The underlying i2c implementation would always block infinitely on reads #45
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…ad events if it didn't get an answer from the i2c device. This change adds the same timeout countdown we use elsewhere in the library.
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We should discuss before merging this. It's specced as a blocking read in the code comments, but I can't believe it's supposed to be a "lock your program hard" blocking read. |
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Ah, no. The upstream source function was specced as a blocking read. https://github.com/ARMmbed/mbed-os/blob/4587080dbb470294f623054db2a272f1570be327/targets/TARGET_GigaDevice/TARGET_GD32F30X/i2c_api.c#L267 |
maxgerhardt
approved these changes
Oct 2, 2021
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It's good that there's a timeout now, eventually we should move to specifying timeouts as microseconds because that's what e.g. the AVR Wire library is doing https://github.com/arduino/ArduinoCore-avr/blob/master/libraries/Wire/src/utility/twi.c#L216-L223 The Wire library is riddled with simply decrement-counter CPU delays which are extremely CPU clock sensitive. |
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The underlying i2c implementation would always block infinitely on read events if it didn't get an answer from the i2c device.
This change adds the same timeout countdown we use elsewhere in the library.