Enables page fault based detection of mmap writes to the framebuffer,
which allows standard fbdev apps (like the generic fbdev xorg driver)
to work on DisplayLink devices.

Not all bugs are shaken out of the fb_defio path of udlfb, but it's
tantalizingly close, so this seems a good time to enable by default.

Alternatively, option can be disabled when running with an xorg driver
that can more directly communicate damaged regions of the framebuffer
via IOCTL. This is a simpler, higher perf option, when available.
Signed-off-by: NBernie Thompson <bernie@plugable.com>
Signed-off-by: NFlorian Tobias Schandinat <FlorianSchandinat@gmx.de>

By default, udlfb allocates a 2nd buffer to shadow what's across
the bus on the USB device.  It can operate without this shadow,
but then it cannot tell which pixels have changed, and must send all.

Saves host memory, but worsens the USB 2.0 bus bottleneck.

This option allows users in very low memory situations (e.g.
bifferboard) to optionally turn off this shadow framebuffer.
Signed-off-by: NStuart Hopkins <stuart@linux-depot.com>
Signed-off-by: NBernie Thompson <bernie@plugable.com>
Signed-off-by: NFlorian Tobias Schandinat <FlorianSchandinat@gmx.de>

Add __user casting, a missing copy_from_user, and proper boolean
Signed-off-by: NDr. David Alan Gilbert <linux@treblig.org>
Signed-off-by: NBernie Thompson <bernie@plugable.com>
Signed-off-by: NFlorian Tobias Schandinat <FlorianSchandinat@gmx.de>

For at least one DisplayLink device, the vendor-specific information can
be found in the config descriptor instead of as a separate, device-level
descriptor.  This patch searches the current interface (of the current
config descriptor) for the DL vendor-specific descriptor.
Signed-off-by: NAndrew Kephart <akephart@akephart.org>
Signed-off-by: NBernie Thompson <bernie@plugable.com>
Signed-off-by: NFlorian Tobias Schandinat <FlorianSchandinat@gmx.de>

Fixes earlier problems where monitor would not return from blank

Test with any DisplayLink-based USB 2.0 graphics adapter
sudo nano /sys/class/graphics/fb?/blank
and write out single digit FB_BLANK_* code from include/linux/fb.h

Supports on (0), blank (1), suspend (2,3), powerdown (4)
Signed-off-by: NBernie Thompson <bernie@plugable.com>
Signed-off-by: NFlorian Tobias Schandinat <FlorianSchandinat@gmx.de>

The situation in which the problem occurred was with a Plugable UGA-2K-A
connected to a Samsung EX2220X display. The driver indicates that
1920x1080 is a valid mode (the first mode available, in fact), but
proceeds to set the framebuffer size to 1600x1200.

The patch corrects what seems to be a logic error, regarding unsetting
the FB_MISC_1ST_DETAIL flag, if the first (top/best) mode is invalid.
The existing code unset the flag if ANY mode was invalid.
Signed-off-by: NWilliam Katsak <william.katsak@alcatel-lucent.com>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Many stupid corrections of duplicated includes based on the output of
scripts/checkincludes.pl.
Signed-off-by: NVitaliy Ivanov <vitalivanov@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Commit e66eed65 ("list: remove prefetching from
regular list iterators") removed the include of prefetch.h from list.h,
so we need to include it explicitly, now.

fixes this build error on powerpc:

drivers/video/udlfb.c: In function 'dlfb_compress_hline':
drivers/video/udlfb.c:421: error: implicit declaration of function 'prefetch_range'
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

build warning:

...
drivers/video/udlfb.c:1590: warning: ignoring return value of ‘device_create_file’, declared with attribute warn_unused_result
drivers/video/udlfb.c:1592: warning: ignoring return value of ‘device_create_bin_file’, declared with attribute warn_unused_result
...

So add two checks to get rid of 'em.
Signed-off-by: NLiu Yuan <tailai.ly@taobao.com>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Commit e66eed65 ("list: remove prefetching from regular list
iterators") removed the include of prefetch.h from list.h, which
uncovered several cases that had apparently relied on that rather
obscure header file dependency.

So this fixes things up a bit, using

   grep -L linux/prefetch.h $(git grep -l '[^a-z_]prefetchw*(' -- '*.[ch]')
   grep -L 'prefetchw*(' $(git grep -l 'linux/prefetch.h' -- '*.[ch]')

to guide us in finding files that either need <linux/prefetch.h>
inclusion, or have it despite not needing it.

There are more of them around (mostly network drivers), but this gets
many core ones.
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>

This kills off all of the dl_xxx() printk wrappers and simply stubs in a
pr_fmt() definition to accomplish the same thing.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

The edid length is fixed, so use the standard definition consistently.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

udlfb selects all of the options it presently ifdef conditionalizes, so
none of the statements have any effect outside of aggravating eye strain.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

udlfb has undergone a fair bit of cleanup recently and is effectively at
the point where it can be liberated from staging purgatory and promoted
to a real driver.

The outstanding cleanups are all minor, with some of them dependent on
drivers/video headers, so these will be done incrementally from udlfb's
new home.
Requested-by: NBernie Thompson <bernie@plugable.com>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Signed-off-by: NJoe Perches <joe@perches.com>
Cc: Bernie Thompson <bernie@plugable.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Fix warnings detected by tools
Signed-off-by: NBernie Thompson <bernie@plugable.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Fix fb_defio bug in udlfb for multiple framebuffers

Previously when using fb_defio with multiple DisplayLink attached displays
udlfb incorrectly used a shared datastructure where it needed to have
one per fb_info struct. This was completely broken and caused all kinds of
problems, including rendering to one framebuffer affecting others.
Signed-off-by: NBernie Thompson <bernie@plugable.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Add module options for console and fb_defio

Convert fb_defio on/off switch to module option and add console option.

>From the command line, pass options to modprobe
modprobe udlfb defio=1 console=1

Or for permanent option, create file like /etc/modprobe.d/options with text
options udlfb defio=1 console=1

Accepted options:

fb_defio	Make use of the fb_defio (CONFIG_FB_DEFERRED_IO) kernel
		module to track changed areas of the framebuffer by page faults.
        	Standard fbdev applications that use mmap but that do not
		report damage, may be able to work with this enabled.
		Disabled by default because of overhead and other issues.

console		Allow fbcon to attach to udlfb provided framebuffers. This
		is disabled by default because fbcon will aggressively consume
		the first framebuffer it finds, which isn't usually what the
		user wants in the case of USB displays.
Signed-off-by: NBernie Thompson <bernie@plugable.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Support writing default/backup edid via /sys/class/graphics/fb?/edid

Writing a backup edid blob to the 'edid' file will cause udlfb to
attempt to re-read the edid from hardware.
If we still don't have a good edid, it will use the backup edid instead.
The intent is to 1) enable user-supplied edid
2) enable udev rules to backup the last known good edid
for a device, and then provide that edid as a backup for all future starts
Signed-off-by: NBernie Thompson <bernie@plugable.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Fix big endian rendering bug (affects PowerPC)

Thanks to Christian Melki at Ericsson for finding and suggesting patch.
Signed-off-by: NBernie Thompson <bernie@plugable.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Enhance EDID and mode table handling

* Adds support for lower-end DL chips on higher-end monitors
* Adds support for using fbdev standard EDID parsing and handling
* Adds support for more dynamic reallocation of framebuffer, based on new EDID

Queries EDID from hardware with several retries then
queries DisplayLink chip for max pixel area via vendor descriptor.
Uses existing fbdev mode handling service funcations to build mode list
of common modes between adapter and monitor.
This enables lower-end chips (e.g. DL-125) to successfully pick a compatible
mode on higher end monitors (e.g. whose default mode is over 1280x1024).
Reallocate framebuffer if necessary in response to new max mode.
Signed-off-by: NBernie Thompson <bernie@plugable.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Revamp reference handling and synchronization for unload/shutdown

Udlfb is a "virtual" framebuffer device that really exists on
two separate stacks: at the bottom of the framebuffer interface,
and on top of USB.  During unload, there's no guarantee which
one will tear down first. So reference counting must be solid
to handle all possibilities and not access anything once its gone.
Signed-off-by: NBernie Thompson <bernie@plugable.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Remove metrics_misc sysfs attribute

Previously returned multiple values, which goes against sysfs guidelines.
Had been used for debugging to figure out which of the multiple
fbdev interfaces an app was using, but log file messages are sufficient.
Signed-off-by: NBernie Thompson <bernie@plugable.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Add ability to power off monitor with standard blanking interface

Used by X servers and others to manage power of dislpay
Signed-off-by: NBernie Thompson <bernie@plugable.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Restore fbdev character read and write support

Enables access to the framebuffer from simple reads and writes
to /dev/fb0 (or fb1, ...). Low performance, because of extra copy
and because udlfb must scan every pixel for changes. But very
useful for testing and simple image display, etc.
Signed-off-by: NBernie Thompson <bernie@plugable.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This allows bin_attr->read,write,mmap callbacks to check file specific data
(such as inode owner) as part of any privilege validation.
Signed-off-by: NChris Wright <chrisw@sous-sol.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This renames the functions usb_buffer_alloc and usb_buffer_free to the correct
ones for the drivers in the staging tree.

Cc: Daniel Mack <daniel@caiaq.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This is a patch to the file udlfb.c that fixes a missing KERN_INFO and
removes one whitespace before a newline.
Signed-off-by: NSoeren Moeller <soerenmoeller2001@gmail.com>
Cc: Bernie Thompson <bernie@plugable.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This cleans up udlfb a tiny bit.
Signed-off-by: NPavel Machek <pavel@ucw.cz>
Cc: Bernie Thompson <bernie@plugable.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: NTejun Heo <tj@kernel.org>
Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

Remove last remaining printk and clarify comments
Signed-off-by: NBernie Thompson <bernie@plugable.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Specify Kconfig dependencies, and include warnings for building as a module

udlfb is dependent on FB_DEFERRED_IO, FB_SYS_*, and FB_MODE_HELPERS

Because many kernels do not include defio (which cannot be built
as a module), yet users want to be able to build udlfb as a module later,
udlfb has ifdefs and these dependency warnings to help udlfb build with or
without certain dependencies, but also print warnings for any lost function.

Even though this kind of flexibility isn't common, we've gotten feedback
from a significant portion of users that they were frustrated without it.
Signed-off-by: NBernie Thompson <bernie@plugable.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Add support for fbdev mmap clients who don't send damage ioctls

Because DisplayLink devices are out on the other end of usb, their
"framebuffer" is just normal system memory. So memory mapped writes
don't automatically trigger anything. So up to this point, standard
fbdev clients who rely on mmap() will get an unchanging screen.

This patch makes udlfb a client of Jaya Kumar's defio framework - which sets
up page fault triggers, and those faults are accumulated and sent to udlfb
on a defferred basis, to process as damage notifications for the framebuffer.

Because this involves more overhead than a notification directly from
the application (e.g. just passing on X DAMAGE extension notifications),
a sysfs attribute is provided by udlfb to control defio support.

/sys/class/graphics/fb*/use_defio - writing a "0" to this file before
calling mmap() causes defio to not be initialized - instead udlfb
will rely on getting damage notifications directly through the damage ioctl.

There are unsolved rendering problems with defio (horizontal dead regions
on framebuffer, that accumulate over time) which still needs a fix.
Signed-off-by: NBernie Thompson <bernie@plugable.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Rework rendering for improved performance

Approx 10-20% gain avg across several "benchmarks": x11perf, gtkperf, glxgears
Moves from a single pre-alloc'd urb protected by a long-held mutex
To a list of (4) pre-alloc'd urbs which can be dispatched asynchonously

Improved rendering algorithm to hardware with lower CPU consumption,
fewer system memory accesses, and slightly higher compression.

Better scalability to multiple processors, especially with
multiple framebuffers active.
Signed-off-by: NBernie Thompson <bernie@plugable.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Rework probe to use refcounts and std functions

Because the different parts of the driver (usb, fbdev) tear down
in different orders, the driver previously could crash accessing
data that had already been freed.  Refcounting system used to handle.

Reworked probe to make use of refcounts, set mode using std fbops,
and set up sysfs and pre-allocated urbs.
Signed-off-by: NBernie Thompson <bernie@plugable.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Add sysfs controls for edid and performance metrics

There are 8 new files exposed in /sys/class/graphics/fb*

edid - returns 128 byte edid blog, suitable for parsing with parse-edid
metrics_bytes_identical
metrics_bytes_rendered
metrics_bytes_sent
metrics_cpu_kcycles_used
metrics_misc
and metrics_reset, which resets all perf metrics to zero

The 6 perf metrics are of type atomic_t.
So these metrics return precise results for short benchmarks, but
any test approx a minute or longer runtime may roll over.
Signed-off-by: NBernie Thompson <bernie@plugable.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Move to more consistent naming scheme

All udlfb functions start with udlfb_
All functions for udlfb's fbdev interface start with udlfb_ops_
All functinos for udlfb's usb interface start with udlfb_usb_
Signed-off-by: NBernie Thompson <bernie@plugable.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Add functions to pre-allocate and free usb bulk urbs for core render path.

Udlfb currently allocates a single urb, guarded by a mutex, that is a key
bottleneck. Because udlfb sends so much data, preallocation is most efficient.

Functions will be used by new rendering functions in later patches.
Signed-off-by: NBernie Thompson <bernie@plugable.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>