[JFFS2] Fix hanging close for /dev/mtd character device.

When pdflush is erasing lots of sectors, drivers calling
mtd->sync will hang until all blocks are erased. Be nicer.

Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
[MTD] Only call mtd->sync() method in mtdchar close if opened for write.

Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
[JFFS2] Use point(), if available, to check newly erased blocks.

Faster and won't trash the D-cache.

Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
[JFFS2] Prevent oops after 'node added in wrong place' debug check

jffs2_add_physical_node_ref() should never really return error -- it's
an internal debugging check which triggered. We really need to work out
why and stop it happening. But in the meantime, let's make the failure
mode a little less nasty.

Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
[JFFS2] Reduce time for which erase_free_sem is held during erase.

With current desing erase_free_sem is locked every time the flash
block is being erased. For NOR flashes - ~1 second is needed to erase
single flash block. In the worst case scenario erase_free_sem may be
locked for a couple of seconds when the number of blocks is being
erased (e.g. after large file was removed). When erase_free_sem is
locked all read/write operations for given JFFS2 partition are locked
too - in effect from time to time access to the JFFS2 partition is
locked for a number of seconds. This fix makes critical section in
flash erasing procedure shorter - now erase_free_sem is locked around
erase_completion_lock spinlock only.

Originally from Radoslaw Bisewski
Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
[JFFS2] Improve diagnostic output for 'node added in wrong place' check

Jocke has seen this fail. We want to know why.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
[JFFS2] Fix suspend failure with JFFS2 GC thread.

The try_to_freeze() call was in the wrong place; we need it in the
signal-pending loop now that a pending freeze also makes
signal_pending() return true.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
[MTD] Remove references to ROOT_DEV from map drivers.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
[MTD] [NAND] at91_nand rdy_pin fix

The patch below fixes nand driver for AT91 boards which do not have NAND
R/B signal connected to gpio (rdy_pin is not connected).

Signed-off-by: Ivan Kuten <ivan.kuten@promwad.com>
Acked-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
[MTD] oops and panic message logging to MTD device

Kernel oops and panic messages are invaluable when debugging crashes.
These messages often don't make it to flash based logging methods (say a
syslog on jffs2) due to the overheads involved in writing to flash.

This patch allows you to turn an MTD partition into a circular log
buffer where kernel oops and panic messages are written to. The messages
are obtained by registering a console driver and checking
oops_in_progress. Erases are performed in advance to maximise the
chances of a saving messages.

To activate it, add console=ttyMTDx to the kernel commandline (where x
is the mtd device number to use).

Signed-off-by: Richard Purdie <rpurdie@openedhand.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
[MTD] [NAND] nand_base.c: fix type of eccpos pointer

The nand_base.c driver implicitly casts the uint32_t
eccpos array to 'int *', which is not only not guaranteed
to be the same sign as the source, but is not guaranteed
to be the same size.

Fix by changing nand_base.c to use uint32_t
referencing the eccpos fields.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
[MTD] mtd_blkdevs.c: do not export 'mtd_blktrans_ops'

The mtd_blktrans_ops is not defined in any of the headers
and is indeed not used elsewhere in the kernel, so mark it
as static to reduce the warnings from sparse

drivers/mtd/mtd_blkdevs.c:204:32: warning: symbol 'mtd_blktrans_ops' was not declared. Should it be static?

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
[MTD] [NOR] cfi_cmdset_0002.c: fix 'cfi_amdstd_erase_varsize' to be static

Make cfi_amdstd_erase_varsize static, as declared at the top
of the file to ensure sparse does not print a warning for an
undeclared function, as so:

drivers/mtd/chips/cfi_cmdset_0002.c:1612:5: warning: symbol 'cfi_amdstd_erase_varsize' was not declared. Should it be static?

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
[MTD] [NOR] cfi_cmdset_0001.c: sparse fixes

Fix sparse warnings generated from cfi_cmdset_0001.c.

drivers/mtd/chips/cfi_cmdset_0001.c:1783:5: warning: symbol 'cfi_intelext_erase_varsize' was not declared. Should it be static?
drivers/mtd/chips/cfi_cmdset_0001.c:2258:43: warning: Using plain integer as NULL pointer

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
[MTD] mtdcore.c: share syms with mtd_blkdev.c

Fix the sparse warnings generated by the implicit
dependency of mtd_blkdevs.c and mtd_core.c for the
two symbols mtd_table and mtd_table_mutex. This is
done by adding an local header file mtdcore.h to
define these (including the warning about the
non-proliferation of these symbols).

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
[MTD] [NAND] Change NDFC driver to support 405 platforms too

This patch adds 405 platform support to the 440 NDFC driver. The new
AMCC 405EZ PPC is equipped with the same NDFC core as the 440EP(x)
and other will follow soon.

Signed-off-by: Stefan Roese <sr@denx.de>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
[MTD] m25p80 converted to mutex

Convert semaphore usage in m25p80 driver to mutex; mention another kind of
SPI flash chip that should be able to use this driver (given minor tweaks).

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
[MTD] m25p80 handles more chips, uses JEDEC ids and small eraseblocks

Update chip ID tables in m25p80 to handle more SPI flash chips, matching
datasheets.  All of these can use the same core operations and are newer
chips that support the JEDEC "read id" instruction:

 - Atmel AT25 and AT26 (seven chips)
 - Spansion S25SL (five chips)
 - SST 25VF (four chips)
 - ST M25, M45 (five more chips)
 - Winbond W25X series (seven chips)

That JEDEC instruction is now used, either to support a sanity check on the
platform data holding board configuration data, or to determine chip type
when it's not included in platform data.  In fact, boards that don't need a
standard partition table may not need that platform data any more.

For chips that support 4KiB erase units, use that smaller block size instead
of the larger size (usually 64KiB); it's less wasteful.  (Tested on W25X80.)

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
[MTD] m25p80: Use correct units for binary multiples

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
[MTD] Use mutex instead of semaphore in dataflash driver

The MTD DataFlash driver uses a semaphore as mutex.  Use the mutex API instead
of the (binary) semaphore.

Signed-off-by: Matthias Kaehlcke <matthias.kaehlcke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>