[PATCH] md: make sure the new 'sb_size' is set properly device added without pre-existing superblock.
There are two ways to add devices to an md/raid array.
It can have superblock written to it, and then given to the md driver,
which will read the superblock (the new way)
or
md can be told (through SET_ARRAY_INFO) the shape of the array, and
the told about individual drives, and md will create the required
superblock (the old way).
The newly introduced sb_size was only set for drives being added the
new way, not the old ways. Oops :-(
Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
[PATCH] md: choose better default offset for bitmap.
On reflection, a better default location for hot-adding bitmaps with version-1
superblocks is immediately after the superblock. There might not be much room
there, but there is usually atleast 3k, and that is a good start.
Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
[PATCH] md: tidy up daemon stop/start code in md/bitmap.c
The bitmap code used to have two daemons, so there is some 'common' start/stop
code. But now there is only one, so the common code is just noise.
This patch tidies this up somewhat.
Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
mddev->bitmap gets clearred before the writeback daemon is stopped. So the
write_back daemon needs to be careful not to dereference the 'bitmap' if it is
NULL.
Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Switch MD to use the kthread infrastructure, to simplify the code and get rid
of tasklist_lock abuse in md_unregister_thread.
Also don't flush signals in md_thread, as the called thread will always do
that.
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
[PATCH] md: add write-intent-bitmap support to raid5
Most awkward part of this is delaying write requests until bitmap updates have
been flushed.
To achieve this, we have a sequence number (seq_flush) which is incremented
each time the raid5 is unplugged.
If the raid thread notices that this has changed, it flushes bitmap changes,
and assigned the value of seq_flush to seq_write.
When a write request arrives, it is given the number from seq_write, and that
write request may not complete until seq_flush is larger than the saved seq
number.
We have a new queue for storing stripes which are waiting for a bitmap flush
and an extra flag for stripes to record if the write was 'degraded' and so
should not clear the a bit in the bitmap.
Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
[PATCH] md: limit size of sb read/written to appropriate amount
version-1 superblocks are not (normally) 4K long, and can be of variable size.
Writing the full 4K can cause corruption (but only in non-default
configurations).
With this patch the super-block-flavour can choose a size to read, and set a
size to write based on what it finds.
Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
[PATCH] md: fix bitmap/read_sb_page so that it handles errors properly.
read_sb_page() assumed that if sync_page_io fails, the device would be marked
faultly. However it isn't. So in the face of error, read_sb_page would loop
forever.
Redo the logic so that this cannot happen.
Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
[PATCH] md: allow hot-adding devices to arrays with non-persistant superblocks.
It is possibly (and occasionally useful) to have a raid1 without persistent
superblocks. The code in add_new_disk for adding a device to such an array
always tries to read a superblock.
This will obviously fail.
So do the appropriate test and call md_import_device with
appropriate args.
Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
[PATCH] md: support md/linear array with components greater than 2 terabytes.
linear currently uses division by the size of the smallest componenet device
to find which device a request goes to. If that smallest device is larger
than 2 terabytes, then the division will not work on some systems.
So we introduce a pre-shift, and take care not to make the hash table too
large, much like the code in raid0.
Also get rid of conf->nr_zones, which is not needed.
Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
If a device is flagged 'WriteMostly' and the array has a bitmap, and the
bitmap superblock indicates that write_behind is allowed, then write_behind is
enabled for WriteMostly devices.
Write requests will be acknowledges as complete to the caller (via b_end_io)
when all non-WriteMostly devices have completed the write, but will not be
cleared from the bitmap until all devices complete.
This requires memory allocation to make a local copy of the data being
written. If there is insufficient memory, then we fall-back on normal write
semantics.
Signed-Off-By: Paul Clements <paul.clements@steeleye.com> Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
[PATCH] md: all hot-add and hot-remove of md intent logging bitmaps
Both file-bitmaps and superblock bitmaps are supported.
If you add a bitmap file on the array device, you lose.
This introduces a 'default_bitmap_offset' field in mddev, as the ioctl used
for adding a superblock bitmap doesn't have room for giving an offset. Later,
this value will be setable via sysfs.
Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
[PATCH] md: improve handling of bitmap initialisation.
When we find a 'stale' bitmap, possibly because it is new, we should just
assume every bit needs to be set, but rather base the setting of bits on the
current state of the array (degraded and recovery_cp).
Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
[PATCH] dm: fix rh_dec()/rh_inc() race in dm-raid1.c
Fix another bug in dm-raid1.c that the dirty region may stay in or be moved
to clean list and freed while in use.
It happens as follows:
CPU0 CPU1
------------------------------------------------------------------------------
rh_dec()
if (atomic_dec_and_test(pending))
<the region is still marked dirty>
rh_inc()
if the region is clean
mark the region dirty
and remove from clean list
mark the region clean
and move to clean list
atomic_inc(pending)
At this stage, the region is in clean list and will be mistakenly reclaimed
by rh_update_states() later.
[PATCH] md: fix minor error in raid10 read-balancing calculation.
'this_sector' is a virtual (array) address while 'head_position' is a physical
(device) address, so substraction doesn't make any sense. devs[slot].addr
should be used instead of this_sector.
However, this patch doesn't make much practical different to the read
balancing due to the effects of later code.
Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Don't just irritate all other kernel developers. Fix the users first,
then you can re-introduce the must-check infrastructure to avoid new
cases creeping in.
Daniel Ritz [Thu, 8 Sep 2005 22:57:14 +0000 (00:57 +0200)]
[PATCH] Update PCI IOMEM allocation start
This fixes the problem with "Averatec 6240 pcmcia_socket0: unable to
apply power", which was due to the CardBus IOMEM register region being
allocated at an address that was actually inside the RAM window that had
been reserved for video frame-buffers in an UMA setup.
The BIOS _should_ have marked that region reserved in the e820 memory
descriptor tables, but did not.
It is fixed by rounding up the default starting address of PCI memory
allocations, so that we leave a bigger gap after the final known memory
location. The amount of rounding depends on how big the unused memory
gap is that we can allocate IOMEM from.
Clean up timer initialization by introducing DEFINE_TIMER a'la
DEFINE_SPINLOCK. Build and boot-tested on x86. A similar patch has been
been in the -RT tree for some time.
[PATCH] FUSE: don't allow restarting of system calls
This patch removes ability to interrupt and restart operations while there
hasn't been any side-effect.
The reason: applications. There are some apps it seems that generate
signals at a fast rate. This means, that if the operation cannot make
enough progress between two signals, it will be restarted for ever. This
bug actually manifested itself with 'krusader' trying to open a file for
writing under sshfs. Thanks to Eduard Czimbalmos for the report.
The problem can be solved just by making open() uninterruptible, because in
this case it was the truncate operation that slowed down the progress. But
it's better to solve this by simply not allowing interrupts at all (except
SIGKILL), because applications don't expect file operations to be
interruptible anyway. As an added bonus the code is simplified somewhat.
Don't change mtime/ctime/atime to local time on read/write. Rather invalidate
file attributes, so next stat() will force a GETATTR call. Bug reported by
Ben Grimm.
Make data caching behavior selectable on a per-open basis instead of
per-mount. Compatibility for the old mount options 'kernel_cache' and
'direct_io' is retained in the userspace library (version 2.4.0-pre1 or
later).
[PATCH] fuse: transfer readdir data through device
This patch removes a long lasting "hack" in FUSE, which used a separate
channel (a file descriptor refering to a disk-file) to transfer directory
contents from userspace to the kernel.
The patch adds three new operations (OPENDIR, READDIR, RELEASEDIR), which
have semantics and implementation exactly maching the respective file
operations (OPEN, READ, RELEASE).
This simplifies the directory reading code. Also disk space is not
necessary, which can be important in embedded systems.
This patch adds support for the "direct_io" mount option of FUSE.
When this mount option is specified, the page cache is bypassed for
read and write operations. This is useful for example, if the
filesystem doesn't know the size of files before reading them, or when
any kind of caching is harmful.
[PATCH] FUSE: tighten check for processes allowed access
This patch tightens the check for allowing processes to access non-privileged
mounts. The rational is that the filesystem implementation can control the
behavior or get otherwise unavailable information of the filesystem user. If
the filesystem user process has the same uid, gid, and is not suid or sgid
application, then access is safe. Otherwise access is not allowed unless the
"allow_other" mount option is given (for which policy is controlled by the
userspace mount utility).
Thanks to everyone linux-fsdevel, especially Martin Mares who helped uncover
problems with the previous approach.
With the help of the readpages() operation multiple reads are bundled
together and sent as a single request to userspace. This can improve
reading performace.
This patch adds miscellaneous mount options to the FUSE filesystem.
The following mount options are added:
o default_permissions: check permissions with generic_permission()
o allow_other: allow other users to access files
o allow_root: allow root to access files
o kernel_cache: don't invalidate page cache on open
The most important difference between orinary filesystems and FUSE is
the fact, that the filesystem data/metadata is provided by a userspace
process run with the privileges of the mount "owner" instead of the
kernel, or some remote entity usually running with elevated
privileges.
The security implication of this is that a non-privileged user must
not be able to use this capability to compromise the system. Obvious
requirements arising from this are:
- mount owner should not be able to get elevated privileges with the
help of the mounted filesystem
- mount owner should not be able to induce undesired behavior in
other users' or the super user's processes
- mount owner should not get illegitimate access to information from
other users' and the super user's processes
These are currently ensured with the following constraints:
1) mount is only allowed to directory or file which the mount owner
can modify without limitation (write access + no sticky bit for
directories)
2) nosuid,nodev mount options are forced
3) any process running with fsuid different from the owner is denied
all access to the filesystem
1) and 2) are ensured by the "fusermount" mount utility which is a
setuid root application doing the actual mount operation.
3) is ensured by a check in the permission() method in kernel
I started thinking about doing 3) in a different way because Christoph
H. made a big deal out of it, saying that FUSE is unacceptable into
mainline in this form.
The suggested use of private namespaces would be OK, but in their
current form have many limitations that make their use impractical (as
discussed in this thread).
Suggested improvements that would address these limitations:
- implement shared subtrees
- allow a process to join an existing namespace (make namespaces
first-class objects)
- implement the namespace creation/joining in a PAM module
With all that in place the check of owner against current->fsuid may
be removed from the FUSE kernel module, without compromising the
security requirements.
Suid programs still interesting questions, since they get access even
to the private namespace causing some information leak (exact
order/timing of filesystem operations performed), giving some
ptrace-like capabilities to unprivileged users. BTW this problem is
not strictly limited to the namespace approach, since suid programs
setting fsuid and accessing users' files will succeed with the current
approach too.
This patch brings the now out-of-date Documentation/filesystems/vfs.txt
back to life. Thanks to Carsten Otte, Trond Myklebust, and Anton
Altaparmakov for their help on updating this documentation.
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Pekka Enberg [Fri, 9 Sep 2005 20:10:16 +0000 (13:10 -0700)]
[PATCH] update kfree, vfree, and vunmap kerneldoc
This patch clarifies NULL handling of kfree() and vfree(). I addition,
wording of calling context restriction for vfree() and vunmap() are changed
from "may not" to "must not."
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Update the hacking guide, before CONFIG_PREEMPT_RT goes in and it needs
rewriting again.
Changes include modernization of quotes, removal of most references to
bottom halves (some mention required because we still use bh in places to
mean softirq).
It would be nice to have a discussion of sparse and various annotations.
Please send patches straight to akpm.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (authored) Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This set of two patches add support for the framebuffer of the Samsung S3C2410
ARM SoC. This driver was started about one year ago and is now used on iPAQ
h1930/h1940, Acer n30 and probably other s3c2410-based machines I'm not aware
of. I've also heard yesterday that it's working also on iPAQ rx3715/rx3115
(s3c2440-based machines).
Signed-Off-By: Arnaud Patard <arnaud.patard@rtp-net.org> Signed-off-by: Antonino Daplas <adaplas@pol.net> Signed-off-by: Ben Dooks <ben@trinity.fluff.org> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add ddc/i2c support for i810fb. This will allow the driver to get display
information, especially for monitors with fickle timings. The i2c support
depends on CONFIG_FB_I810_GTF.
Changed __init* to __devinit*
Signed-off-by: Antonino Daplas <adaplas@pol.net> Signed-off-by: Alexander Nyberg <alexn@telia.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
[PATCH] fbcon: Break up bit_putcs into its component functions
The function bit_putcs() in drivers/video/console/bitblit.c is becoming large.
Break it up into its component functions (bit_putcs_unaligned and
bit_putcs_aligned).
Incorporated fb_pad_aligned_buffer() optimization by Roman Zippel.
Richard Purdie [Fri, 9 Sep 2005 20:10:03 +0000 (13:10 -0700)]
[PATCH] pxafb: Add hsync time reporting hook
To solve touchscreen interference problems devices like the Sharp Zaurus
SL-C3000 need to know the length of the horitzontal sync pulses. This patch
adds a hook to pxafb so the touchscreen driver can function correctly.
Signed-Off-By: Richard Purdie <rpurdie@rpsys.net> Signed-off-by: Antonino Daplas <adaplas@pol.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
[PATCH] nvidiafb: Fixed mirrored characters in big endian machines
nvidiafb_imageblit converts the bitdata stream from big_endian to little
endian. This produces mirrored characters when machine is big_endian. Do not
endian convert on big endian machines.
[PATCH] nvidiafb: Use CVT to get mode for digital displays
If no EDID block is probed, if the display is digital and if no mode option is
specified by the user, get the timings by CVT instead of using the global mode
database.
[PATCH] fbdev: Add VESA Coordinated Video Timings (CVT) support
The Coordinated Video Timings (CVT) is the latest standard approved by VESA
concerning video timings generation. It addresses the limitation of GTF which
is designed mainly for CRT displays. CRT's have a high blanking requirement
(as much as 25% of the horizontal frame length) which artificially increases
the pixelclock. Digital displays, on the other hand, needs to conserve the
pixelclock as much as possible. The GTF also does not take into account the
different aspect ratios in its calculation.
The new function added is fb_find_mode_cvt(). It is called by fb_find_mode()
if it recognizes a mode option string formatted for CVT. The format is:
The 'M' tells the function to calculate using CVT. On it's own, it will
compute a timing for CRT displays at 60Hz. If the 'R' is specified, 'reduced
blanking' computation will be used, best for flatpanels. The 'i' and the 'm'
is for 'interlaced mode' and 'with margins' respectively.
To determine if CVT was used, check for dmesg for something like this:
where: pix - product of xres and yres, in MB
M - is a CVT mode
n - the aspect ratio (3 - 4:3; 4 - 5:4; 9 - 16:9, 15:9; A - 16:10)
-R - reduced blanking
Paul Mackerras [Mon, 5 Sep 2005 23:31:03 +0000 (09:31 +1000)]
[PATCH] PCI: Small rearrangement of PCI probing code
This patch makes some small rearrangements of the PCI probing code in
order to make it possible for arch code to set up the PCI tree
without needing to duplicate code from the PCI layer unnecessarily.
PPC64 will use this to set up the PCI tree from the Open Firmware
device tree, which we need to do on logically-partitioned pSeries
systems.
Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Rajesh Shah [Wed, 17 Aug 2005 00:32:04 +0000 (17:32 -0700)]
[PATCH] PCI: Fix PCI bus mastering enable problem in pciehp
Martin Franc reported that the pciehp driver was not enabling bus
master capability on his hot-plugged card. pciehprm_enable_card()
was updating the PCI command register only if _HPP indicated a
value for SERR or PERR that was different from the current setting.
I don't have hardware that reproduces this problem, but Martin
reports that this patch fixes the problem for him.
Signed-off-by: Rajesh Shah <rajesh.shah@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
From rzarev@its.caltech.edu Tue Sep 6 18:29:50 2005
Date: Tue, 6 Sep 2005 13:39:32 -0700 (PDT)
From: Rumen Ivanov Zarev <rzarev@its.caltech.edu>
Message-Id: <200509062039.j86KdWMr014934@inky.its.caltech.edu>
To: gregkh@suse.de
Subject: PCI: Unhide SMBus on Compaq Evo N620c Cc: linux-kernel@vger.kernel.org
Trivial patch against 2.6.13 to unhide SMBus on Compaq Evo N620c laptop using
Intel 82855PM chipset.
Daniel Burcaw [Fri, 9 Sep 2005 20:04:59 +0000 (13:04 -0700)]
[PATCH] radeonfb: Only request resources we need
This patch changes radeon to request only resources 0 and 2 instead of all
3. This works around problems with some setups where BAR 1 (IO BAR) has
not been assigned by the firmware since it's not used on the machine and
the kernel fails to assign something to it due to the card being between a
P2P bridge that was configured without an IO range at all.
This typically fixes radeonfb on some Apple Xserve G5 machines
Signed-off-by: Daniel Burcaw <dburcaw@terrasoftsolutions.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
[PATCH] framebuffer: bit_putcs() optimization for 8x* fonts
This trivial patch gives a performance boost to the framebuffer console
Constructing the bitmaps that are given to the bitblit functions of the
framebuffer drivers is time consuming. Here we avoide a call to the slow
fb_pad_aligned_buffer(). The patch replaces that call with a simple but
much more efficient bytewise copy.
The kernel spends a significant time at this place if you use 8x* fonts.
Every pixel displayed on your screen is prepared here.
Some benchmark results:
Displaying a file of 2000 lines with 160 characters each takes 889 ms
system time using cyblafb on my system (I´m using a 1280x1024 video mode,
resulting in a 160x64 character console)
Displaying the same file with the enclosed patch applied to 2.6.13 only
takes 760 ms system time, saving 129 ms or 14.5%.
Font widths other than 8 are not affected.
The advantage and correctness of this patch should be obvious.
[PATCH] framebuffer: new driver for cyberblade/i1 graphics core
This is a framebuffer driver for the Cyberblade/i1 graphics core.
Currently tridenfb claims to support the cyberblade/i1 graphics core. This
is of very limited truth. Even vesafb is faster and provides more working
modes and a much better quality of the video signal. There is a great
number of bugs in tridentfb ... but most often it is impossible to decide
if these bugs are real bugs or if fixing them for the cyberblade/i1 core
would break support for one of the other supported chips.
Tridentfb seems to be unmaintained,and documentation for most of the
supported chips is not available. So "fixing" cyberblade/i1 support inside
of tridentfb was not an option, it would have caused numerous
if(CYBERBLADEi1) else ... cases and would have rendered the code to be
almost unmaintainable.
A first version of this driver was published on 2005-07-31. A fix for a
bug reported by Jochen Hein was integrated as well as some changes
requested by Antonino A. Daplas.
A message has been added to tridentfb to inform current users of tridentfb
to switch to cyblafb if the cyberblade/i1 graphics core is detected.
This patch is one logical change, but because of the included documentation
it is bigger than 70kb. Therefore it is not sent to lkml and
linux-fbdev-devel,
Ian Romanick [Fri, 9 Sep 2005 20:04:42 +0000 (13:04 -0700)]
[PATCH] matroxfb: read MGA PInS data on PowerPC
This updates the matroxfb code so that it can find the PInS data embedded
in the BIOS on PowerPC cards. The process for finding the data is
different on OpenFirmware cards than on x86 cards, and the code for doing
so was missing.
After patching, building, installing, and booting a kernel, you should grep
for "PInS" in /var/log/messages. You should see two messages in the log:
PInS data found at offset XXXXX
PInS memtype = X
On the GXT135p card I get "31168" and "5". The first value is irrelevant,
but it's presence lets me know that the PInS data was actually found. On a
GXT130p, the second value should be 3. Since I don't have access to that
hardware, if someone can verify that, I will submit a follow-on patch that
rips out all the memtype parameter stuff.
Signed-off-by: Ian Romanick <idr@us.ibm.com> Signed-off-by: Petr Vandrovec <vandrove@vc.cvut.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
On a vc resize, the contents of the old screen buffer are transferred to the
new screenbuffer. If the new screenbuffer is smaller than the old one, only
the contents from the bottom are copied to new. If the contents of the old
buffer are located at the top, then the contents will not be copied to the new
buffer resulting in a blank screen.
This bug will happen only if the vc in question is not in the foreground.
Doing an fbset -a or con2fbmap will trigger this bug.
To fix this problem, base the start of the copy from the location of the
current cursor. If the cursor is near the top of the buffer, copy the
contents at the top, and if the cursor is near the bottom of the buffer, then
copy the contents at the bottom. In the unlikely case where the new row size
is greater than 2x smaller than the old one, and the cursor is in the middle,
copy 1/2 screenful from the top and bottom of the cursor position.
[PATCH] fbcon: Saner 16-color to 4-color conversion
Currently, the default linux 16-colors are converted to 4-colors by simply
dividing the values by 4. However, this is not necessarily correct since the
first 4 colors are converted to black, rendering them invisible.
So, for black, no conversion; for light colors, convert to gray, for normal
text color, no conversion, and for bright colors, convert to intense white.
[PATCH] fbdev: Fix greater than 1 bit monochrome color handling
Currently, fbcon assumes that the visual FB_VISUAL_MONO* is always 1 bit.
According to Geert, there are old hardware where it's possible to have
monochrome at 8-bit, but has only 2 colors, black - 0x00 and white - 0xff.
Fix color handlers (fb_get_color_depth, and get_color) for this special case.