Writing to a flash sector while starting the erase of other sector
have a undefined behavior so lets add a semaphore and syncronize
access to Flash registers.
But for the semaphore to work it needs to be initialized so each
board needs call stm32_flash_initialize() on initialization, so
to avoid runtime problems it is only using semaphore and making
it thread safe if initialized, after all boards starts to call
stm32_flash_initialize() we can remove the boolean and the check.
Erase a sector from the second bank cause the bit 4 of SNB being set
but never unsed, so trying to erase a sector from the first bank
was acually eraseing a sector from the second bank.
Save elapsed time before handling I2C in stm32_i2c_sem_waitstop()
This patch follows the same logic as in previous fix to
stm32_i2c_sem_waitdone().
It is possible that a context switch occurs after I2C registers are read
but before elapsed time is saved in stm32_i2c_sem_waitstop(). It is then
possible that the registers were read only once with "elapsed time"
equal 0. When scheduler resumes this thread it is quite possible that
now "elapsed time" will be well above timeout threshold. In that case
the function returns and reports a timeout, even though the registers
were not read "recently".
Fix this by inverting the order of operations in the loop - save elapsed
time before reading registers. This way a context switch anywhere in the
loop will not cause an erroneous "timeout" error.
This patch follows the same logic as in previous fix to
stm32_i2c_sem_waitdone().
It is possible that a context switch occurs after I2C registers are read
but before elapsed time is saved in stm32_i2c_sem_waitstop(). It is then
possible that the registers were read only once with "elapsed time"
equal 0. When scheduler resumes this thread it is quite possible that
now "elapsed time" will be well above timeout threshold. In that case
the function returns and reports a timeout, even though the registers
were not read "recently".
Fix this by inverting the order of operations in the loop - save elapsed
time before reading registers. This way a context switch anywhere in the
loop will not cause an erroneous "timeout" error.
It is possible that a context switch occurs after stm32_i2c_isr() call
but before elapsed time is saved in stm32_i2c_sem_waitdone(). It is then
possible that the handling code was executed only once with "elapsed
time" equal 0. When scheduler resumes this thread it is quite possible
that now "elapsed time" will be well above timeout threshold. In that
case the function returns and reports a timeout, even though the
handling code was not executed "recently".
Fix this by inverting the order of operations in the loop - save elapsed
time before handling I2C. This way a context switch anywhere in the loop
will not cause an erroneous "timeout" error.
