linux-stable.git/drivers/mtd/mtdcore.c, branch linux-3.18.y

mtd: remove dead non-char logic

2014-08-19T18:53:08+00:00

MTD used to allow compiling out character device support. This was
dropped in the following commit, but some of the accompanying logic was
never dropped:

  commit 660685d9d1b4730f0b5ca97fa95f272f99c63bce
  Author: Artem Bityutskiy 
  Date:   Thu Mar 14 13:27:40 2013 +0200

      mtd: merge mtdchar module with mtdcore

The weird logic was flagged by Coverity.

Signed-off-by: Brian Norris 
Cc: Artem Bityutskiy

mtd: correct upper bounds check for mtd_*() APIs

2014-08-19T18:53:07+00:00

When checking the upper boundary (i.e., whether an address is higher
than the maximum size of the MTD), we should be doing an inclusive check
(greater or equal). For instance, an address of 16MB (0x1000000) on a
16MB device is invalid.

The strengthening of this bounds check is redundant for those which
already have a address+length check and ensure that the length is
non-zero, but let's just fix them all, for completeness.

Signed-off-by: Brian Norris

mtd: Introduce mtd_block_isreserved()

2014-07-09T01:38:16+00:00

In addition to mtd_block_isbad(), which checks if a block is bad or
reserved, it's needed to check if a block is reserved only (but not
bad). This commit adds an MTD interface for it, in a similar fashion to
mtd_block_isbad().

While here, fix mtd_block_isbad() so the out-of-bounds checking is done
before the callback check.

Signed-off-by: Ezequiel Garcia 
Tested-by: Pekon Gupta 
Signed-off-by: Brian Norris

mtd: Add sysfs attributes to expose the ECC stats fields

2014-07-09T01:37:26+00:00

These new sysfs device attributes allow us to retrieve the ECC and bad
block stats by poking a sysfs file, which is often more convenient than
using the ioctl.

Signed-off-by: Ezequiel Garcia 
Tested-by: Pekon Gupta 
Signed-off-by: Brian Norris

mtd: Fix the behavior of OTP write if there is not enough room for data

2014-03-11T05:42:31+00:00

If a write to one time programmable memory (OTP) hits the end of this
memory area, no more data can be written. The count variable in
mtdchar_write() in drivers/mtd/mtdchar.c is not decreased anymore.
We are trapped in the loop forever, mtdchar_write() will never return
in this case.

The desired behavior of a write in such a case is described in [1]:
- Try to write as much data as possible, truncate the write to fit into
  the available memory and return the number of bytes that actually
  have been written.
- If no data could be written at all, return -ENOSPC.

This patch fixes the behavior of OTP write if there is not enough space
for all data:

1) mtd_write_user_prot_reg() in drivers/mtd/mtdcore.c is modified to
   return -ENOSPC if no data could be written at all.
2) mtdchar_write() is modified to handle -ENOSPC correctly. Exit if a
   write returned -ENOSPC and yield the correct return value, either
   then number of bytes that could be written, or -ENOSPC, if no data
   could be written at all.

Furthermore the patch harmonizes the behavior of the OTP memory write
in drivers/mtd/devices/mtd_dataflash.c with the other implementations
and the requirements from [1]. Instead of returning -EINVAL if the data
does not fit into the OTP memory, we try to write as much data as
possible/truncate the write.

[1] http://pubs.opengroup.org/onlinepubs/9699919799/functions/write.html

Signed-off-by: Christian Riesch 
Signed-off-by: Brian Norris

mtd: Add a retlen parameter to _get_{fact,user}_prot_info

2014-03-11T05:42:28+00:00

Signed-off-by: Christian Riesch 
Cc: Artem Bityutskiy 
Signed-off-by: Brian Norris

mtd: convert to use ATTRIBUTE_GROUPS

2014-01-03T19:22:21+00:00

Use new ATTRIBUTE_GROUPS macro to declare attribute groups.

Signed-off-by: Axel Lin 
Signed-off-by: Brian Norris

mtd: remove duplicated include from mtdcore.c

2013-11-07T07:33:12+00:00

Remove duplicated include.

Signed-off-by: Wei Yongjun 
Acked-by: Ezequiel Garcia 
Signed-off-by: Brian Norris

mtd: Move major number definitions to major.h

2013-11-07T07:32:59+00:00

This patch moves the char and block major number definitions
to major.h to be with the rest of the major numbers.
While doing this, include major.h in the files that need it.

Signed-off-by: Ezequiel Garcia 
Signed-off-by: Brian Norris

mtd: add MTD_MLCNANDFLASH case for mtd_type_show()

2013-10-27T23:27:06+00:00

The current mtd_type_show() misses the MTD_MLCNANDFLASH case.
This patch adds the case for it, and also updates the ABI.

Signed-off-by: Huang Shijie 
Signed-off-by: Brian Norris