When booting in a direct color mode, the penguin has dirty feet, i.e.,
some pixels have the wrong color. This is caused by
fb_set_logo_directpalette() which does not initialize the last 32 palette
entries.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
commit 3e680aae4e ("fb: convert
lock/unlock_kernel() into local fb mutex") introduced several deadlocks
in the fb_compat_ioctl() path, as mutex_lock() doesn't allow recursion,
unlike lock_kernel(). This broke frame buffer applications on 64-bit
systems with a 32-bit userland.
commit 120a37470c ("framebuffer compat_ioctl
deadlock") fixed one of the deadlocks.
This patch fixes the remaining deadlocks:
- Revert commit 120a37470c,
- Extract the core logic of fb_ioctl() into a new function do_fb_ioctl(),
- Change all callsites of fb_ioctl() where info->lock is already held to
call do_fb_ioctl() instead,
- Add sparse annotations to all routines that take info->lock.
Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: Krzysztof Helt <krzysztof.h1@wp.pl>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix deadlock in fb_compat_ioctl. fb_compat_ioctl acquires a mutex and
calls fb_ioctl that tries to acquire that mutex too. A regression added
during BKL removal.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change lock_kernel()/unlock_kernel() to local fb mutex. Each frame buffer
instance has its own mutex.
The one line try_to_load() function is unrolled to request_module() in two
places for readability.
[righi.andrea@gmail.com: fb: fix NULL pointer BUG dereference in fb_open()]
Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: Andrea Righi <righi.andrea@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Framebuffer is heavily BKL dependant at the moment so just wrap the ioctl
handler in the driver as we push down.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6: (46 commits)
UIO: Fix mapping of logical and virtual memory
UIO: add automata sercos3 pci card support
UIO: Change driver name of uio_pdrv
UIO: Add alignment warnings for uio-mem
Driver core: add bus_sort_breadthfirst() function
NET: convert the phy_device file to use bus_find_device_by_name
kobject: Cleanup kobject_rename and !CONFIG_SYSFS
kobject: Fix kobject_rename and !CONFIG_SYSFS
sysfs: Make dir and name args to sysfs_notify() const
platform: add new device registration helper
sysfs: use ilookup5() instead of ilookup5_nowait()
PNP: create device attributes via default device attributes
Driver core: make bus_find_device_by_name() more robust
usb: turn dev_warn+WARN_ON combos into dev_WARN
debug: use dev_WARN() rather than WARN_ON() in device_pm_add()
debug: Introduce a dev_WARN() function
sysfs: fix deadlock
device model: Do a quickcheck for driver binding before doing an expensive check
Driver core: Fix cleanup in device_create_vargs().
Driver core: Clarify device cleanup.
...
Straight forward conversions to CONFIG_MODULE; many drivers
include <linux/kmod.h> conditionally and then don't have any
other conditional code so remove it from those.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: video4linux-list@redhat.com
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: linux-ppp@vger.kernel.org
Cc: dm-devel@redhat.com
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Some LCD panels are capable of different resolutions, and is allowed
to change at run-time, so to make "struct lcd_device" to be able to
handle mode change events here.
Signed-off-by: Eric Miao <eric.miao@marvell.com>
Acked-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Fixes kernel BUG at lib/radix-tree.c:473.
Previously the handler was incidentally provided by tmpfs but this was
removed with:
commit 14fcc23fdc
Author: Hugh Dickins <hugh@veritas.com>
Date: Mon Jul 28 15:46:19 2008 -0700
tmpfs: fix kernel BUG in shmem_delete_inode
relying on this behaviour was incorrect in any case and the BUG also
appeared when the device node was on an ext3 filesystem.
v2: override a_ops at open() time rather than mmap() time to minimise
races per AKPM's concerns.
Signed-off-by: Ian Campbell <ijc@hellion.org.uk>
Cc: Jaya Kumar <jayakumar.lkml@gmail.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Johannes Weiner <hannes@saeurebad.de>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Kel Modderman <kel@otaku42.de>
Cc: Markus Armbruster <armbru@redhat.com>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Cc: <stable@kernel.org> [14fcc23fd is in 2.6.25.14 and 2.6.26.1]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, linux/major.h defines a GRAPHDEV_MAJOR (29) that nobody uses,
and linux/fb.h defines the real FB_MAJOR (also 29), that only fbmem.c
needs. Drop GRAPHDEV_MAJOR from major.h, move FB_MAJOR definition from
fb.h to major.h, and fix fbmem.c to use major.h's definition.
Signed-off-by: Philippe De Muyter <phdm@macqel.be>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The xoffset, yoffset and yres members of fb_var_screeninfo are __u32.
Make them unsigned in the code as well.
Signed-off-by: Ville Syrjala <syrjala@sci.fi>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
device_create() is race-prone, so use the race-free
device_create_drvdata() instead as device_create() is going away.
Cc: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Note: looks like accesses to "registered_fb" are done without any exclusion
so there're none in new proc code, too. This should be fixed in separate
patch.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add support for the framebuffers with non-native endianness. This is done via
FBINFO_FOREIGN_ENDIAN flag that will be used by the drivers. Depending on the
host endianness this flag will be overwritten by FBINFO_BE_MATH internal flag,
or cleared.
Tested to work on MPC8360E-RDK (BE) + Fujitsu MINT framebuffer (LE).
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: <Valdis.Kletnieks@vt.edu>
Cc: Clemens Koller <clemens.koller@anagramm.de>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Move the extern declaration for global_mode_option to <linux/fb.h> and rename
the variable to fb_mode_option.
Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The logo code is not and should not be used by modules.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The VGA16 logo (bpp = 4) and monochrome logo (bpp = 1) do not contain any
color information (no CLUT). If the fb depth is > logo depth, these logo's
will not properly display. Fix by using the console palette instead of
creating a new one.
Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add fb_append_extra_logo(), to append extra lines of logos below the standard
Linux logo.
Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Signed-off-by: Geoff Levand <geoffrey.levand@am.sony.com>
Acked-By: James Simmons <jsimmons@infradead.org>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The Cell Broadband Engine contains a 64-bit PowerPC core with 2 hardware
threads (called PPEs) and 8 Synergistic Processing Engines (called SPEs).
When booting Linux, 2 penguins logos are shown on the graphical console by
the standard frame buffer console logo code.
To emphasize the existence of the SPEs (which can be used under Linux), we
added a second row of (smaller) helper penguin logos, one for each SPE.
A sample screenshot can be found at
http://www.kernel.org/pub/linux/kernel/people/geoff/cell/debian-penguin-shot.png
(or on the ps3linux T-shirts we wore at OLS :-)
This patch:
Extract the code to draw one line of logos into fb_show_logo_line()
Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Signed-off-by: Geoff Levand <geoffrey.levand@am.sony.com>
Acked-By: James Simmons <jsimmons@infradead.org>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This allows for proper console unregistration via the VT layer, and updates
the FB layer to use it. This makes debugging new console drivers much easier,
since you can properly clean them up before unloading.
[adaplas]
unregister_framebuffer() is typically called as part of the driver's
module_exit(). Doing so otherwise will freeze the machine as the VT layer is
holding reference counts on fbcon, and fbcon on the driver. With this change,
it allows unregister_framebuffer() to be called safely anywhere as needed.
Additions from the original: If multiple drivers are used by fbcon, and if
one of them unregisters, a driver will take over the consoles vacated by the
outgoing one (via set_con2fb_map). Once only the outgoing driver remains,
then fbcon will unbind from the VT layer (if CONFIG_HW_CONSOLE_UNBINDING is
set to y).
It is important that these drivers implement fb_open() and fb_release()
just to ensure that no other process is using the driver. Likewise, these
drivers _must_ check the return value of unregister_framebuffer().
[akpm@linux-foundation.org: make fbcon_unbind() stub inline]
Signed-off-by: Jesse Barnes <jesse.barnes@intel.com>
Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Move arch-specific bits of fb_mmap() to their respective subdirectories
[bob.picco@hp.com: efi_range_is_wc is referenced but not declared]
[bunk@stusta.de: fix include/asm-m68k/fb.h]
Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Provide framebuffer page protection flags and definitions of
fb_readl/fb_writel for AVR32.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Clean up exit patch of fb_set_var():
- consolidate all return values into a single local variable
- ensure that return values are valid error codes
- fix fb_set_var() returning success when fb_check_caps() failed
Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Check if the mode can properly display the screen. This will be needed by
drivers where the capability is not constant with each mode. The function
fb_set_var() will query fbcon the requirement, then it will query the driver
(via a new hook fb_get_caps()) its capability. If the driver's capability
cannot handle fbcon's requirement, then fb_set_var() will fail.
For example, if a particular driver supports 2 modes where:
mode1 = can only display 8x16 bitmaps
mode2 = can display any bitmap
then if current mode = mode2 and current font = 12x22
fbset <mode1> /* mode1 cannot handle 12x22 */
fbset will fail
Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some drivers may reset the var->activate field on fb_check_var(). This can
lead to undefined behavior. For example, doing fbset -a <option> with vga16fb
will only modify the active console instead of modifying all.
Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A few drivers are not capable of blitting rectangles of any dimension.
vga16fb can only blit 8-pixel wide rectangles, while s3fb (in tileblitting
mode) can only blit 8x16 rectangles. For example, loading a 12x22 font in
vga16fb will result in a corrupt display.
Advertise this limitation/capability in info->pixmap.blit_x and blit_y. These
fields are 32-bit arrays (font max is 32x32 only), ie, if bit 7 is set, then
width/height of 7+1 is supported.
Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It is unnecessary to pass struct file to fb_read() and fb_write() in struct
fb_ops. For consistency with the other methods, pass struct fb_info instead.
Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It was always intended for the logo to be drawn only if both fbcon and the
driver that is mapped to it are both compiled statically. Currently, if fbcon
is loaded prior to the driver, the logo is not shown. Reverse the order, and
the code may attempt to draw the logo which is __initdata. By accident, this
bug is rarely seen because this method of loading the modules is not common
and secondly, a code in fb_prepare_logo() that checks the height of the logo
(now a random value) rarely succeeds.
Fix by drawing the logo only if both fbcon and the driver are statically
compiled.
Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Correct the image offsets when rotating the logo. Before image->dx and
image->dy were always zero, so nobody ever noticed.
Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Acked-By: James Simmons <jsimmons@infradead.org>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fb_do_show_logo() updates:
- Use width and height of the passed image instead of the global variable
fb_logo
- Explicitly pass the number of logos to draw
Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Signed-off-by: Geoff Levand <geoffrey.levand@am.sony.com>
Acked-By: James Simmons <jsimmons@infradead.org>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are cases when we do not want to wait on the delay for automatically
updating the "real" framebuffer, this implements a simple ->fsync() hook
for explicitly flushing the deferred I/O work. The ->page_mkwrite()
handler will rearm the work queue normally.
(akpm: nuke unneeded ifdefs, forward-delcare struct dentry)
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Cc: Jaya Kumar <jayakumar.lkml@gmail.com>
Acked-by: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
After Al Viro (finally) succeeded in removing the sched.h #include in module.h
recently, it makes sense again to remove other superfluous sched.h includes.
There are quite a lot of files which include it but don't actually need
anything defined in there. Presumably these includes were once needed for
macros that used to live in sched.h, but moved to other header files in the
course of cleaning it up.
To ease the pain, this time I did not fiddle with any header files and only
removed #includes from .c-files, which tend to cause less trouble.
Compile tested against 2.6.20-rc2 and 2.6.20-rc2-mm2 (with offsets) on alpha,
arm, i386, ia64, mips, powerpc, and x86_64 with allnoconfig, defconfig,
allmodconfig, and allyesconfig as well as a few randconfigs on x86_64 and all
configs in arch/arm/configs on arm. I also checked that no new warnings were
introduced by the patch (actually, some warnings are removed that were emitted
by unnecessarily included header files).
Signed-off-by: Tim Schmielau <tim@physik3.uni-rostock.de>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- annotate some variables from vgacon.c and fbmem.c as __read_mostly
- move the mask[] array in fb_set_logo_truepalette() into the .rodata section
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Converts from using struct "class_device" to "struct device" making
everything show up properly in /sys/devices/ with symlinks from the
/sys/class directory.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The backlight and lcd subsystems can be notified by the framebuffer layer
of blanking events. However, these subsystems, as a whole, can function
independently from the framebuffer layer. But in order to enable to the
lcd and backlight subsystems, the framebuffer has to be compiled also,
effectively sucking in a huge amount of unneeded code.
To prevent dependency problems, separate out the framebuffer notification
mechanism from the framebuffer layer and permanently link it to the kernel.
Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
MAX_NR_CONSOLES, fg_console, want_console and last_console are more of a
function of the VT layer than the TTY one. Moving these to vt.h and vt_kern.h
allows all of the framebuffer and VT console drivers to remove their
dependency on tty.h.
[akpm@osdl.org: fix alpha build]
Signed-off-by: Jon Smirl <jonsmir@gmail.com>
Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The control for binding/unbinding is moved from fbcon to the console layer.
Thus the fbcon sysfs attributes, attach and detach, are also gone.
1. Add a notifier event that tells fbcon if a framebuffer driver has been
unregistered. If no registered driver remains, fbcon will unregister
itself from the console layer.
2. Replaced calls to give_up_console() with unregister_con_driver().
3. Still use take_over_console() instead of register_con_driver() to
maintain compatibility
4. Respect the parameter first_fb_vc and last_fb_vc instead of using 0 and
MAX_NR_CONSOLES - 1. These parameters are settable by the user.
5. When fbcon is completely unbound from the console layer, fbcon will
also release (iow, decrement module reference counts to zero) all fbdev
drivers. In other words, a bind or unbind request from the console layer
will propagate down to the framebuffer drivers.
6. If fbcon is not bound to the console, it will ignore all notifier
events (except driver registration and unregistration) and all sysfs
requests.
Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
In order for this feature to work, an interface will be needed. The most
appropriate is sysfs. However, the framebuffer console has no sysfs entry
yet. This will create a sysfs class device entry for fbcon under
/sys/class/graphics.
Add a class_device entry 'fbcon' under class 'graphics'. Console-specific
attributes which where previously under class/graphics/fb[x] are moved to
class/graphics/fbcon. These attributes, 'con_rotate' and 'con_rotate_all',
are also renamed to 'rotate' and 'rotate_all' respectively.
Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Clemens Ladisch
