Print out the correct type when the Write Protected (WP) type is seen.
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

J.A. Magallón reported:

 >> Also, on a 64 bit box with 4Gb, it gives this:
 >>
 >> cicely:~# cat /proc/mtrr
 >> reg00: base=0x00000000 (   0MB), size=4096MB: write-back, count=1
 >> reg01: base=0x100000000 (4096MB), size=1024MB: write-back, count=1
 >> reg02: base=0x140000000 (5120MB), size= 512MB: write-back, count=1
 >> reg03: base=0x160000000 (5632MB), size= 256MB: write-back, count=1
 >> reg04: base=0x80000000 (2048MB), size=2048MB: uncachable, count=1

boundary handling has a problem ... fix it.
Reported-by: NJ.A. Magallón <jamagallon@ono.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Patch below cleans up formatting, with space for big bases and sizes (64 Gb).
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This option has been added in v2.6.26 as a default-disabled
feature and went through several revisions since then.

The feature fixes a wide range of MTRR setup problems that BIOSes
leave us with: slow system, slow Xorg, slow system when adding lots
of RAM, etc., so we want to enable it by default for v2.6.28.

See:

  [Bug 10508] Upgrade to 4GB of RAM messes up MTRRs
  http://bugzilla.kernel.org/show_bug.cgi?id=10508

and the test results in:

   http://lkml.org/lkml/2008/9/29/273

1. hpa
reg00: base=0xc0000000 (3072MB), size=1024MB: uncachable, count=1
reg01: base=0x13c000000 (5056MB), size=  64MB: uncachable, count=1
reg02: base=0x00000000 (   0MB), size=4096MB: write-back, count=1
reg03: base=0x100000000 (4096MB), size=1024MB: write-back, count=1
reg04: base=0xbf700000 (3063MB), size=   1MB: uncachable, count=1
reg05: base=0xbf800000 (3064MB), size=   8MB: uncachable, count=1

will get
Found optimal setting for mtrr clean up
gran_size: 1M   chunk_size: 128M        num_reg: 6      lose RAM: 0M
range0: 0000000000000000 - 00000000c0000000
Setting variable MTRR 0, base: 0MB, range: 2048MB, type WB
Setting variable MTRR 1, base: 2048MB, range: 1024MB, type WB
hole: 00000000bf700000 - 00000000c0000000
Setting variable MTRR 2, base: 3063MB, range: 1MB, type UC
Setting variable MTRR 3, base: 3064MB, range: 8MB, type UC
range0: 0000000100000000 - 0000000140000000
Setting variable MTRR 4, base: 4096MB, range: 1024MB, type WB
hole: 000000013c000000 - 0000000140000000
Setting variable MTRR 5, base: 5056MB, range: 64MB, type UC

2. Dylan Taft
reg00: base=0x00000000 (   0MB), size=4096MB: write-back, count=1
reg01: base=0x100000000 (4096MB), size= 512MB: write-back, count=1
reg02: base=0x120000000 (4608MB), size= 256MB: write-back, count=1
reg03: base=0xd0000000 (3328MB), size= 256MB: uncachable, count=1
reg04: base=0xe0000000 (3584MB), size= 512MB: uncachable, count=1
reg05: base=0xc7e00000 (3198MB), size=   2MB: uncachable, count=1
reg06: base=0xc8000000 (3200MB), size= 128MB: uncachable, count=1

will get
Found optimal setting for mtrr clean up
gran_size: 1M   chunk_size: 4M  num_reg: 6      lose RAM: 0M
range0: 0000000000000000 - 00000000c8000000
Setting variable MTRR 0, base: 0MB, range: 2048MB, type WB
Setting variable MTRR 1, base: 2048MB, range: 1024MB, type WB
Setting variable MTRR 2, base: 3072MB, range: 128MB, type WB
hole: 00000000c7e00000 - 00000000c8000000
Setting variable MTRR 3, base: 3198MB, range: 2MB, type UC
rangeX: 0000000100000000 - 0000000130000000
Setting variable MTRR 4, base: 4096MB, range: 512MB, type WB
Setting variable MTRR 5, base: 4608MB, range: 256MB, type WB

3. Gabriel
reg00: base=0xd0000000 (3328MB), size= 256MB: uncachable, count=1
reg01: base=0xe0000000 (3584MB), size= 512MB: uncachable, count=1
reg02: base=0x00000000 (   0MB), size=4096MB: write-back, count=1
reg03: base=0x100000000 (4096MB), size= 512MB: write-back, count=1
reg04: base=0x120000000 (4608MB), size= 128MB: write-back, count=1
reg05: base=0x128000000 (4736MB), size=  64MB: write-back, count=1
reg06: base=0xcf600000 (3318MB), size=   2MB: uncachable, count=1

will get
Found optimal setting for mtrr clean up
gran_size: 1M   chunk_size: 16M         num_reg: 7      lose RAM: 0M
range0: 0000000000000000 - 00000000d0000000
Setting variable MTRR 0, base: 0MB, range: 2048MB, type WB
Setting variable MTRR 1, base: 2048MB, range: 1024MB, type WB
Setting variable MTRR 2, base: 3072MB, range: 256MB, type WB
hole: 00000000cf600000 - 00000000cf800000
Setting variable MTRR 3, base: 3318MB, range: 2MB, type UC
rangeX: 0000000100000000 - 000000012c000000
Setting variable MTRR 4, base: 4096MB, range: 512MB, type WB
Setting variable MTRR 5, base: 4608MB, range: 128MB, type WB
Setting variable MTRR 6, base: 4736MB, range: 64MB, type WB

4. Mika Fischer
reg00: base=0xc0000000 (3072MB), size=1024MB: uncachable, count=1
reg01: base=0x00000000 ( 0MB), size=4096MB: write-back, count=1
reg02: base=0x100000000 (4096MB), size=1024MB: write-back, count=1
reg03: base=0xbf700000 (3063MB), size= 1MB: uncachable, count=1
reg04: base=0xbf800000 (3064MB), size= 8MB: uncachable, count=1

will get
Found optimal setting for mtrr clean up
gran_size: 1M   chunk_size: 16M         num_reg: 5      lose RAM: 0M
range0: 0000000000000000 - 00000000c0000000
Setting variable MTRR 0, base: 0MB, range: 2048MB, type WB
Setting variable MTRR 1, base: 2048MB, range: 1024MB, type WB
hole: 00000000bf700000 - 00000000c0000000
Setting variable MTRR 2, base: 3063MB, range: 1MB, type UC
Setting variable MTRR 3, base: 3064MB, range: 8MB, type UC
rangeX: 0000000100000000 - 0000000140000000
Setting variable MTRR 4, base: 4096MB, range: 1024MB, type WB
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

one have gran < 1M

reg00: base=0xd8000000 (3456MB), size= 128MB: uncachable, count=1
reg01: base=0xe0000000 (3584MB), size= 512MB: uncachable, count=1
reg02: base=0x00000000 (   0MB), size=4096MB: write-back, count=1
reg03: base=0x100000000 (4096MB), size= 512MB: write-back, count=1
reg04: base=0x120000000 (4608MB), size= 128MB: write-back, count=1
reg05: base=0xd7f80000 (3455MB), size= 512KB: uncachable, count=1

will get

Found optimal setting for mtrr clean up
gran_size: 512K         chunk_size: 2M  num_reg: 7      lose RAM: 0G
range0: 0000000000000000 - 00000000d8000000
Setting variable MTRR 0, base: 0GB, range: 2GB, type WB
Setting variable MTRR 1, base: 2GB, range: 1GB, type WB
Setting variable MTRR 2, base: 3GB, range: 256MB, type WB
Setting variable MTRR 3, base: 3328MB, range: 128MB, type WB
hole: 00000000d7f00000 - 00000000d7f80000
Setting variable MTRR 4, base: 3455MB, range: 512KB, type UC
rangeX: 0000000100000000 - 0000000128000000
Setting variable MTRR 5, base: 4GB, range: 512MB, type WB
Setting variable MTRR 6, base: 4608MB, range: 128MB, type WB

so start from 64k instead of 1M
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

make the print out right with size < 1M
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Delay exit to make sure we can actually get the optimal result in as
many cases as possible.
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

v2: should check with half of range0 size instead of chunk_size

So don't have silly big hole.

in hpa's case we could auto detect instead of adding mtrr_chunk_size in
command line.
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

add mtrr_cleanup_debug to print out more info about layout
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

fix hpa's t61 with 4g ram:

   change layout from
	(n - 1)*chunksize + chunk_size - NC
   to
	n*chunksize - NC
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

change back chunksize max to 2g
   otherwise will get strange layout in 2G ram system like
     0 - 4g WB, 2040M - 2048M UC, 2048M -  4G NC
   instead of
     0 - 2g WB, 2040M - 2048M UC
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Commit ee1e2c82 ("IPoIB: Refresh paths instead of flushing them on SM
change events") changed how paths are flushed on an SM event.  This
change introduces a problem if the path record query triggered by
fails, causing path->ah to become NULL.  A later successful path query
will then trigger WARN_ON() in path_rec_completion(), and crash
because path->ah has already been freed, so the ipoib_put_ah() inside
the lock in path_rec_completion() may actually drop the last reference
(contrary to the comment that claims this is safe).

Fix this by updating path->ah and freeing old_ah only when the path
record query is successful.  This prevents the neighbour AH and that
path AH from getting out of sync.

This fixes <https://bugs.openfabrics.org/show_bug.cgi?id=1194>
Reported-by: NRabah Salem <ravah@mellanox.com>
Debugged-by: NEli Cohen <eli@mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6:
  netfilter: ip6t_{hbh,dst}: Rejects not-strict mode on rule insertion
  ath9k: disable MIB interrupts to fix interrupt storm
  [Bluetooth] Fix USB disconnect handling of btusb driver
  [Bluetooth] Fix wrong URB handling of btusb driver
  [Bluetooth] Fix I/O errors on MacBooks with Broadcom chips

* 'i2c-for-linus' of git://jdelvare.pck.nerim.net/jdelvare-2.6:
  i2c: Fix mailing lists in two MAINTAINERS entries
  i2c-dev: Return correct error code on class_create() failure
  i2c-powermac: Fix section for probe and remove functions

Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: prevent stale state of c1e_mask across CPU offline/online, fix

* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus:
  [MIPS] Fixe the definition of PTRS_PER_PGD
  [MIPS] au1000: Fix gpio direction

Make sched_clock() report time since boot rather than time since last
timer interrupt.

Make sched_clock() expand and scale the 32-bit TSC value running at
IOCLK speed (~33MHz) to a 64-bit nanosecond counter, using cnt32_to_63()
acquired from the ARM arch and without using slow DIVU instructions
every call.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Move asm-arm/cnt32_to_63.h to include/linux/ so that MN10300 can make
use of it too.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The current code ignores rules for internal options in HBH/DST options
header in packet processing if 'Not strict' mode is specified (which is not
implemented). Clearly it is not expected by user.

Kernel should reject HBH/DST rule insertion with 'Not strict' mode
in the first place.
Signed-off-by: NYasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs:
  9p: fix put_data error handling
  9p: use an IS_ERR test rather than a NULL test
  9p: introduce missing kfree
  9p-trans_fd: fix and clean up module init/exit paths
  9p-trans_fd: don't do fs segment mangling in p9_fd_poll()
  9p-trans_fd: clean up p9_conn_create()
  9p-trans_fd: fix trans_fd::p9_conn_destroy()
  9p: implement proper trans module refcounting and unregistration

Abhishek Kulkarni pointed out an inconsistency in the way
errors are returned from p9_put_data.  On deeper exploration it
seems the error handling for this path was completely wrong.
This patch adds checks for allocation problems and propagates
errors correctly.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

In case of error, the function p9_client_walk returns an ERR pointer, but
never returns a NULL pointer.  So a NULL test that comes after an IS_ERR
test should be deleted.

The semantic match that finds this problem is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@match_bad_null_test@
expression x, E;
statement S1,S2;
@@
x = p9_client_walk(...)
... when != x = E
*  if (x != NULL)
S1 else S2
// </smpl>
Signed-off-by: NJulien Brunel <brunel@diku.dk>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

Error handling code following a kmalloc should free the allocated data.

The semantic match that finds the problem is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@r exists@
local idexpression x;
statement S;
expression E;
identifier f,l;
position p1,p2;
expression *ptr != NULL;
@@

(
if ((x@p1 = \(kmalloc\|kzalloc\|kcalloc\)(...)) == NULL) S
|
x@p1 = \(kmalloc\|kzalloc\|kcalloc\)(...);
...
if (x == NULL) S
)
<... when != x
     when != if (...) { <+...x...+> }
x->f = E
...>
(
 return \(0\|<+...x...+>\|ptr\);
|
 return@p2 ...;
)

@script:python@
p1 << r.p1;
p2 << r.p2;
@@

print "* file: %s kmalloc %s return %s" % (p1[0].file,p1[0].line,p2[0].line)
// </smpl>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

trans_fd leaked p9_mux_wq on module unload.  Fix it.  While at it,
collapse p9_mux_global_init() into p9_trans_fd_init().  It's easier to
follow this way and the global poll_tasks array is about to removed
anyway.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

p9_fd_poll() is never called with user pointers and f_op->poll()
doesn't expect its arguments to be from userland.  There's no need to
set kernel ds before calling f_op->poll() from p9_fd_poll().  Remove
it.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

* Use kzalloc() to allocate p9_conn and remove 0/NULL initializations.

* Clean up error return paths.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

p9_conn_destroy() first kills all current requests by calling
p9_conn_cancel(), then waits for the request list to be cleared by
waiting on p9_conn->equeue.  After that, polling is stopped and the
trans is destroyed.  This sequence has a few problems.

* Read and write works were never cancelled and the p9_conn can be
  destroyed while the works are running as r/w works remove requests
  from the list and dereference the p9_conn from them.

* The list emptiness wait using p9_conn->equeue wouldn't trigger
  because p9_conn_cancel() always clears all the lists and the only
  way the wait can be triggered is to have another task to issue a
  request between the slim window between p9_conn_cancel() and the
  wait, which isn't safe under the current implementation with or
  without the wait.

This patch fixes the problem by first stopping poll, which can
schedule r/w works, first and cancle r/w works which guarantees that
r/w works are not and will not run from that point and then calling
p9_conn_cancel() and do the rest of destruction.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

9p trans modules aren't refcounted nor were they unregistered
properly.  Fix it.

* Add 9p_trans_module->owner and reference the module on each trans
  instance creation and put it on destruction.

* Protect v9fs_trans_list with a spinlock.  This isn't strictly
  necessary as the list is manipulated only during module loading /
  unloading but it's a good idea to make the API safe.

* Unregister trans modules when the corresponding module is being
  unloaded.

* While at it, kill unnecessary EXPORT_SYMBOL on p9_trans_fd_init().
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

Enabling the MIB interrupts has proven to cause an
interrupt storm after 7 hours of run. We will make use of the
MIB interrupt once we have ANI supported added so for now
to cure this we disable the interrupt.

The interrupt storm can be seen as follows after 7 hours of run
as reported by  Steven Noonan <steven@uplinklabs.net>:

18:28:38          sum   1106.00
18:28:39          sum   1037.62
18:28:40          sum   1069.00
18:28:41          sum   1167.00
18:28:42          sum   1155.00
18:28:43          sum   1339.00
18:28:44          sum  18355.00
18:28:45          sum  17845.45
18:28:46          sum  15285.00
18:28:47          sum  17511.00
18:28:48          sum  17568.69
18:28:49          sum  17704.04
18:28:50          sum  18566.67
18:28:51          sum  18913.13

at 18:28:44 the MIB interrupt kicked off and caused huge
latency which can be seen even on a video he submitted:

http://www.youtube.com/watch?v=4GeCx1gZMpASigned-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Two MAINTAINER entries (I2C/SMBUS STUB DRIVER and SIS 96X I2C/SMBUS
DRIVER) were improperly pointing to the lm-sensors mailing list
instead of the i2c mailing list. Fix them.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Cc: Mark M. Hoffman <mhoffman@lightlink.com>

We need to convert the error pointer from class_create(), else we'll return the
successful return code from register_chrdev() on failure.
Signed-off-by: NSven Wegener <sven.wegener@stealer.net>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

__devexit for i2c_powermac_probe is obviously wrong.  In the definition
of struct platform_driver i2c_powermac_driver the remove function
i2c_powermac_remove is wrapped in __devexit_p, so it should be defined
using __devexit.
Signed-off-by: NUwe Kleine-Koenig <ukleinek@informatik.uni-freiburg.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: NJean Delvare <khali@linux-fr.org>

Fix build error introduced by commit 4faac97d ("x86: prevent stale
state of c1e_mask across CPU offline/online").

process_32.c needs to include idle.h to get the prototype for
c1e_remove_cpu()
Signed-off-by: NMarc Dionne <marc.c.dionne@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

When we use > 4KB's page size the original definition is not consistent
with PGDIR_SIZE. For exeample, if we use 16KB page size the PGDIR_SHIFT is
(14-2) + 14 = 26, PGDIR_SIZE is 2^26，so the PTRS_PER_PGD should be:

	2^32/2^26 = 2^6

but the original definition of PTRS_PER_PGD is 4096 (PGDIR_ORDER = 0).

So, this definition needs to be consistent with the PGDIR_SIZE.

And the new definition is consistent with the PGD init in pagetable_init().
Signed-off-by: NDajie Tan <jiankemeng@gmail.com>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

When setting the direction of one GPIO pin we have to keep the state of the
other pins, hence use binary OR. Also gpio_direction_output() wants to set an
initial value, so add that too.

This fixes a problem with the USB power switch on mtx-1 boards.
Signed-off-by: NBruno Randolf <br1@einfach.org>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6: (23 commits)
  USB: revert recovery from transient errors
  usb: unusual devs patch for Nokia 5310 Music Xpress
  usb: ftdi_sio: add support for Domintell devices
  USB: drivers/usb/musb/: disable it on SuperH
  USB Serial: Sierra: Add MC8785 VID/PID
  USB: serial: add ZTE CDMA Tech id to option driver
  USB: ftdi_sio: Add 0x5050/0x0900 USB IDs (Papouch Quido USB 4/4)
  usb serial: ti_usb_3410_5052 obviously broken by firmware changes
  USB: fsl_usb2_udc: fix VDBG() format string
  USB: unusual_devs addition for RockChip MP3 player
  USB: SERIAL CP2101 add device IDs
  usb-serial: Add Siemens EF81 to PL-2303 hack triggers
  USB: fix EHCI periodic transfers
  usb: musb: fix include path
  USB: Fixing Nokia 3310c in storage mode
  usb gadget: fix omap_udc DMA regression
  USB: update of Documentation/usb/anchors.txt
  USB: fix hcd interrupt disabling
  USB: Correct Sierra Wireless USB EVDO Modem Device ID
  USB: Fix the Nokia 6300 storage-mode.
  ...

Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  timers: fix build error in !oneshot case
  x86: c1e_idle: don't mark TSC unstable if CPU has invariant TSC
  x86: prevent C-states hang on AMD C1E enabled machines
  clockevents: prevent mode mismatch on cpu online
  clockevents: check broadcast device not tick device
  clockevents: prevent stale tick_next_period for onlining CPUs
  x86: prevent stale state of c1e_mask across CPU offline/online
  clockevents: prevent cpu online to interfere with nohz

Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched: fix init_hrtick() section mismatch warning