Commit Graph

95 Commits

Author SHA1 Message Date
Jilin Yuan ec1f97f501 ubi: Fix repeated words in comments
Delete the redundant word 'a'.
Delete the redundant word 'the'.

Signed-off-by: Jilin Yuan <yuanjilin@cdjrlc.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2022-09-21 11:32:27 +02:00
Jubin Zhong cf0838dfa3 ubi: remove dead code in validate_vid_hdr()
data_size is already checked against zero when vol_type matches
UBI_VID_STATIC. Remove the following dead code.

Signed-off-by: Jubin Zhong <zhongjubin@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2021-02-12 21:53:22 +01:00
Pratyush Yadav f669e74be8 ubi: Do not zero out EC and VID on ECC-ed NOR flashes
For NOR flashes EC and VID are zeroed out before an erase is issued to
make sure UBI does not mistakenly treat the PEB as used and associate it
with an LEB.

But on some flashes, like the Cypress Semper S28 SPI NOR flash family,
multi-pass page programming is not allowed on the default ECC scheme.
This means zeroing out these magic numbers will result in the flash
throwing a page programming error.

Do not zero out EC and VID for such flashes. A writesize > 1 is an
indication of an ECC-ed flash.

Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Reviewed-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2020-12-13 21:57:21 +01:00
Christoph Hellwig 88dca4ca5a mm: remove the pgprot argument to __vmalloc
The pgprot argument to __vmalloc is always PAGE_KERNEL now, so remove it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Michael Kelley <mikelley@microsoft.com> [hyperv]
Acked-by: Gao Xiang <xiang@kernel.org> [erofs]
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Wei Liu <wei.liu@kernel.org>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Link: http://lkml.kernel.org/r/20200414131348.444715-22-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-02 10:59:11 -07:00
Thomas Gleixner 1a59d1b8e0 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version this program is distributed in the
  hope that it will be useful but without any warranty without even
  the implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details you
  should have received a copy of the gnu general public license along
  with this program if not write to the free software foundation inc
  59 temple place suite 330 boston ma 02111 1307 usa

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1334 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:35 -07:00
Boris Brezillon 8f347c4232 mtd: Unconditionally update ->fail_addr and ->addr in part_erase()
->fail_addr and ->addr can be updated no matter the result of
parent->_erase(), we just need to remove the code doing the same thing
in mtd_erase_callback() to avoid adjusting those fields twice.

Note that this can be done because all MTD users have been converted to
not pass an erase_info->callback() and are thus only taking the
->addr_fail and ->addr fields into account after part_erase() has
returned.

While we're at it, get rid of the erase_info->mtd field which was only
needed to let mtd_erase_callback() get the partition device back.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Reviewed-by: Richard Weinberger <richard@nod.at>
2018-03-15 18:22:26 +01:00
Boris Brezillon 884cfd9023 mtd: Stop assuming mtd_erase() is asynchronous
None of the mtd->_erase() implementations work in an asynchronous manner,
so let's simplify MTD users that call mtd_erase(). All they need to do
is check the value returned by mtd_erase() and assume that != 0 means
failure.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Reviewed-by: Richard Weinberger <richard@nod.at>
2018-03-15 18:21:07 +01:00
Andrew F. Davis 2fae13124f UBI: Fix typos
Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2017-03-24 15:33:32 +01:00
Boris Brezillon 3291b52f9f UBI: introduce the VID buffer concept
Currently, all VID headers are allocated and freed using the
ubi_zalloc_vid_hdr() and ubi_free_vid_hdr() function. These functions
make sure to align allocation on ubi->vid_hdr_alsize and adjust the
vid_hdr pointer to match the ubi->vid_hdr_shift requirements.
This works fine, but is a bit convoluted.
Moreover, the future introduction of LEB consolidation (needed to support
MLC/TLC NANDs) will allows a VID buffer to contain more than one VID
header.

Hence the creation of a ubi_vid_io_buf struct to attach extra information
to the VID header.

We currently only store the actual pointer of the underlying buffer, but
will soon add the number of VID headers contained in the buffer.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2016-10-02 22:48:14 +02:00
Sascha Hauer 8a8e8d2fdb ubi: Only read necessary size when reading the VID header
When reading the vid hdr from the device UBI always reads a whole
page. Instead, read only the data we actually need and speed up
attachment of UBI devices by potentially making use of reading
subpages if the NAND driver supports it.

Since the VID header may be at offset vid_hdr_shift in the page and
we can only read from the beginning of a page we have to add that
offset to the read size.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Richard Weinberger <richard@nod.at>
2016-07-29 23:29:44 +02:00
Brian Norris 2e69d4912f UBI: fix use of "VID" vs. "EC" in header self-check
Looks like a typo, using UBI_EC_HDR_SIZE_CRC (note the "EC") to compute
the CRC for the VID header.

This shouldn't cause any functional change, as both structures are 64
bytes. Verified with:

	BUILD_BUG_ON(UBI_VID_HDR_SIZE_CRC != UBI_EC_HDR_SIZE_CRC);

Reported here:
http://lists.infradead.org/pipermail/linux-mtd/2013-September/048570.html

Reported by: Bill Pringlemeir <bpringlemeir@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2015-12-16 22:46:26 +01:00
Richard Weinberger 281fda2767 UBI: Validate data_size
Make sure that data_size is less than LEB size.
Otherwise a handcrafted UBI image is able to trigger
an out of bounds memory access in ubi_compare_lebs().

Cc: stable@vger.kernel.org
Signed-off-by: Richard Weinberger <richard@nod.at>
Reviewed-by: David Gstir <david@sigma-star.at>
2015-09-29 12:47:04 +02:00
david.oberhollenzer@sigma-star.at 5026906742 UBI: power cut emulation for testing
Emulate random power cuts by switching device to ro after a number of
writes to allow simple power cut testing with nand-sim.

Maximum and minimum number of successful writes before power cut and
what kind of writes (EC header, VID header or none) to interrupt
configurable via debugfs.

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
Signed-off-by: Richard Weinberger <richard@nod.at>
2015-04-13 21:05:17 +02:00
Tanya Brokhman 45fc5c81d0 UBI: extend UBI layer debug/messaging capabilities - cosmetics
Some cosmetic fixes to the patch "UBI: Extend UBI layer debug/messaging
capabilities".

Signed-off-by: Tanya Brokhman <tlinder@codeaurora.org>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
2015-01-28 16:09:09 +01:00
Tanya Brokhman 3260870331 UBI: Extend UBI layer debug/messaging capabilities
If there is more then one UBI device mounted, there is no way to
distinguish between messages from different UBI devices.
Add device number to all ubi layer message types.

The R/O block driver messages were replaced by pr_* since
ubi_device structure is not used by it.

Amended a bit by Artem.

Signed-off-by: Tanya Brokhman <tlinder@codeaurora.org>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
2014-11-07 12:08:51 +02:00
Qi Wang 王起 (qiwang) 2c7ca5cc36 UBI: avoid program operation on NOR flash after erasure interrupted
nor_erase_prepare() will be called before erase a NOR flash, it will program '0'
into a block to mark this block. But program data into a erasure interrupted block
can cause program timtout(several minutes at most) error, could impact other
operation on NOR flash. So UBIFS can read this block first to avoid unneeded
program operation.

This patch try to put read operation at head of write operation in
nor_erase_prepare(), read out the data.
If the data is already corrupt, then no need to program any data into this block,
just go to erase this block.

This patch is validated on Micron NOR flash, part number is:JS28F512M29EWHA

Signed-off-by: Qi Wang <qiwang@micron.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
2014-01-09 18:25:38 +02:00
Ezequiel Garcia 64575574f2 UBI: introduce helpers dbg_chk_{io, gen}
With this patch code is a bit more readable and there's no
generated code or functionality impact.
Furthermore, this abstracts implementation details and
will allow to change ubi_debug_info in a less invasive way.

Signed-off-by: Ezequiel Garcia <elezegarcia@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
2012-12-10 13:38:59 +02:00
Artem Bityutskiy 719bb84017 UBI: print less
UBI currently prints a lot of information when it mounts a volume, which
bothers some people. Make it less chatty - print only important information
by default.

Get rid of 'dbg_msg()' macro completely.

Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
2012-09-04 09:39:02 +03:00
Artem Bityutskiy 049333cecb UBI: comply with coding style
Join all the split printk lines in order to stop checkpatch complaining.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
2012-09-04 09:39:01 +03:00
Artem Bityutskiy fbd0107f4d UBI: amend comments after all the renamings
This patch amends commentaries in scan.[ch] to match the new logic. Reminder -
we did the restructuring to prepare the code for adding the fastmap. This patch
also renames a couple of functions - it was too difficult to separate out that
change and I decided that it is not too bad to have it in the same patch with
commentaries changes.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
2012-05-20 20:26:04 +03:00
Artem Bityutskiy 97d6104bac UBI: rename few functions for consistency
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
2012-05-20 20:26:01 +03:00
Artem Bityutskiy e2986827d5 UBI: get rid of dbg_err
This patch removes the 'dbg_err()' macro and we now use 'ubi_err' instead.
The idea of 'dbg_err()' was to compile out some error message to make the
binary a bit smaller - but I think it was a bad idea.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
2012-05-20 20:26:00 +03:00
Artem Bityutskiy 8056eb4ac4 UBI: clean-up terminology for self-checks in io.c
We have the "sefl-check" feature in UBI, but for historical reasons many
corresponding functions and commentaries in the code use term "paranoid check"
instead. Let's clean this up and use "self-check" everywhere.

This patch renames functions, amends comments and messages. It touches only the
io.c file.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
2012-05-20 20:26:00 +03:00
Artem Bityutskiy aa44d1d35f UBI: remove Kconfig debugging option
This patch kills the UBI debugging Kconfig option completely and makes all the
debugging stuff to be always compiled-in. It was pain in the neck to maintain
this useless option because all users I am aware of have debugging enabled
anyway - how else will you diagnose errors otherwise?

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
2012-05-20 20:26:00 +03:00
Artem Bityutskiy f01e2d1654 UBI: always warn if case of I/O errors
Currently UBI silently retries I/O operation in case of errors. This patch
makes it emit a warning before retrying. This should allow users notice issues
earlier.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
2012-05-20 20:25:58 +03:00
Artem Bityutskiy a904e3f1de UBI: always dump VID and EC headers in case of errors
UBI (and UBIFS) are a bit over-engineered WRT debugging. The idea was to
link as few as possible when debugging is disabled, but the downside is
that most people produce bug reports which are difficult to understand.

Always dump the VID and EC headers' contents in case of errors when it
is helpful.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
2012-05-20 20:25:58 +03:00
Artem Bityutskiy ef7088e7f8 UBI: always dump flash contents in case of errors
UBI (and UBIFS) are a bit over-engineered WRT debugging. The idea was to
link as few as possible when debugging is disabled, but the downside is
that most people produce bug reports which are difficult to understand.

Always dump the flash contents in case of errors, not only when debugging is
enabled.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@linux.intel.com>
2012-05-20 20:25:58 +03:00
Artem Bityutskiy 25886a368d UBI: always dump the stack on error
UBI (and UBIFS) are a bit over-engineered WRT debugging. The idea was to
link as few as possible when debugging is disabled, but the downside is
that most people produce bug reports which are difficult to understand.

This patch weeds out the 'ubi_dbg_dump_stack()' function and turns it
into 'dump_stack()' - it is always useful to have stack dump in case of
an error.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@linux.intel.com>
2012-05-20 20:25:58 +03:00
Artem Bityutskiy 0ca39d74de UBI: rename peb_buf1 to peb_buf
Now we have only one buffer so let's rename it to just 'peb_buf1'.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
2012-03-09 09:39:31 +02:00
Artem Bityutskiy 5942ddbc50 mtd: introduce mtd_block_markbad interface
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2012-01-09 18:25:48 +00:00
Artem Bityutskiy 7086c19d07 mtd: introduce mtd_block_isbad interface
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2012-01-09 18:25:47 +00:00
Artem Bityutskiy eda95cbf75 mtd: introduce mtd_write interface
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2012-01-09 18:25:20 +00:00
Artem Bityutskiy 329ad399a9 mtd: introduce mtd_read interface
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2012-01-09 18:25:19 +00:00
Artem Bityutskiy 7e1f0dc055 mtd: introduce mtd_erase interface
This patch is part of a patch-set which changes the MTD interface
from 'mtd->func()' form to 'mtd_func()' form. We need this because
we want to add common code to to all drivers in the mtd core level,
which is impossible with the current interface when MTD clients
call driver functions like 'read()' or 'write()' directly.

At this point we just introduce a new inline wrapper function, but
later some of them are expected to gain more code. E.g., the input
parameters check should be moved to the wrappers rather than be
duplicated at many drivers.

This particular patch introduced the 'mtd_erase()' interface. The
following patches add all the other interfaces one by one.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2012-01-09 18:25:11 +00:00
Brian Norris d57f40544a mtd: utilize `mtd_is_*()' functions
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
2011-09-21 09:19:06 +03:00
Artem Bityutskiy 27a0f2a37a UBI: prepare debugging stuff to further debugfs conversion
We'll need the 'struct ubi_device *ubi' pointer in every debugging function (to
access the ->dbg field), so add this pointer to all the functions implementing
UBI debugging test modes like 'ubi_dbg_is_bitflip()' etc.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-06-01 11:21:52 +03:00
Artem Bityutskiy 2a734bb8d5 UBI: use debugfs for the extra checks knobs
This patch introduces debugfs support to UBI. All the UBI stuff is kept in the
"ubi" debugfs directory, which contains per-UBI device "ubi/ubiX"
sub-directories, containing debugging files. This file also creates
"ubi/ubiX/chk_gen" and "ubi/ubiX/chk_io" knobs for switching general and I/O
extra checks on and off. And it removes the 'debug_chks' UBI module parameters.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-06-01 11:21:47 +03:00
Artem Bityutskiy 1426414431 UBI: fix typo in a message
When a PEB passes the torture test, UBI prints
"do not mark it a bad", but should print "do not mark it as bad".
This patch corrects the typo.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-04-14 13:38:59 +03:00
Artem Bityutskiy feddbb34eb UBI: fix minor stylistic issues
Fix checkpatch.pl errors and warnings:

* space before tab
* line over 80 characters
* include linux/ioctl.h instead of asm/ioctl.h

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-04-14 11:34:41 +03:00
Artem Bityutskiy 3efe509070 UBI: check if we are in RO mode in the erase routine
'do_sync_erase()' has to check whether we are in R/O mode before
erasing the PEB. This patch adds the check and while on it, adds an
assertion which validates the 'pnum' argument, as well as removes
a check which is always true because it has already been done
few lines before.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-04-05 11:08:58 +03:00
Artem Bityutskiy 3d46b316bc UBI: use GFP_NOFS properly
This patch fixes a brown-paperbag bug which was introduced by me:
I used incorrect "GFP_KERNEL | GFP_NOFS" allocation flags to make
sure my allocations do not cause write-back. But the correct form
is "GFP_NOFS".

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-03-24 16:09:56 +02:00
Artem Bityutskiy 92d124f531 UBI: make self-checks dynamic
This patch adds a possibility to dynamically switch UBI self-checks
on and off, instead of toggling them compile-time from the configuration
menu. This is much more flexible, and consistent with UBIFS, and this
also simplifies UBI Kconfig menu and the code.

This patch introduces two levels of self-checks - general, which
includes all self-checks which are relatively fast, and I/O, which
includes write-verify checks and erase-verify checks, which are
relatively slow and involve flash I/O.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-03-16 13:50:16 +02:00
Artem Bityutskiy 6f9fdf62db UBI: remove UBI_IO_DEBUG macro
This additional little macro is used to print a bit more messages
while scanning the media. However, we have the 'dbg_bld()' macro
for this, so we better us 'dbg_bld()' and kill UBI_IO_DEBUG. This
simplifies the code a tiny bit.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-03-16 13:50:16 +02:00
Artem Bityutskiy 332873d60b UBI: allocate erase checking buffer on demand
Instead of using pre-allocated 'ubi->dbg_peb_buf' buffer in
'ubi_dbg_check_all_ff()', dynamically allocate it when needed. The
intend is to get rid of the pre-allocated 'ubi->dbg_peb_buf' buffer
completely. And the need for this arises because we want to change
to dynamic debugging control instead of compile-time control, i.e.,
we are going to kill the CONFIG_MTD_UBI_DEBUG_PARANOID Kconfig
option, which would mean that 'ubi->dbg_peb_buf' is always allocated,
which would be wasteful.

Thus, we are getting rid of 'ubi->dbg_peb_buf', and this is a
preparation for that.

signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-03-16 13:50:16 +02:00
Artem Bityutskiy a75867432a UBI: allocate write checking buffer on demand
Instead of using pre-allocated 'ubi->dbg_peb_buf' buffer in
'ubi_dbg_check_write()', dynamically allocate it when needed. The
intend is to get rid of the pre-allocated 'ubi->dbg_peb_buf' buffer
completely. And the need for this arises because we want to change
to dynamic debugging control instead of compile-time control, i.e.,
we are going to kill the CONFIG_MTD_UBI_DEBUG_PARANOID Kconfig
option, which would mean that 'ubi->dbg_peb_buf' is always allocated,
which would be wasteful.

Thus, we are getting rid of 'ubi->dbg_peb_buf', and this is a
preparation for that.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-03-16 13:50:16 +02:00
Artem Bityutskiy a87f29cbbc UBI: always re-read in case of read failures
When the read operation fails, UBI tries to re-read several times in
a hope that one of the subsequent reads may succeed. However, currently
UBI re-reads only if MTD failed to read all data, but does not re-reads
if all the data were read, but with an integrity error (-EBADMSB). This
patch makes UBI to always re-try reading.

This should be useful for reading NAND pages with unstable bits -
re-reading may help to get correct data.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-02-06 19:35:26 +02:00
Artem Bityutskiy 7950d023c5 UBI: use raw mtd read function in debugging code
This change affects only the debugging code. Namely, use mtd->read()
function instead of ubi_io_read() to avoid bit-flips injection
(ubi_dbg_is_bitflip()) which we do not want on the debugging path.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-02-06 19:18:58 +02:00
Artem Bityutskiy 276832d878 UBI: try to reveal buggy MTD drivers
When reading data from the flash, corrupt the buffer we are about to
read to. The idea is to fix the following possible situation:

1. The buffer contains data from previous operation, e.g., read from
   another PEB previously. The data looks like expected, e.g., if we
   just do not read anything and return - the caller would not
   notice this. E.g., if we are reading a VID header, the buffer may
   contain a valid VID header from another PEB.
2. The driver is buggy and returns use success or -EBADMSG or
   -EUCLEAN, but it does not actually put any data to the buffer.

This may confuse UBI or upper layers - they may think the buffer
contains valid data while in fact it is just old data.

Thus, try to reveal such buggy MTD drivers with simple debugging
code which fills the read buffer with 0x12 constant.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-02-06 19:18:32 +02:00
Artem Bityutskiy 2fff570e7c UBI: add a commentary about allocating VID header buffer on stack
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-01-26 10:14:23 +02:00
Holger Brunck d4c6381303 UBI: fix NOR erase preparation quirk
In 'nor_erase_prepare()' we want to make sure the UBI headers are
corrupted. But it is possible that one of the headers just contains
all 0xFFs, which is also OK, because UBI will erase it in case of
a power cut.

Signed-off-by: Holger Brunck <holger.brunck@keymile.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-01-26 10:13:52 +02:00