Files
esp-idf/components/driver
Armando 3c8f6dd1cf SPI_BUS_LOCK: fix a concurrency issue
define: lock_bits = (lock->status & LOCK_MASK) >> LOCK_SHIFT;  This `lock_bits` is the Bit 29-20 of the lock->status

1. spi_hdl_1:
   acquire_end_core():
   uint32_t status = lock_status_clear(lock, dev_handle->mask & LOCK_MASK);
   Becuase this is the first `spi_hdl_1`, so after this , lock_bits == 0`b0. status == 0

2. spi_hdl_2:
   acquire_core:
   uint32_t status = lock_status_fetch_set(lock, dev_handle->mask & LOCK_MASK);
   Then here status is 0`b0, but lock_bits == 0`b10. Because this is the `spi_hdl_2`

3. spi_hdl_2:
   `acquire_core` return true, because status == 0. `spi_bus_lock_acquire_start(spi_hdl_2)` then won't block.

4. spi_hdl_2:
   spi_device_polling_end(spi_hdl_2).

5. spi_hdl_1:
   acquire_end_core:
   status is 0, so it cleas the lock->acquiring_dev

6. spi_hdl_2:
   spi_device_polling_end:
   assert(handle == get_acquiring_dev(host)); Fail

Closes https://github.com/espressif/esp-idf/issues/8179
2022-09-06 16:59:02 +08:00
..
2022-08-17 06:31:50 +00:00
2022-01-18 10:06:08 +08:00
2022-07-27 15:08:58 +08:00
2022-08-08 08:30:09 +00:00
2022-08-08 08:30:09 +00:00
2021-05-25 17:43:57 +02:00
2021-05-25 17:43:57 +02:00