linux-stable.git/drivers/video/fbdev/udlfb.c, branch linux-3.16.y

udlfb: set line_length in dlfb_ops_set_par

2018-12-16T22:08:23+00:00

commit 0ac319b7af1bb24a33365d0ec82a2f56a59b2a78 upstream.

Set the variable "line_length" in the function dlfb_ops_set_par. Without
this, we get garbage if we select different videomode with fbset.

Signed-off-by: Mikulas Patocka 
Signed-off-by: Bartlomiej Zolnierkiewicz 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

udlfb: handle allocation failure

2018-12-16T22:08:23+00:00

commit 080fb5240bdcabed7387b814139c3ea172d59fc5 upstream.

Allocations larger than PAGE_ALLOC_COSTLY_ORDER are unreliable and they
may fail anytime. This patch fixes the udlfb driver so that when a large
alloactions fails, it tries to do multiple smaller allocations.

Signed-off-by: Mikulas Patocka 
Signed-off-by: Bartlomiej Zolnierkiewicz 
[bwh: Backported to 3.16:
 - Pointers to struct dlfb_data are named "dev" rather than "dlfb"
 - Adjust context]
Signed-off-by: Ben Hutchings

udlfb: make a local copy of fb_ops

2018-12-16T22:08:22+00:00

commit 2c29cfc3eaf11779176bf41475cfca49bccba11c upstream.

The defio subsystem overwrites the method fb_osp->mmap. That method is
stored in module's static data - and that means that if we have multiple
diplaylink adapters, they will over write each other's method.

In order to avoid interference between multiple adapters, we copy the
fb_ops structure to a device-local memory.

Signed-off-by: Mikulas Patocka 
Signed-off-by: Bartlomiej Zolnierkiewicz 
[bwh: Backported to 3.16: Pointer to struct dlfb_data is named "dev" rather
 than "dlfb"]
Signed-off-by: Ben Hutchings

udlfb: don't switch if we are switching to the same videomode

2018-12-16T22:08:22+00:00

commit 564f1807379298dfdb12ed0d5b25fcb89c238527 upstream.

The udlfb driver reprograms the hardware everytime the user switches the
console, that makes quite unusable when working on the console.

This patch makes the driver remember the videomode we are in and avoid
reprogramming the hardware if we switch to the same videomode.

We mask the "activate" field and the "FB_VMODE_SMOOTH_XPAN" flag when
comparing the videomode, because they cause spurious switches when
switching to and from the Xserver.

Signed-off-by: Mikulas Patocka 
Signed-off-by: Bartlomiej Zolnierkiewicz 
[bwh: Backported to 3.16: Pointer to struct dlfb_data is named "dev" rather
 than "dlfb"]
Signed-off-by: Ben Hutchings

udlfb: fix display corruption of the last line

2018-12-16T22:08:21+00:00

commit 4e705e17ce3409a1f492cfd5dadcf6a4f6075842 upstream.

The displaylink hardware has such a peculiarity that it doesn't render a
command until next command is received. This produces occasional
corruption, such as when setting 22x11 font on the console, only the first
line of the cursor will be blinking if the cursor is located at some
specific columns.

When we end up with a repeating pixel, the driver has a bug that it leaves
one uninitialized byte after the command (and this byte is enough to flush
the command and render it - thus it fixes the screen corruption), however
whe we end up with a non-repeating pixel, there is no byte appended and
this results in temporary screen corruption.

This patch fixes the screen corruption by always appending a byte 0xAF at
the end of URB. It also removes the uninitialized byte.

Signed-off-by: Mikulas Patocka 
Signed-off-by: Bartlomiej Zolnierkiewicz 
[bwh: Backported to 3.16:
 - Pointers to struct dlfb_data are named "dev" rather than "dlfb"
 - s/BPP/bpp/
Signed-off-by: Ben Hutchings

udlfb: fix semaphore value leak

2018-12-16T22:08:21+00:00

commit 9d0aa601e4cd9c0892f90d36e8488d79b72f4073 upstream.

I observed that the performance of the udl fb driver degrades over time.
On a freshly booted machine, it takes 6 seconds to do "ls -la /usr/bin";
after some time of use, the same operation takes 14 seconds.

The reason is that the value of "limit_sem" decays over time.

The udl driver uses a semaphore "limit_set" to specify how many free urbs
are there on dlfb->urbs.list. If the count is zero, the "down" operation
will sleep until some urbs are added to the freelist.

In order to avoid some hypothetical deadlock, the driver will not call
"up" immediately, but it will offload it to a workqueue. The problem is
that if we call "schedule_delayed_work" on the same work item multiple
times, the work item may only be executed once.

This is happening:
* some urb completes
* dlfb_urb_completion adds it to the free list
* dlfb_urb_completion calls schedule_delayed_work to schedule the function
  dlfb_release_urb_work to increase the semaphore count
* as the urb is on the free list, some other task grabs it and submits it
* the submitted urb completes, dlfb_urb_completion is called again
* dlfb_urb_completion calls schedule_delayed_work, but the work is already
  scheduled, so it does nothing
* finally, dlfb_release_urb_work is called, it increases the semaphore
  count by 1, although it should increase it by 2

So, the semaphore count is decreasing over time, and this causes gradual
performance degradation.

Note that in the current kernel, the "up" function may be called from
interrupt and it may race with the "down" function called by another
thread, so we don't have to offload the call of "up" to a workqueue at
all. This patch removes the workqueue code. The patch also changes
"down_interruptible" to "down" in dlfb_free_urb_list, so that we will
clean up the driver properly even if a signal arrives.

With this patch, the performance of udlfb no longer degrades.

Signed-off-by: Mikulas Patocka 
[b.zolnierkie: fix immediatelly -> immediately typo]
Signed-off-by: Bartlomiej Zolnierkiewicz 
[bwh: Backported to 3.16: Pointers to struct dlfb_data are named "dev" rather
 than "dlfb"]
Signed-off-by: Ben Hutchings

video: udlfb: Fix unaligned access

2018-12-16T22:08:21+00:00

commit 115e77597efcc94cb1f6cbb7df5cf7ce8feb8632 upstream.

Driver generates lots of alignment trap exceptions on ARM.
Fix that by replacing typecasting of odd addresses with
byte shifting and remove uneccessary typecasting.

Signed-off-by: Ladislav Michl 
Cc: Bernie Thompson 
Signed-off-by: Bartlomiej Zolnierkiewicz 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

video: udlfb: Remove noisy warnings

2018-12-16T22:08:20+00:00

commit de4b74bda8e87a4ed45ebc2c26cc3e2eaae38429 upstream.

These warnings comes from times of driver development and do
not carry any usefull debugging information.

Signed-off-by: Ladislav Michl 
Cc: Bernie Thompson 
Signed-off-by: Bartlomiej Zolnierkiewicz 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

video: udlfb: Fix read EDID timeout

2018-02-13T18:42:20+00:00

commit c98769475575c8a585f5b3952f4b5f90266f699b upstream.

While usb_control_msg function expects timeout in miliseconds, a value
of HZ is used. Replace it with USB_CTRL_GET_TIMEOUT and also fix error
message which looks like:
udlfb: Read EDID byte 78 failed err ffffff92
as error is either negative errno or number of bytes transferred use %d
format specifier.

Returned EDID is in second byte, so return error when less than two bytes
are received.

Fixes: 18dffdf8913a ("staging: udlfb: enhance EDID and mode handling support")
Signed-off-by: Ladislav Michl 
Cc: Bernie Thompson 
Signed-off-by: Bartlomiej Zolnierkiewicz 
Signed-off-by: Ben Hutchings

video: move fbdev to drivers/video/fbdev

2014-04-17T05:10:19+00:00

The drivers/video directory is a mess. It contains generic video related
files, directories for backlight, console, linux logo, lots of fbdev
device drivers, fbdev framework files.

Make some order into the chaos by creating drivers/video/fbdev
directory, and move all fbdev related files there.

No functionality is changed, although I guess it is possible that some
subtle Makefile build order related issue could be created by this
patch.

Signed-off-by: Tomi Valkeinen 
Acked-by: Laurent Pinchart 
Acked-by: Geert Uytterhoeven 
Acked-by: Rob Clark 
Acked-by: Jingoo Han 
Acked-by: Daniel Vetter