While calculating speed during mtd_speedtest, the time interval
(i.e., start - finish) is rounded off to the nearest milliseconds by
ignoring the fractional part. This leads to miscalculation of speed.
The miscalculation is more visible while running speed test on small
partition sizes(i.e., when partition size is equal to eraseblock size or
twice the eraseblock size) at higher spi frequencies.
For e.g., while calculating eraseblock read speed for a mtd partition with
size equal to the eraseblock size(i.e., 64KiB) the eraseblock read time
interval comes out to be 966490 nanosecond. This is then converted to
millisecond(i.e., 0.966 msec.). The integer part (i.e., 0 msec) of the
value is considered and the fractional part (i.e., 0.966) is ignored,for
calculating the eraseblock read speed. So the reported eraseblock read
speed is 0 KiB/s, which is incorrect.
There are two approaches to fix this issue.
First approach will be to keep the time interval in millisecond. and round
up the integer value, with this approach the 0.966msec time interval in the
above example will be rounded up to 1msec and this value is used for
calculating the speed. Downside of this approach is that the reported speed
is still not accurate.
Second approach will be to convert the time interval to microseconds
instead of milliseconds, with this approach the 966490 nanosecond time
interval in the above example will be converted t0 966.490usec and this
value is used for calculating the speed. As compared to the current
implementation and the suggested First approach, this approach will report
a more accurate speed. Downside of this approach is that, in future if the
mtd size is too large then the u64 variable, that holds the number of
bytes, might overflow.
In this patch we have gone with the second approach as this reports a more
accurate speed. With this approach the eraseblock read speed in the above
example comes out to be 132505 KiB/s when the spi clock is configured at
150Mhz.
Signed-off-by: Amit Kumar Mahapatra <amit.kumar-mahapatra@xilinx.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20220208103905.13354-1-amit.kumar-mahapatra@xilinx.com
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 version 2 as
published by the free software foundation 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 see the file copying if not
write to the free software foundation 59 temple place suite 330
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extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 9 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190530000435.832876118@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
->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>
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>
Changes the 32-bit time type timeval to the 64-bit time type
ktime_t, since 32-bit systems using struct timeval will break in the
year 2038. Correspondingly change do_gettimeofday() to ktime_get()
since ktime_get returns a ktime_t, but do_gettimeofday returns a
struct timeval.Here, ktime_get() is used instead of ktime_get_real()
since ktime_get() uses monotonic clock.
Signed-off-by: Shraddha Barke <shraddha.6596@gmail.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
I always go nuts when I start an MTD test on a slow device and have to
wait forever until it finishes. From the debug output I already know
what the issue is but I have to wait or reset the board hard. Resetting
is often not an option (remote access, you don't want lose the current
state, etc...).
The solution is easy, check for pending signals at key positions in the
code. Using that one can even stop a test by pressing CTRL-C as
insmod/modprobe have SIGINT pending.
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
These multiplications are done with 32-bit arithmetic, then converted to
64-bit. We should widen the integers first to prevent overflow. This
could be a problem for large (>4GB) MTD's.
Detected by Coverity.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
All callers of mtdtest_write() print the same error message on failure.
This incorporates the error message to mtdtest_write() and removes them
from the callers.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
All callers of mtdtest_read() print the same error message on failure.
This incorporates the error message to mtdtest_read() and removes them
from the callers.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Each mtd test module have a single source whose name is the same as
the module name. In order to link a single object including helper
functions to every test module, this rename these sources to the
different names.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Vikram Narayanan <vikram186@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Amit Kumar Mahapatra
Thomas Gleixner
Boris Brezillon
Shraddha Barke
Richard Weinberger
Brian Norris
Akinobu Mita