ignored by fbmem.c
and fbcon.c. This patch fixes fbmem.c to return the error code and
restore var on error.

But it is not clear in which video mode the device is when fb_set_par
fails.  It would be good and reasonable if it were in the old state but
there is no guarantee that this is true for all existing drivers.
Additionally print a message if a failing fb_set_par is detected in
fbmem.c or fbcon.c.

Although most errors should be caught by the previous fb_check_var some
errors can't as they are dynamic (memory allocations, ...) and can only be
detected while performing the operations which is forbidden in
fb_check_var.

This patch shouldn't have a negative impact on normal operation as all
drivers return 0 on success.  The impact in case of error depends heavily
on the driver and caller but it's expected to be better than before.

Signed-off-by: Florian Tobias Schandinat 
Cc: Krzysztof Helt 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fbcon: don't use vc_resize() on initialization

2009-08-07T17:39:56+00:00

Catalin and kmemleak spotted a leak of a VC screen buffer in
vc_allocate() due to the following chain of events:

	vc_allocate()
	  visual_init(init=1)
	    vc->vc_sw->con_init(init=1)
              fbcon_init()
	        vc_resize()
	          vc->screen_buf = kmalloc()
	  vc->screen_buf = kmalloc()

The common way for the VC drivers is to set the screen dimension
parameters manually in the init case and only call vc_resize() for
!init - which allocates a screen buffer according to the new
dimensions.

fbcon instead would do vc_resize() unconditionally and afterwards set
the dimensions manually (again) for !init - i.e. completely upside
down.  The vc_resize() allocated buffer would then get lost by
vc_allocate() allocating a fresh one.

Use vc_resize() only for actual resizing to close the leak.

Set the dimensions manually only in initialization mode to remove the
redundant setting in resize mode.

The kmemleak trace from Catalin:

unreferenced object 0xde158000 (size 12288):
  comm "Xorg", pid 1439, jiffies 4294961016
  hex dump (first 32 bytes):
    20 00 20 00 20 00 20 00 20 00 20 00 20 00 20 00   . . . . . . . .
    20 00 20 00 20 00 20 00 20 00 20 00 20 00 20 00   . . . . . . . .
  backtrace:
    [] __save_stack_trace+0x17/0x1c
    [] create_object+0xcd/0x188
    [] kmemleak_alloc+0x1b/0x3c
    [] __kmalloc+0xdb/0xe8
    [] vc_do_resize+0x73/0x1e0
    [] vc_resize+0x15/0x18
    [] fbcon_init+0x1f9/0x2b8
    [] visual_init+0x9f/0xdc
    [] vc_allocate+0x7f/0xfc
    [] con_open+0x17/0x80
    [] tty_open+0x1f7/0x2e4
    [] chrdev_open+0x101/0x118
    [] __dentry_open+0x105/0x1cc
    [] nameidata_to_filp+0x2d/0x38
    [] do_filp_open+0x2c1/0x54c
    [] do_sys_open+0x3b/0xb4

Reported-by: Catalin Marinas 
Signed-off-by: Johannes Weiner 
Tested-by: Catalin Marinas 
Cc: Pekka Enberg 
Cc: Krzysztof Helt 
Tested-by: Dave Young 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fbdev: fix info->lock deadlock in fbcon_event_notify()

2009-04-13T22:04:28+00:00

fb_notifier_call_chain() is called with info->lock held, i.e.  in
do_fb_ioctl() => FBIOPUT_VSCREENINFO => fb_set_var() and the some
notifier callbacks, like fbcon_event_notify(), try to re-acquire
info->lock again.

Remove the lock/unlock_fb_info() in all the framebuffer notifier
callbacks' and be sure to always call fb_notifier_call_chain() with
info->lock held.

Reported-by: Pavel Roskin 
Reported-by: Eric Miao 
Signed-off-by: Andrea Righi 
Cc: Stefan Richter 
Cc: Krzysztof Helt 
Cc: Geert Uytterhoeven 
Cc: "Rafael J. Wysocki" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fbmem: fix fb_info->lock and mm->mmap_sem circular locking dependency

2009-04-01T15:59:29+00:00

Fix a circular locking dependency in the frame buffer console driver
pushing down the mutex fb_info->lock.

Circular locking dependecies occur calling the blocking
fb_notifier_call_chain() with fb_info->lock held.  Notifier callbacks can
try to acquire mm->mmap_sem, while fb_mmap() acquires the locks in the
reverse order mm->mmap_sem => fb_info->lock.

Tested-by: Andrey Borzenkov 
Signed-off-by: Andrea Righi 
Cc: Geert Uytterhoeven 
Cc: Krzysztof Helt 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fbdev: Kill Atari vblank cursor blinking

2009-01-12T19:56:43+00:00

Kill the last remaining vblank cursor blinking user

Signed-off-by: Geert Uytterhoeven

fbcon: Protect free_irq() by MACH_IS_ATARI check

2008-12-28T19:00:06+00:00

Add missing check for Atari in free_irq() call, which could cause problems on
multi-platform m68k kernels.

Reported-by: Brad Boyer 
Signed-off-by: Geert Uytterhoeven

fbcon: remove broken mac vbl handler

2008-12-28T19:00:06+00:00

Remove the Mac VBL interrupt code as it doesn't work properly and
doesn't bring any benefit when fixed. Also remove unused
DEFAULT_CURSOR_BLINK_RATE macro and irqres variable.

Signed-off-by: Finn Thain 
Signed-off-by: Geert Uytterhoeven

fbcon: fix workqueue shutdown

2008-12-10T16:01:53+00:00

Add a call to cancel_work_sync() in fbcon_exit() to cancel any pending
work in the fbcon workqueue.

The current implementation of fbcon_exit() sets the fbcon workqueue
function info->queue.func to NULL, but does not assure that there is no
work pending when it does so.  On occasion, depending on system timing,
there will still be pending work in the queue when fbcon_exit() is
called.  This results in a null pointer deference when run_workqueue()
tries to call the queue's work function.

Fixes errors on shutdown similar to these:

  Console: switching to colour dummy device 80x25
  Unable to handle kernel paging request for data at address 0x00000000

Signed-off-by: Geoff Levand 
Cc: Krzysztof Helt 
Cc: Geert Uytterhoeven 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds