When considering how many journal credits are needed for modifying a
chunk of data, we need to account for the super block, inode block,
quota blocks and xattr block, indirect/index blocks, also, group bitmap
and group descriptor blocks for new allocation (including data and
indirect/index blocks). There are many places in ext4 do the calculation
on their own and often missed one or two meta blocks, and often they
assume single block allocation, and did not considering the multile
chunk of allocation case.

This patch is trying to cleanup current journal credit code, provides
some common helper funtion to calculate the journal credits, to be used
for writepage, writepages, DIO, fallocate, migration, defrag, and for
both nonextent and extent files.

This patch modified the writepage/write_begin credit caculation for
nonextent files, to use the new helper function. It also fixed the
problem that writepage on nonextent files did not consider the case
blocksize <pagesize, thus could possibelly need multiple block
allocation in a single transaction.
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

The find_group_flex() function starts with best_flex as the
parent_fbg_group, which happens to have 0 inodes free.  Some of the
flex groups searched have free blocks and free inodes, but the
flex_freeb_ratio is < 10, so they're skipped.  Then when a group is
compared to the current "best" flex group, it does not have more free
blocks than "best", so it is skipped as well.

This continues until no flex group with free inodes is found which has
a proper ratio or which has more free blocks than the "best" group,
and we're left with a "best" group that has 0 inodes free, and we
return -ENOSPC.

We fix this by changing the logic so that if the current "best" flex
group has no inodes free, and the current one does have room, it is
promoted to the next "best."
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

When trying to resize an ext4 fs and you run out of reserved gdt blocks,
you get an error that doesn't actually tell you what went wrong, it just
says that the gdb it picked is not correct, which is the case since you
don't have any reserved gdt blocks left.  This patch adds a check to make
sure you have reserved gdt blocks to use, and if not prints out a more
relevant error.
Signed-off-by: Josef Bacik <jbacik@redhat.com>
Cc: <linux-ext4@vger.kernel.org>
Cc: Andreas Dilger <adilger@sun.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

In ext4_ext_truncate(), we should use the more generic
ext4_discard_reservations() call so we do the right thing when the
filesystem is mounted with the nomballoc option.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Mingming Cao <cmm@us.ibm.com>

This fixes a bug where readdir() would return a directory entry twice
if there was a hash collision in an hash tree indexed directory.
Signed-off-by: Eugene Dashevsky <eugene@ibrix.com>
Signed-off-by: Mike Snitzer <msnitzer@ibrix.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

Ext4 will release the reserved blocks for delayed allocations when
inode is truncated/unlinked.  If there is no reserved block at all, we
shouldn't need to do so.  But current code still tries to release the
reserved blocks regardless whether the counters's value is 0.
Continue to do that causes the later calculation to go wrong and a
kernel BUG_ON() caught that. This doesn't happen for extent-based
files, as the calculation for 0 reserved blocks was right for extent
based file.

This patch fixed the kernel BUG() due to above reason.  It adds checks
for 0 to avoid unnecessary release and fix calculation for non-extent
files.
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

We need to call ext4_discard_reservation() earlier in ext4_truncate(),
to avoid a BUG() in ext4_mb_return_to_preallocation(), which is called
(ultimately) by ext4_free_blocks().  So we must ditch the blocks on
i_prealloc_list before we start freeing the data blocks.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

When using fallocate the buffer_heads are marked unwritten and unmapped.
We need to map them in the writepages after a get_block.  Otherwise we
split the uninit extents, but never write the content to disk.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

* 'for-2.6.27' of git://linux-nfs.org/~bfields/linux:
  fs/nfsd/export.c: Adjust error handling code involving auth_domain_put
  MAINTAINERS: mention lockd and sunrpc in nfs entries
  lockd: trivial sparse endian annotations

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband:
  IB/ehca: Discard double CQE for one WR
  IB/ehca: Check idr_find() return value
  IB/ehca: Repoll CQ on invalid opcode
  IB/ehca: Rename goto label in ehca_poll_cq_one()
  IB/ehca: Update qp_state on cached modify_qp()
  IPoIB/cm: Use vmalloc() to allocate rx_rings

* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6:
  [IA64] use bcd2bin/bin2bcd
  [IA64] Ensure cpu0 can access per-cpu variables in early boot code

Various cleanup the drivers/firmware/memmap (after review by AKPM):

    - fix kdoc to conform to the standard
    - move kdoc from header to implementation files
    - remove superfluous WARN_ON() after kmalloc()
    - WARN_ON(x); if (!x) -> if(!WARN_ON(x))
    - improve some comments
Signed-off-by: Bernhard Walle <bwalle@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

My Sun Netra T1 AC200 has one of these... bit harsh not letting me use it
and all :)

==========
alex@woodchuck:~$ lspci -nn
00:01.0 PCI bridge [0604]: Sun Microsystems Computer Corp. Simba Advanced PCI Bridge [108e:5000] (rev 13)
00:01.1 PCI bridge [0604]: Sun Microsystems Computer Corp. Simba Advanced PCI Bridge [108e:5000] (rev 13)
01:03.0 Non-VGA unclassified device [0000]: ALi Corporation M7101 Power Management Controller [PMU] [10b9:7101]
01:05.1 Ethernet controller [0200]: Sun Microsystems Computer Corp. RIO GEM [108e:1101] (rev 01)
01:05.3 USB Controller [0c03]: Sun Microsystems Computer Corp. RIO USB [108e:1103] (rev 01)
01:07.0 ISA bridge [0601]: ALi Corporation M1533/M1535 PCI to ISA Bridge [Aladdin IV/V/V+] [10b9:1533]
01:0c.0 Bridge [0680]: Sun Microsystems Computer Corp. RIO EBUS [108e:1100] (rev 01)
01:0c.1 Ethernet controller [0200]: Sun Microsystems Computer Corp. RIO GEM [108e:1101] (rev 01)
01:0c.3 USB Controller [0c03]: Sun Microsystems Computer Corp. RIO USB [108e:1103] (rev 01)
01:0d.0 IDE interface [0101]: ALi Corporation M5229 IDE [10b9:5229] (rev c3)
02:08.0 SCSI storage controller [0100]: LSI Logic / Symbios Logic 53C896/897 [1000:000b] (rev 07)
02:08.1 SCSI storage controller [0100]: LSI Logic / Symbios Logic 53C896/897 [1000:000b] (rev 07)
==========
Signed-off-by: Alexander Clouter <alex@digriz.org.uk>
Cc: Wim Van Sebroeck <wim@iguana.be>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The attached patch seems to already exist in a number of branches -- it
keeps popping up on Google for me, and is certainly already in Debian --
but is strangely absent from mainstream.

The problem appears to be that the patched file ends up as part of the
target toolchain, but unfortunately the gcc constant folding doesn't
appear to eliminate the __invalid_size_argument_for_IOC value early
enough.  Certainly compiling C++ programs which use _IO...  macros as
constants fails without this patch.
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fix printf format type warnings (seen on alpha & ia64):

Documentation/accounting/getdelays.c:206: warning: format '%15llu' expects type 'long long unsigned int', but argument 6 has type '__u64'
Documentation/accounting/getdelays.c:206: warning: format '%15llu' expects type 'long long unsigned int', but argument 7 has type '__u64'
Documentation/accounting/getdelays.c:206: warning: format '%15llu' expects type 'long long unsigned int', but argument 8 has type '__u64'
Documentation/accounting/getdelays.c:206: warning: format '%15llu' expects type 'long long unsigned int', but argument 9 has type '__u64'
Documentation/accounting/getdelays.c:206: warning: format '%15llu' expects type 'long long unsigned int', but argument 12 has type '__u64'
Documentation/accounting/getdelays.c:206: warning: format '%15llu' expects type 'long long unsigned int', but argument 13 has type '__u64'
Documentation/accounting/getdelays.c:206: warning: format '%15llu' expects type 'long long unsigned int', but argument 16 has type '__u64'
Documentation/accounting/getdelays.c:206: warning: format '%15llu' expects type 'long long unsigned int', but argument 17 has type '__u64'
Documentation/accounting/getdelays.c:214: warning: format '%15llu' expects type 'long long unsigned int', but argument 4 has type '__u64'
Documentation/accounting/getdelays.c:214: warning: format '%15llu' expects type 'long long unsigned int', but argument 5 has type '__u64'
Documentation/accounting/getdelays.c:221: warning: format '%llu' expects type 'long long unsigned int', but argument 2 has type '__u64'
Documentation/accounting/getdelays.c:221: warning: format '%llu' expects type 'long long unsigned int', but argument 3 has type '__u64'
Documentation/accounting/getdelays.c:221: warning: format '%llu' expects type 'long long unsigned int', but argument 4 has type '__u64'
Documentation/accounting/getdelays.c:221: warning: format '%llu' expects type 'long long unsigned int', but argument 5 has type '__u64'
Documentation/accounting/getdelays.c:221: warning: format '%llu' expects type 'long long unsigned int', but argument 6 has type '__u64'
Documentation/accounting/getdelays.c:236: warning: 'cmd_type' may be used uninitialized in this function
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fix differing signedness warning:

Documentation/pcmcia/crc32hash.c:29: warning: pointer targets in passing argument 1 of 'crc32' differ in signedness
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Documentation/networking/ifenslave.c:1084: warning: pointer targets in assignment differ in signedness

>From include/linux/socket.h:
 *	1003.1g requires sa_family_t and that sa_data is char.

and from SUSv3:
(http://www.opengroup.org/onlinepubs/009695399/basedefs/sys/socket.h.html)

The <sys/socket.h> header shall define the sockaddr structure that includes at least the following members:

sa_family_t  sa_family  Address family.
char         sa_data[]  Socket address (variable-length data).
<end SUSv3>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Add MODULE_LICENSE() to DocBook/procfs_example.c since modpost complained
about a missing license there.

Remove tty procfs removal since the creation was deleted long ago
(http://git.kernel.org/?p=linux/kernel/git/tglx/history.git;a=commitdiff;h=5ad9cb65e9b15e5b83e2dd1c10a4bcaccc4ec644).
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: <J.A.K.Mouw@its.tudelft.nl>
Cc: Sam Ravnborg <sam@ravnborg.org>
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>

Currently source files in the Documentation/ sub-dir can easily bit-rot
since they are not generally buildable, either because they are hidden in
text files or because there are no Makefile rules for them.  This needs to
be fixed so that the source files remain usable and good examples of code
instead of bad examples.

Add the ability to build source files that are in the Documentation/ dir.
Add to Kconfig as "BUILD_DOCSRC" config symbol.

Use "CONFIG_BUILD_DOCSRC=1 make ..." to build objects from the
Documentation/ sources.  Or enable BUILD_DOCSRC in the *config system.
However, this symbol depends on HEADERS_CHECK since the header files need
to be installed (for userspace builds).

Built (using cross-tools) for x86-64, i386, alpha, ia64, sparc32,
sparc64, powerpc, sh, m68k, & mips.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Collect the implementations from include/linux/byteorder/swab.h, swabb.h
in swab.h

The functionality provided covers:
u16 swab16(u16 val) - return a byteswapped 16 bit value
u32 swab32(u32 val) - return a byteswapped 32 bit value
u64 swab64(u64 val) - return a byteswapped 64 bit value
u32 swahw32(u32 val) - return a wordswapped 32 bit value
u32 swahb32(u32 val) - return a high/low byteswapped 32 bit value

Similar to above, but return swapped value from a naturally-aligned pointer
u16 swab16p(u16 *p)
u32 swab32p(u32 *p)
u64 swab64p(u64 *p)
u32 swahw32p(u32 *p)
u32 swahb32p(u32 *p)

Similar to above, but swap the value in-place (in-situ)
void swab16s(u16 *p)
void swab32s(u32 *p)
void swab64s(u64 *p)
void swahw32s(u32 *p)
void swahb32s(u32 *p)

Arches can override any of these with an optimized version by defining an
inline in their asm/byteorder.h (example given for swab16()):

u16 __arch_swab16() {}
 #define __arch_swab16 __arch_swab16
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Switch /proc/irq/*/smp_affinity , /proc/irq/default_smp_affinity to
seq_files.

cat(1) reads with 1024 chunks by default, with high enough NR_CPUS, there
will be -EINVAL.

As side effect, there are now two less users of the ->read_proc interface.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Paul Jackson <pj@sgi.com>
Cc: Mike Travis <travis@sgi.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Short enough reads from /proc/irq/*/smp_affinity return -EINVAL for no
good reason.

This became noticed with NR_CPUS=4096 patches, when length of printed
representation of cpumask becase 1152, but cat(1) continued to read with
1024-byte chunks.  bitmap_scnprintf() in good faith fills buffer, returns
1023, check returns -EINVAL.

Fix it by switching to seq_file, so handler will just fill buffer and
doesn't care about offsets, length, filling EOF and all this crap.

For that add seq_bitmap(), and wrappers around it -- seq_cpumask() and
seq_nodemask().
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Paul Jackson <pj@sgi.com>
Cc: Mike Travis <travis@sgi.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Removed duplicated #include <linux/quotaops.h> in
fs/reiserfs/super.c.
Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The `size' argument was removed.
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ulrich Drepper <drepper@redhat.com>
Cc: Davide Libenzi <davidel@xmailserver.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: Uwe Kleine-König <Uwe.Kleine-Koenig@digi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fix wrong conversion function used by strict_strtou*
Signed-off-by: Yi Yang <yi.y.yang@intel.com>
Reported-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Adjust and honor the vc_scrl_erase_char for 256 and 512 character fonts.

It fixes the issue with disappearing cursor during scrolling
(http://bugzilla.kernel.org/show_bug.cgi?id=11258).  The issue was
reported and tracked by Peter Hanzel.
Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Reported-by: Peter Hanzel <hanzelpeter@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Specify how much physically continuous, DMA capable memory will be
allocated at driver initialization time.  This allow to create framebuffer
device with larger virtual resolution.  Combine with y-panning this can be
used to implement double buffering acceleration method.
Signed-off-by: Stanislaw Gruszka <stf_xl@wp.pl>
Acked-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Acked-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Panning in the y-direction can be done by simply changing the DMA base
address.  This code is already in place, but FBIOPAN_DISPLAY will
currently fail because ypanstep is 0.

Set ypanstep to 1 to indicate that we do support y-panning and also set
the necessary acceleration flags on AT91 (AVR32 already have them.)
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Acked-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The legacy i2c model is going away soon, so switch to the new model.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Cc: Petr Vandrovec <VANDROVE@vc.cvut.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Clean up the use of structure templates in i2c-matroxfb. In this case
it's more efficient to initialize the few fields we need individually.
This makes i2c-matroxfb.ko 16% smaller on my system.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Cc: Petr Vandrovec <VANDROVE@vc.cvut.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

I broke an error path with d03c21ec,
sorry about that.

The machine will crash if the i2c_attach_client() or maven_init_client()
calls fail, although nobody has yet reported this happening.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Cc: Petr Vandrovec <VANDROVE@vc.cvut.cz>
Cc: <stable@kernel.org>		[2.6.25.x, 2.6.26.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: MinChan Kim <minchan.kim@gmail.com>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fix preprocessor symbol so that sparse sees it and does not generate
errors:

  drivers/misc/sgi-gru/grutables.h:286:2: error: "Unsupported architecture"
  drivers/misc/sgi-gru/grutables.h:286:2: error: "Unsupported architecture"
  drivers/misc/sgi-gru/grutables.h:286:2: error: "Unsupported architecture"
  drivers/misc/sgi-gru/grutables.h:286:2: error: "Unsupported architecture"
  drivers/misc/sgi-gru/grutlbpurge.c:185:11: error: undefined identifier 'GRUREGION'
  drivers/misc/sgi-gru/grutables.h:286:2: error: "Unsupported architecture"
  drivers/misc/sgi-gru/grutables.h:286:2: error: "Unsupported architecture"
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Some chips appear to have the 2D engine hang during screen redraw,
typically in a sequence of copyarea operations. This appear to be
solved by adding a flush of the engine destination pixel cache
and waiting for the engine to be idle before issuing the accel
operation. The performance impact seems to be fairly small.

Here is a trace on an RV370 (PCI device ID 0x5b64), it records the
RBBM_STATUS register, then the source x/y, destination x/y, and
width/height used for the copy:

----------------------------------------
radeonfb_prim_copyarea: STATUS[00000140] src[210:70] dst[210:60] wh[a0:10]
radeonfb_prim_copyarea: STATUS[00000140] src[2b8:70] dst[2b8:60] wh[88:10]
radeonfb_prim_copyarea: STATUS[00000140] src[348:70] dst[348:60] wh[40:10]
radeonfb_prim_copyarea: STATUS[80020140] src[390:70] dst[390:60] wh[88:10]
radeonfb_prim_copyarea: STATUS[8002613f] src[40:80] dst[40:70] wh[28:10]
radeonfb_prim_copyarea: STATUS[80026139] src[a8:80] dst[a8:70] wh[38:10]
radeonfb_prim_copyarea: STATUS[80026133] src[e8:80] dst[e8:70] wh[80:10]
radeonfb_prim_copyarea: STATUS[8002612d] src[170:80] dst[170:70] wh[30:10]
radeonfb_prim_copyarea: STATUS[80026127] src[1a8:80] dst[1a8:70] wh[8:10]
radeonfb_prim_copyarea: STATUS[80026121] src[1b8:80] dst[1b8:70] wh[88:10]
radeonfb_prim_copyarea: STATUS[8002611b] src[248:80] dst[248:70] wh[68:10]
----------------------------------------

When things are going fine the copies complete before the next ROP is
even issued, but all of a sudden the 2D unit becomes active (bit 17 in
RBBM_STATUS) and the FIFO retry (bit 13) and FIFO pipeline busy (bit
14) are set as well.  The FIFO begins to backup until it becomes full.

What happens next is the radeon_fifo_wait() times out, and we access
the chip illegally leading to a bus error which usually wedges the
box.  None of this makes it to the console screen, of course :-)
radeon_fifo_wait() should be modified to reset the accelerator when
this timeout happens instead of programming the chip anyways.

----------------------------------------
radeonfb: FIFO Timeout !
ERROR(0): Cheetah error trap taken afsr[0010080005000000] afar[000007f900800e40] TL1(0)
ERROR(0): TPC[595114] TNPC[595118] O7[459788] TSTATE[11009601]
ERROR(0): TPC<radeonfb_copyarea+0xfc/0x248>
ERROR(0): M_SYND(0),  E_SYND(0), Privileged
ERROR(0): Highest priority error (0000080000000000) "Bus error response from system bus"
ERROR(0): D-cache idx[0] tag[0000000000000000] utag[0000000000000000] stag[0000000000000000]
ERROR(0): D-cache data0[0000000000000000] data1[0000000000000000] data2[0000000000000000] data3[0000000000000000]
ERROR(0): I-cache idx[0] tag[0000000000000000] utag[0000000000000000] stag[0000000000000000] u[0000000000000000] l[00\

ERROR(0): I-cache INSN0[0000000000000000] INSN1[0000000000000000] INSN2[0000000000000000] INSN3[0000000000000000]
ERROR(0): I-cache INSN4[0000000000000000] INSN5[0000000000000000] INSN6[0000000000000000] INSN7[0000000000000000]
ERROR(0): E-cache idx[800e40] tag[000000000e049f4c]
ERROR(0): E-cache data0[fffff8127d300180] data1[00000000004b5384] data2[0000000000000000] data3[0000000000000000]
Ker:xnel panic - not syncing: Irrecoverable deferred error trap.
----------------------------------------

Another quirk is that these copyarea calls will not happen until the
first drivers/char/vt.c:redraw_screen() occurs.  This will only happen
if you 1) VC switch or 2) run "consolechars" or 3) unblank the screen.

This seems to happen because until a redraw_screen() the screen scrolling
method used by fbcon is not finalized yet.  I've seen this with other fb
drivers too.

So if all you do is boot straight into X you will never see this bug on
the relevant chips.
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: <stable@kernel.org>		[2.6.25.x, 2.6.26.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

[Andrew this should replace the previous version which did not check
the returns from the region prepare for errors.  This has been tested by
us and Gerald and it looks good.

Bah, while reviewing the locking based on your previous email I spotted
that we need to check the return from the vma_needs_reservation call for
allocation errors.  Here is an updated patch to correct this.  This passes
testing here.]
Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Tested-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>