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David Sidrane
c967cade47
backport 3cd66af889b42b036d6c9d88e067fc3b8abbdb2a and pr 258 Applies to STM32F4 and STM32F7 STM32, STM32 F7, and STM32 L4: Clone Freddie Chopin's I2C change to similar STM32 I2C drivers. 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.