The function call process is as follows:
	mtd_blktrans_work()
	  while (1)
	    do_blktrans_request()
	      mtdblock_writesect()
	        do_cached_write()
	          write_cached_data() /*if cache_state is STATE_DIRTY*/
	            erase_write()

write_cached_data() returns failure without modifying cache_state
and cache_offset. So when do_cached_write() is called again,
write_cached_data() will be called again to perform erase_write()
on the same cache_offset.

But if this cache_offset points to a bad block, erase_write() will
always return -EIO. Writing to this mtdblk is equivalent to losing
the current data, and repeatedly writing to the bad block.

Repeatedly writing a bad block has no real benefits,
but brings some negative effects:
1 Lost subsequent data
2 Loss of flash device life
3 erase_write() bad blocks are very time-consuming. For example:
	the function do_erase_oneblock() in chips/cfi_cmdset_0020.c or
	chips/cfi_cmdset_0002.c may take more than 20 seconds to return

Therefore, when erase_write() returns -EIO in write_cached_data(),
clear cache_state to avoid writing to bad blocks repeatedly.
Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

Looks like some drivers define MTD names with a colon in it, thus
making mtdpart= parsing impossible. Let's fix the parser to gracefully
handle that case: the last ':' in a partition definition sequence is
considered instead of the first one.
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Ron Minnich <rminnich@google.com>
Tested-by: Ron Minnich <rminnich@google.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

It's not used by anyone now, remove it. Fix the following gcc warning:

drivers/mtd/maps/physmap-gemini.c:49:34: warning: ‘syscon_match’ defined
but not used [-Wunused-const-variable=]
 static const struct of_device_id syscon_match[] = {
                                  ^~~~~~~~~~~~
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Richard Weinberger <richard@nod.at>

CFI changes:

* Support the absence of protection registers for Intel CFI flashes
* Replace zero-length array with flexible-arrays

Merge tag 'spi-nor/for-5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux into mtd/next

SPI NOR core changes:
- add, update support and fix few flashes
- prepare BFPT parsing for JESD216 rev D
- kernel doc fixes

Raw NAND core changes:
* Stop using nand_release(), patched all drivers.
* Give more information about the ECC weakness when not matching the
  chip's requirement.
* MAINTAINERS updates.
* Support emulated SLC mode on MLC NANDs.
* Support "constrained" controllers, adapt the core and ONFI/JEDEC
  table parsing and Micron's code.
* Take check_only into account.
* Add an invalid ECC mode to discriminate with valid ones.
* Return an enum from of_get_nand_ecc_algo().
* Drop OOB_FIRST placement scheme.
* Introduce nand_extract_bits().
* Ensure a consistent bitflips numbering.
* BCH lib:
  - Allow easy bit swapping.
  - Rework a little bit the exported function names.
* Fix nand_gpio_waitrdy().
* Propage CS selection to sub operations.
* Add a NAND_NO_BBM_QUIRK flag.
* Give the possibility to verify a read operation is supported.
* Add a helper to check supported operations.
* Avoid indirect access to ->data_buf().
* Rename the use_bufpoi variables.
* Fix comments about the use of bufpoi.
* Rename a NAND chip option.
* Reorder the nand_chip->options flags.
* Translate obscure bitfields into readable macros.
* Timings:
  - Fix default values.
  - Add mode information to the timings structure.

Raw NAND controller driver changes:
* Fixed many error paths.
* Arasan
  - New driver
* Au1550nd:
  - Various cleanups
  - Migration to ->exec_op()
* brcmnand:
  - Misc cleanup.
  - Support v2.1-v2.2 controllers.
  - Remove unused including <linux/version.h>.
  - Correctly verify erased pages.
  - Fix Hamming OOB layout.
* Cadence
  - Make cadence_nand_attach_chip static.
* Cafe:
  - Set the NAND_NO_BBM_QUIRK flag
* cmx270:
  - Remove this controller driver.
* cs553x:
  - Misc cleanup
  - Migration to ->exec_op()
* Davinci:
  - Misc cleanup.
  - Migration to ->exec_op()
* Denali:
  - Add more delays before latching incoming data
* Diskonchip:
   - Misc cleanup
   - Migration to ->exec_op()
* Fsmc:
  - Change to non-atomic bit operations.
* GPMI:
  - Use nand_extract_bits()
  - Fix runtime PM imbalance.
* Ingenic:
  - Migration to exec_op()
  - Fix the RB gpio active-high property on qi, lb60
  - Make qi_lb60_ooblayout_ops static.
* Marvell:
   - Misc cleanup and small fixes
* Nandsim:
  - Fix the error paths, driver wide.
* Omap_elm:
  - Fix runtime PM imbalance.
* STM32_FMC2:
  - Misc cleanups (error cases, comments, timeout valus, cosmetic
    changes).

Yes, staying withing 80 columns is certainly still _preferred_.  But
it's not the hard limit that the checkpatch warnings imply, and other
concerns can most certainly dominate.

Increase the default limit to 100 characters.  Not because 100
characters is some hard limit either, but that's certainly a "what are
you doing" kind of value and less likely to be about the occasional
slightly longer lines.

Miscellanea:

 - to avoid unnecessary whitespace changes in files, checkpatch will no
   longer emit a warning about line length when scanning files unless
   --strict is also used

 - Add a bit to coding-style about alignment to open parenthesis
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull x86 fixes from Thomas Gleixner:
 "A pile of x86 fixes:

   - Prevent a memory leak in ioperm which was caused by the stupid
     assumption that the exit cleanup is always called for current,
     which is not the case when fork fails after taking a reference on
     the ioperm bitmap.

   - Fix an arithmething overflow in the DMA code on 32bit systems

   - Fill gaps in the xstate copy with defaults instead of leaving them
     uninitialized

   - Revert: "Make __X32_SYSCALL_BIT be unsigned long" as it turned out
     that existing user space fails to build"

* tag 'x86-urgent-2020-05-31' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/ioperm: Prevent a memory leak when fork fails
  x86/dma: Fix max PFN arithmetic overflow on 32 bit systems
  copy_xstate_to_kernel(): don't leave parts of destination uninitialized
  x86/syscalls: Revert "x86/syscalls: Make __X32_SYSCALL_BIT be unsigned long"

Pull scheduler fix from Thomas Gleixner:
 "A single scheduler fix preventing a crash in NUMA balancing.

  The current->mm check is not reliable as the mm might be temporary due
  to use_mm() in a kthread. Check for PF_KTHREAD explictly"

* tag 'sched-urgent-2020-05-31' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/fair: Don't NUMA balance for kthreads

Pull networking fixes from David Miller:
 "Another week, another set of bug fixes:

   1) Fix pskb_pull length in __xfrm_transport_prep(), from Xin Long.

   2) Fix double xfrm_state put in esp{4,6}_gro_receive(), also from Xin
      Long.

   3) Re-arm discovery timer properly in mac80211 mesh code, from Linus
      Lüssing.

   4) Prevent buffer overflows in nf_conntrack_pptp debug code, from
      Pablo Neira Ayuso.

   5) Fix race in ktls code between tls_sw_recvmsg() and
      tls_decrypt_done(), from Vinay Kumar Yadav.

   6) Fix crashes on TCP fallback in MPTCP code, from Paolo Abeni.

   7) More validation is necessary of untrusted GSO packets coming from
      virtualization devices, from Willem de Bruijn.

   8) Fix endianness of bnxt_en firmware message length accesses, from
      Edwin Peer.

   9) Fix infinite loop in sch_fq_pie, from Davide Caratti.

  10) Fix lockdep splat in DSA by setting lockless TX in netdev features
      for slave ports, from Vladimir Oltean.

  11) Fix suspend/resume crashes in mlx5, from Mark Bloch.

  12) Fix use after free in bpf fmod_ret, from Alexei Starovoitov.

  13) ARP retransmit timer guard uses wrong offset, from Hongbin Liu.

  14) Fix leak in inetdev_init(), from Yang Yingliang.

  15) Don't try to use inet hash and unhash in l2tp code, results in
      crashes. From Eric Dumazet"

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (77 commits)
  l2tp: add sk_family checks to l2tp_validate_socket
  l2tp: do not use inet_hash()/inet_unhash()
  net: qrtr: Allocate workqueue before kernel_bind
  mptcp: remove msk from the token container at destruction time.
  mptcp: fix race between MP_JOIN and close
  mptcp: fix unblocking connect()
  net/sched: act_ct: add nat mangle action only for NAT-conntrack
  devinet: fix memleak in inetdev_init()
  virtio_vsock: Fix race condition in virtio_transport_recv_pkt
  drivers/net/ibmvnic: Update VNIC protocol version reporting
  NFC: st21nfca: add missed kfree_skb() in an error path
  neigh: fix ARP retransmit timer guard
  bpf, selftests: Add a verifier test for assigning 32bit reg states to 64bit ones
  bpf, selftests: Verifier bounds tests need to be updated
  bpf: Fix a verifier issue when assigning 32bit reg states to 64bit ones
  bpf: Fix use-after-free in fmod_ret check
  net/mlx5e: replace EINVAL in mlx5e_flower_parse_meta()
  net/mlx5e: Fix MLX5_TC_CT dependencies
  net/mlx5e: Properly set default values when disabling adaptive moderation
  net/mlx5e: Fix arch depending casting issue in FEC
  ...

NAND ECC modes (or providers) have their own enumeration but, unlike
their algorithms counterpart, there is no invalid or uninitialized
value to discriminate between an error and having chosen a no-ECC
situation. Add an "invalid" entry for this purpose.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://lore.kernel.org/linux-mtd/20200526195633.11543-7-miquel.raynal@bootlin.com

There is an enumeration to list ECC algorithm, let's use it instead of
returning an int.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://lore.kernel.org/linux-mtd/20200526195633.11543-6-miquel.raynal@bootlin.com

This scheme has been introduced for the Davinci controller and means
that the OOB area must be read *before* the rest of the data. This has
nothing to do with the ECC in OOB placement as it could be understood
and most importantly, there is no point in having this function out of
the Davinci NAND controller driver. A DT property for this scheme has
been added but never used, even by the Davinci driver which only uses
this scheme to change the default nand_read_page().

Move the main read_page() helper into the Davinci driver and remove
the remaining boilerplate.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://lore.kernel.org/linux-mtd/20200526195633.11543-4-miquel.raynal@bootlin.com

In new code, the use of typedef is discouraged. Turn this one in the
raw NAND core into a regular enumeration.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://lore.kernel.org/linux-mtd/20200526195633.11543-3-miquel.raynal@bootlin.com

Fix a probable copy/paste error: the function works like
mtd_ooblayout_set_bytes(), not *_get_bytes().
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://lore.kernel.org/linux-mtd/20200526195633.11543-2-miquel.raynal@bootlin.com

This helper is not very useful and very often people get confused:
they use nand_release() instead of nand_cleanup().

Now that all drivers have been converted to do not use nand_release()
anymore, let's remove this helper.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/linux-mtd/20200519130035.1883-63-miquel.raynal@bootlin.com

Reorganize ns_cleanup_module() to fit the reworked exit path of
ns_init_module().

There is no need for a ns_free_lists() function anymore, so drop it.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200525085851.17682-18-miquel.raynal@bootlin.com

Rename the "error" label to gave it a meaning.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200525085851.17682-17-miquel.raynal@bootlin.com

Lists are filled with calls to ns_parse_weakblocks(),
ns_parse_weakpages() and ns_parse_gravepages(). Handle them in the
error path, all at the same time.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200525085851.17682-16-miquel.raynal@bootlin.com

Drop the generic err_exit.

The remaining operation to do from this goto statement is to cleanup
the NAND allocations, so rename it.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200525085851.17682-15-miquel.raynal@bootlin.com

Free erase_block_wear on error, which is allocated by
ns_setup_wear_reporting().
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200525085851.17682-14-miquel.raynal@bootlin.com

Cosmetic change to give a meaning to all labels in this complicated
error path.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200525085851.17682-13-miquel.raynal@bootlin.com

nand_release() basically calls mtd_device_unregister() and
nand_cleanup(). Both helpers should be called after MTD device
registration and NAND scan, respectively. Drop nand_release() and use
the two helpers directly so that they fit the error path and the
labels there.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200525085851.17682-12-miquel.raynal@bootlin.com

ns_free() is the helper that is called symmetrically to ns_init() and
so should free the same objects, including the partition names.

Now, callers of ns_free() do not need to free this partition names
themselves.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200525085851.17682-11-miquel.raynal@bootlin.com

The nandsim device is allocated and initialized inside ns_init() by a
call to ns_alloc_device(), free it on error.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200525085851.17682-10-miquel.raynal@bootlin.com

The ns_init() function shall free the partition names allocated by
ns_get_partition_name() on error.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200525085851.17682-9-miquel.raynal@bootlin.com

The ns_alloc_device() helper has actually two distinct path. Handle
errors in both of them.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200525085851.17682-8-miquel.raynal@bootlin.com

Create a ns_debugfs_remove() helper for that and call it in
ns_cleanup_module().
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200525085851.17682-7-miquel.raynal@bootlin.com

Debugfs entries should be removed in the error path, so first, keep
track of them.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200525085851.17682-6-miquel.raynal@bootlin.com

Many function calls are done this way:

        if ((retval = func()) != 0)
	        return retval;

while we expect in the kernel function calls like:

        retval = func();
	if (retval)
	        return retval;

Apply this change where possible and also use "ret" instead of
"retval" in ns_init_module for consistency, as it is only used in this
function.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200525085851.17682-5-miquel.raynal@bootlin.com

Some functions are prefixed "nandsim_", others "ns_" and many are
simply not prefixed at all. Make this file consistent by prefixing all
functions by "ns_".

This is a mechanical change. Sometimes the line is a bit reworked as
well to fit the kernel coding style. For instance, there are several
places where displayed strings are cut. When one of this line is
changed because of the naming update, the two parts of the strings
gets concatenated.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200525085851.17682-4-miquel.raynal@bootlin.com

Symbolic permissions 'S_IRUSR' are not preferred. Checkpatch.pl
advises to use octal permissions '0400'.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200525085851.17682-3-miquel.raynal@bootlin.com

The nandsim object is called 'ns' almost everywhere, keep it that way
everywhere for consistency.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200525085851.17682-2-miquel.raynal@bootlin.com

v2.1: tested on Netgear DGND3700v1 (BCM6368)
v2.2: tested on Netgear DGND3700v2 (BCM6362)
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200522121524.4161539-6-noltari@gmail.com

Add brcm,brcmnand-v2.1 and brcm,brcmnand-v2.2 as possible compatible
strings to support brcmnand controllers v2.1 and v2.2.
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200522121524.4161539-5-noltari@gmail.com

Current pages sizes apply to controllers after v3.4
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200522121524.4161539-4-noltari@gmail.com

Only v3.3-v5.0 have a different CS0 layout.
Controllers before v3.3 use the same layout for every CS.

Fixes: 27c5b17c ("mtd: nand: add NAND driver "library" for Broadcom STB NAND controller")
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200522121524.4161539-3-noltari@gmail.com

These registers are also used on v3.3.
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200522121524.4161539-2-noltari@gmail.com

Drop the use of gpmi_copy_bits() in favor of the NAND helper
nand_extract_bits().
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200508171805.8627-1-miquel.raynal@bootlin.com