The existing spinlock mechanism possibly has an overlap of memory
operations during multi core execution, as visible in CI testing. When
running the example inter_cpu_critical_section, shared count increment
stops at 299999 instead of reaching 300000, but this only happens
randomly 1 out of 10 times. It is suspected that a memory operation
happens simultaneously from both core, even though spinlock protection
is in place.
To handle this problem, a memory barrier (fence instruction) is added
at critical places during spinlock acquire and release, to ensure that
all memory operations upto that point are completed and synchronised
before proceeding further.
lp_core_i2c.h header file has sda and scl pins hardcoded to GPIO6 and
GPIO7 which works only for ESP32C6. ESP32C5 uses GPIO2 and GPIO3 for
I2C SDA and SCL. Hence, added LP_I2C_SCL_IO and LP_I2C_SDA_IO macros
under conditional compilation in library header file, so there is no
need to hardcode I2C GPIO pins and any other test apps or examples
that are including the LP I2C header file can also use Macro directly.
Updated the i2c read/write APIs ulp_riscv_i2c_master_read_from_device
and ulp_riscv_i2c_master_write_to_device in ulp_riscv component to
return error codes back to the application
Closes https://github.com/espressif/esp-idf/issues/15904
Moved the error logs outside critical section for i2c communication errors
like READ fail, WRITE fail etc. in the ulp_riscv_i2c component
Also changed the error log API from ESP_EARLY_LOG to ESP_LOG, so we can support
tag based filtering and enabling/disabling of logs
Closes https://github.com/espressif/esp-idf/issues/17425
Meet Patel