walnux/drivers/spi
dongjiuzhu1 cfd359141f fs/drivers: Avoid causing a busy loop in the program due to context switching induced by sem_post.
examples:
There are two threads involved: thread A with a priority of 100 and
thread B with a priority of 101. Here's how they interact:

When thread A releases a semaphore, thread B is scheduled to execute
some code and may reacquire the semaphore. If no other tasks are ready,
thread A will be scheduled to run.
This continuous process can lead to a busy loop.

Thread A:                                                   Thread B:

while (nxsem_get_value(&priv->wait, &semcount) >= 0 &&  <---
       semcount <= 0)                                      |  2)context switch
  {                                  1)contex switch       |
    nxsem_post(&priv->wait);         ------------->     run some code and nxsem_wait again
  }

Signed-off-by: dongjiuzhu1 <dongjiuzhu1@xiaomi.com>
2025-03-17 10:44:26 +01:00
..
CMakeLists.txt drivers: migrate to SPDX identifier 2024-11-06 18:02:25 +08:00
ice40.c drivers/spi/ice40: migrate to SPDX identifier 2024-12-16 14:18:35 +08:00
Kconfig drivers/spi: Add support for FPGA iCE40 bitstream loading. 2024-04-12 10:19:58 -03:00
Make.defs drivers: migrate to SPDX identifier 2024-11-06 18:02:25 +08:00
qspi_flash.c drivers: migrate to SPDX identifier 2024-11-06 18:02:25 +08:00
spi_bitbang.c drivers: migrate to SPDX identifier 2024-11-06 18:02:25 +08:00
spi_driver.c drivers: migrate to SPDX identifier 2024-11-06 18:02:25 +08:00
spi_flash.c drivers: migrate to SPDX identifier 2024-11-06 18:02:25 +08:00
spi_slave_driver.c fs/drivers: Avoid causing a busy loop in the program due to context switching induced by sem_post. 2025-03-17 10:44:26 +01:00
spi_transfer.c drivers: migrate to SPDX identifier 2024-11-06 18:02:25 +08:00