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author | Christian Riesch <christian.riesch@omicron.at> | 2014-03-06 12:42:37 +0100 |
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committer | Brian Norris <computersforpeace@gmail.com> | 2014-03-10 22:42:31 -0700 |
commit | 9a78bc83b4c31f67202b7b0a77fa25da732f44a3 (patch) | |
tree | 386d354b6cba9a22eca92c07ab10206c476c955a /drivers/mtd/nand/omap2.c | |
parent | ea6d833a3fddcd1d60414d48f34c7f4fbe88608f (diff) | |
download | op-kernel-dev-9a78bc83b4c31f67202b7b0a77fa25da732f44a3.zip op-kernel-dev-9a78bc83b4c31f67202b7b0a77fa25da732f44a3.tar.gz |
mtd: Fix the behavior of OTP write if there is not enough room for data
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 <christian.riesch@omicron.at>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Diffstat (limited to 'drivers/mtd/nand/omap2.c')
0 files changed, 0 insertions, 0 deletions