OVMS3-idf/examples/peripherals/spi_master
michael fdf983e0c4 spi: fix config break and reduce overhead of the bus lock on SPI1
The SPI bus lock on SPI1 introduces two side effects:

1. The device lock for the main flash requires the
`CONFIG_FREERTOS_SUPPORT_STATIC_ALLOCATION` to be selected, however this
option is disabled by default in earlier IDF versions. Some developers
may find their project cannot be built by their old sdkconfig files.

2. Usually we don't need the lock on the SPI1 bus, due to it's
restrictions. However the overhead still exists in this case, the IRAM
cost for static version of semaphore functions, and the time cost when
getting and releasing the lock.

This commit:

1. Add a CONFIG_SPI_FLASH_BYPASS_MAIN_LOCK option, which will forbid the
space cost, as well as the initialization of the main bus lock.

2. When the option is not selected, the bus lock is used, the
`CONFIG_FREERTOS_SUPPORT_STATIC_ALLOCATION` will be selected explicitly.

3. Revert default value of `CONFIG_FREERTOS_SUPPORT_STATIC_ALLOCATION`
to `n`.

introduced in 49a48644e4.

Closes https://github.com/espressif/esp-idf/issues/5046
2020-04-22 16:06:13 +08:00
..
hd_eeprom spi: fix config break and reduce overhead of the bus lock on SPI1 2020-04-22 16:06:13 +08:00
lcd example: move spi master example to a subfolder 2020-03-29 12:52:29 +08:00