_acquire() function added & removed duplication in format/freq calls #4635
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1. Private _acquire() function is added to avoid multiple locking/unlocking 2. format and frequency functions updated to use appropriate function calls instead of a aquire()
deepikabhavnani
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drivers/SPI.cpp
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| SPI::_owner = NULL; // Not that elegant, but works. rmeyer | ||
| aquire(); | ||
| spi_frequency(&_spi, _hz); | ||
| _owner = this; |
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The owner can be changed here without ensuring that both frequency and format are set. The format setting maybe be incorrect on the next write since it was not updated.
A sequence similar to this would cause that:
spi_a.write(value_a) <-Internal call to _acquire will change owner and set frequency and format for SPI A
spi_b.frequency(freq_b) <- Owner changed to B and frequency set
spi_b.write(value_b) <- Interal call to _acquire won't change setting. Frequency will be set correctly for B and format will be set for A
drivers/SPI.h
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| @@ -270,6 +270,12 @@ class SPI { | |||
| int _bits; | |||
| int _mode; | |||
| int _hz; | |||
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| private: | |||
| /* Private acquire fucntion without locking/unlocking | |||
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A question, now we use |
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Private _acquire has no locking, but since we lock before using this function behavior will be same. We do not have virtual function for aquire in code base, but some user might be having it, hence old aquire API is kept unchanged. |
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/morph test |
Result: SUCCESSYour command has finished executing! Here's what you wrote!
OutputAll builds and test passed! |
Description
instead of a aquire()
Issue
#4626
Status
READY